carburettor guide
DESCRIPTION
FB/EK Holden Stromberg carburettor enthusiasts guide.TRANSCRIPT
1
FB/EK HOLDEN
STROMBERG CARBURETTION
ENTHUSIASTS GUIDE
REVISION DATE UPDATE
0 October 2011 Initial draft for review.
2
Table of Contents 1 Background .................................................................................................................................................................. 3 2 Not all Strombergs Are Equal… the Zenith Connection ........................................................................................... 4
3 Decoding ...................................................................................................................................................................... 5
3.1 Stromberg Carburettor Model Numbers .................................................................................................................... 5
3.2 Australian Stromberg Carburettor Codes .................................................................................................................. 6
3.3 US Stromberg Carburettor Codes ........................................................................................................................... 14
4 Operation .................................................................................................................................................................... 15
4.1 BXOV-1 Main Components ..................................................................................................................................... 15
4.2 BXUV-2 and BXV-2 Main Components ................................................................................................................... 17
4.3 Float System ........................................................................................................................................................... 18
4.4 Idle System ............................................................................................................................................................. 18
4.5 Main Metering System............................................................................................................................................. 19
4.6 Accelerating System ............................................................................................................................................... 20
4.7 Power System ......................................................................................................................................................... 21
4.8 Choke System ......................................................................................................................................................... 21
4.9 Spacer ..................................................................................................................................................................... 22
5 Early Holden Stromberg Factory Specifications ..................................................................................................... 23
5.1 EH Holden S4 Carburettor ...................................................................................................................................... 33
6 Assembly Diagrams................................................................................................................................................... 34
6.1 BXOV-1 Assembly Diagram .................................................................................................................................... 34
6.2 BXUV-2/BXV-2 Assembly Diagram ......................................................................................................................... 35
7 Disassembly and Overhaul Process ........................................................................................................................ 38
7.1 Kit Contents and Pre-disassembly .......................................................................................................................... 38
7.2 Special Tools........................................................................................................................................................... 40
7.3 Removing the Carburettor from the Vehicle ............................................................................................................ 41
7.4 Disassembling the Air Horn ..................................................................................................................................... 41
7.5 Disassembling the Main Body ................................................................................................................................. 42
7.6 Disassembling the Throttle Body ............................................................................................................................. 44
7.7 Cleaning and Inspection .......................................................................................................................................... 45
7.8 Assembly and Reinstallation ................................................................................................................................... 46
7.9 Replacement Parts .................................................................................................................................................. 48
8 Tuning and Troubleshooting .................................................................................................................................... 52
8.1 Fuel Level ............................................................................................................................................................... 52
8.2 Idle Speed and Idle Mixture ..................................................................................................................................... 55
8.3 Accelerator Pump Stroke and Components ............................................................................................................ 56
8.4 Idle Vent Valve Lift .................................................................................................................................................. 59
8.5 Wide-Open Throttle (WOT) Adjustment................................................................................................................... 59
8.6 Main Metering Jets .................................................................................................................................................. 62
8.7 Power Bypass Jets .................................................................................................................................................. 66
8.8 Vacuum Power Piston ............................................................................................................................................. 68
8.9 Troubleshooting ...................................................................................................................................................... 70
9 Bigger Stromberg Swap ............................................................................................................................................ 79
10 Multiple Carburettors (Twins and Triples) ........................................................................................................... 81
10.1 Carburettor Model and Manifold Choice .................................................................................................................. 81
10.2 Linkages .................................................................................................................................................................. 82
10.3 Accelerator Linkage to Cable Modification .............................................................................................................. 88
10.4 Fuel and Vacuum Lines ........................................................................................................................................... 89
10.5 Venturi Sleeves ....................................................................................................................................................... 90
10.6 Synchronisation ....................................................................................................................................................... 91
10.7 Tuning ..................................................................................................................................................................... 92
10.8 Examples of Twin and Triple Setups (Stromberg Porn) ........................................................................................... 94
11 “The Joker” Carburettor Lock ............................................................................................................................ 127
12 Holden Part Numbers .......................................................................................................................................... 128
13 Bendix Stromberg Part Numbers ....................................................................................................................... 136
14 Contacts ............................................................................................................................................................... 148
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1 Background
This document aims to provide some information regarding carburettors suitable for FB and EK Holdens.
It contains:
historical information, such as which carburettors and fittings were fitted to different model Holdens,
practical information on identification, disassembly and reassembly of early Holden original and replacement carburettors, and
guidance on tuning, replacement parts and overhaul techniques.
It contains answers to many of the questions that seem to come up routinely on most of the early Holden
forums:
“What jets should I run in my early Holden, and where do I get them from?”
“Why is my Stromberg carburettor running so poorly?”
“How do I set up twin carburettors on a grey motor?”
The carburettors that are the subject of this document are Bendix Stromberg (Australia) B-Model. I will focus in this document on the single-barrel Stromberg carburettors, as the twin-barrel W-Model Strombergs are more the domain of the HK/HT/HG/HQ Holden enthusiasts. I will particularly focus on the BXOV-1 Stromberg, as it was fitted to most early Holdens (FX, FJ, FE, FC, FB, EK, EJ). The Stromberg BXOV-1 carburettor was also fitted to American Austin Company (later reorganized as American Bantam) BRC ¼ ton U.S. Army American Bantams, and to model 77, 440, CJ-2A and CJ-3A Willys. Apparently the tooling for the BXOV-1 carburettor was sold to Holden after American Bantam was dissolved. Whilst most of the information will relate to the single barrel B-Model carburettors, I will include some W-Model information where it is ready at hand and helps either clarify or close-out an issue (for example, I have included below the Stromberg and Holden parts numbers for the HR Holden 186S engine WW Stromberg carburettors so that the list contains all factory carburettors for FX-HR Holdens).
Whilst this document is primarily related to the FB and EK Holden carburettors, much of the information is
similar or identical to other early Holdens. Please bear in mind that the early Holden carburettors are
more than half a century old, and that limited documentation is known to exist other than references in
parts and workshop manuals (despite much hunting by enthusiasts, and both FE/FC and FB/EK Clubs).
Much of the information below is drawn from internet forums, discussion with enthusiasts and common
sense. I have used photos and other information from a wide variety of sources, particularly from the
forums – if anyone is offended by my use of the material, feels I have breached copyright or needs
recognition, please let me know and I will correct the issue immediately.
I would however like to thank the following for their patience and willingness to help me learn:
Keith Hoffmann, Richi Morgan, Wayne Bradford, Matto and Alex Smits for fantastic access to some
of the Workshop Manuals, Accelerator Magazines and accessory information.
Fingers, Thommo and a bunch of other forum members for answering questions along the way.
Stewart Watters, whose All Holden Day carburettor linkage photos I have pillaged.
Equally, I have made opinions and drawn conclusions on some of the information I have found and
equipment I have owned, and have cross-referenced a significant amount of printed material - if anyone
believes that I have made an error (or knows a better way to do something), please let me know and I will
update the document... after all, the main purpose here is to help other early Holden enthusiasts. I have
marked some text in red in this document where I am missing information – any help in closing these
gaps is appreciated.
Like all things automotive, installing, operating and maintaining a carburettor comes with a risk. Leaking
fuel lines can lead to fires, and items dropped down a carburettor throat can cause massive engine
damage (amongst other hazards). Any advice contained in this document is to be taken at the reader‟s
risk – qualified mechanics should be consulted where appropriate.
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2 Not all Strombergs Are Equal… the Zenith Connection
Stromberg carburettors were made by both Zenith and Bendix independently of each other, and are two very different pieces of equipment.
Zenith Carburettors was a British company, which joined rival Solex Carburettors in 1955. Over time the Zenith brand name fell into disuse. The rights to the Zenith designs were owned by Solex UK (a daughter company of Solex in France). Zenith Stromberg carburettors were installed in Armstrong Siddeleys, Austins, Humbers, Jaguars, Land-Rovers, MGs, Saabs Sunbeams, Sunbeam Talbots, Triumphs and Volvos. The Zenith Stromberg carburettors are of “constant depression” design, where the venturi size changes depending on engine load (SU carburettors work on the same principle). A typical Zenith Stromberg carburettor is shown in the image to the right. Zenith Strombergs were fitted to LC Holden 161S GTR-XU1 161S engines (triple 1.5” 150 CDS side draught), LJ Holden 202 XU1 engines (triple 175 CD2-S side draught) and HB Holden Brabham Toranas (single 150 CD side draught). Holden also used carburettors from this company (though not Stromberg models) on the HB Holden 1200cc, LC and LJ Torana 1200cc and 1600cc and LJ Torana 1300cc engines (Zenith) and the LH and LX Torana 1900cc engines (Solex). I will not focus on the Zenith Stromberg carburettors in this document – the Torana guys are a much better source of information for these carburettors.
The Bendix Corporation was an American manufacturing and engineering company which during various times in its sixty year existence (1924-1983) made brake systems, aeronautical hydraulics, avionics, radios, televisions and computers, and which licensed its name for use on home washing machines. Some history of the company is available at
http://en.wikipedia.org/wiki/Bendix_Corporation. The Bendix Stromberg carburettors are of fixed venturi design, and are more typical equipment for early Holdens. A typical Bendix Stromberg B-Model carburettor is shown in the image to the right. Note that whilst early Holden B-Model Strombergs are no longer manufactured, Stromberg Carburetor Ltd, an English company, owns the Stromberg trademarks and is now remaking Stromberg E-Model carburettors (the traditional hotrodder‟s Stromberg 97). Parts from Stromberg Carburetor Ltd will be discussed further in this document
I will refer to Bendix Strombergs carburettors as “Strombergs” for the remainder of this document. Single-barrel Stromberg carburettor were fitted to:
132.5ci FX, FJ, FE and FC Holden engines,
138ci, FB, EK, EJ Holden and LC and LJ Torana engines,
149ci EH and HD Holden engines,
161ci HR, HK, HT and HG Holden, LC, LJ, LH, LX and UC Torana and VB Commodore Holden engines (the LC 161S GTR engine used a two-barrel WW Stromberg),
173ci HQ and HJ Holden engines,
179ci EH and HD Holden engines (the HD X2 had twin single-barrel Strombergs),
186ci HR, HK, HT and HG Holden engines (the HR186S had twin single-barrel Strombergs, and the 186ci (186S) HK, HT and HG Holden engines had twin-barrel WW Strombergs),
202ci HQ and HJ (low compression) and HJ, HX, HZ Holden, LJ, LH, LX and UC Torana and VB Commodore engines (HQ 202ci normal compression engines used a two-barrel Stromberg).
The HG, HQ, HJ, HX HZ Holden, LH and LX Torana and VB Commodore 253ci engines used two-barrel WW Strombergs, completing the above list of Stromberg-equipped Holdens.
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3 Decoding
Stromberg carburettors have a Model number, a Code number and a Specification (for example for the
EK Holden manual engines, these are BXOV-1, 23-3000 and 2375000 respectively).
A given Model number (e.g. BXOV-1) may be used on many different types of vehicles (say Holdens
and Willys).
Bendix made several different Specifications for a given Model (for example the BXOV-1 had
Specifications 380228, 2375000 and 2375002 – whilst visually similar, some items such as the jets
change between different specifications).
The Code number tells you what Model and Specification went to which manufacturer and vehicle
(i.e. it‟s the link that tells you what car and engine combination a particular carburettor came from).
3.1 Stromberg Carburettor Model Numbers
The following information gives the basis of the factory Stromberg Model numbers, though is valid for
Stromberg carburettors produced after 1934. The Model number is sometimes, but not always cast into
the throttle body.
The first (and sometimes second) letter identifies the model. The Stromberg models are:
o A (an aero-type 2-barrel downdraught) ,
o B (a single barrel downdraught),
o E (a 2-barrel downdraught),
o OH (a single barrel horizontal),
o SF (a side-float heavy duty single barrel
updraught),
o UC (a single barrel updraught),
o W (a 2-barrel downdraught), and
o 4A (a 4-barrel downdraught).
A second letter identical to the first would
denote a 2-barrel carburettor (e.g. WW is a
2-barrel series W carburettor). Early Holden
Stromberg carburettors are normally B Models. Later model Holdens run WW Model Stromberg
carburettors. The legendary “Stromberg 97‟s” beloved of hotrodders world-wide were originally EE
Models, though there were 14 different 97‟s used in different vehicles.
The letter(s) following the model designation have the following meanings:
o B – a revision of AAV type (e.g. AAUVB),
o D – built-in dashpot (e.g. BXVD). The dashpot retards the closing of the throttle, allowing the fuel
charge to clear the manifold and prevent stalling when the accelerator is suddenly released,
o E – electrically controlled dashpot (e.g. BXVES),
o M – drain system incorporated (e.g. SFM),
o O – 1/8” oversize throttle barrel diameter (e.g. BXOV),
o P – vacuum actuated accelerator pump (e.g. AAVP),
o S – kickdown switch incorporated (e.g. AAVS). The kickdown switch allows the automatic
transmission to shift down from fourth to third gear at speeds of less than 35-40mph, giving
greater acceleration,
o U – 1/8” undersize throttle barrel diameter (e.g. BXUV),
o V – vacuum controlled power system (e.g. BXV), and
o X – cross flange (e.g. BXOV). A “cross flange” B model carburettor (BX…) has the flange bolts in
E 4A W SF
A B OH UC
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the same axis as the fuel inlet line, and at 90o to the throttle shaft. A “normal flange” B model
carburettor (B… - no X) has the flange bolts in the same axis as the throttle shaft, and at 90o
to the fuel inlet line.
The first number following the letters denotes the physical flange size of the carburettor and the
throttle barrel size:
o 1 – S.A.E. nominal size 1” flange with throttle barrel diameter of 13/16" and
23/8” bolt spacing (often referred to as a “Size 1” flange) ,
o 2 – S.A.E. nominal size 1¼” flange with throttle barrel diameter of 17/16" and
211
/16” bolt spacing (often referred to as a “Size 2” flange),
o 3 – S.A.E. nominal size 1½” flange with throttle barrel diameter of 111
/16" and 215
/16” bolt spacing
(often referred to as a “Size 3” flange),
o 4 – S.A.E. nominal size 1¾” flange with throttle barrel diameter of 115
/16” and 35/16” bolt spacing
(often referred to as a “Size 4” flange), and
o 5 – S.A.E. nominal size 2” flange with throttle barrel diameter of 2 2/16” and 3
9/16” bolt spacing
(often referred to as a “Size 5” flange).
Note that SF models carburettors do not follow the above convention. Note also that the “O” or “U”
letters will change the above throttle barrel diameters away from standard.
For some Strombergs there is a second number following the letters which denotes the automatic
choke style:
o 5 – electrically actuated automatic choke (e.g. BXOV-25)
o 6 – hot air actuated automatic choke (e.g. BXOV-26)
Finally, a third number following the letters (if present) denotes an integral Stromberg started switch:
o 7 – Stromberg starter switch (i.e.AAUVB-167)
So for 48, 53, FJ, FE, FC, FB, EK and EJ Holdens (BXOV-1) we have a single barrel downdraught
carburettor (B) with a cross flange (X), 1/8” oversize throttle (O) and vacuum controlled power system (V)
and an S.A.E. size 1 flange with barrel diameter of 13/16” (1). Note though that the “O” indicates an
1/8”
oversize throttle, so the real throttle barrel diameter is (13/16”+
1/8” =) 1
5/16”.
For Bendix Stromberg carburettors made prior to 1935 or made in the USA, and for Zenith Strombergs
carburettors, some further reference material is located here:
http://www.thecarburettorshop.com/Carburettor_ID.htm#IDStromberg.
Note that the above information gives a throttle barrel diameter, but does not give a venturi diameter (for
example, the BXUV-2 carburettor fitted to the Holden HD 149ci economy (taxi) engines (late 1965 – April
1966) and Holden HR, HK 161ci economy (taxi) engines (April 1966 – 1968) had a venturi diameter of
11/32”, whilst the BXUV-2 fitted to the Holden HD 179ci economy (taxi) engines (late 1965 – April 1966)
and Holden HR and HK 186ci economy (taxi) engines (April 1966 – 1968) had a different venturi of 13/32”
diameter (both had 15/16” diameter throttle barrels).
3.2 Australian Stromberg Carburettor Codes
The following are Stromberg carburettor codes for locally
produced carburettors. The code numbers are stamped
either on the air horn at the edge of the float chamber, on
a metal tag (air horn reinforcing bar) attached to the air
horn or stamped onto the main body casting below the
edge of the float chamber (late Australian BX castings) –
see diagram to the right.
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The codes are interpreted as follows:
The first section of numbers designates the make of vehicle. Letter(s) following the model
designation have the following meanings:
o 1 – Universal carburettor.
o 2- Ford
o 3 – Dodge
o 4 – Chrysler
o 6 – Studebaker
o 7 – Buick
o 15 - Plymouth
o 16 – De Soto
o 23 – General Motors Holden
o 32 – International Harvester Company
Note that US-made Strombergs use a different vehicle designation (see 3.3 below). US-made
Stromberg carburettors used the number 23 for General Motors Truck and Coach Division (GMTC)
rather than General Motors Holden. GMTC was originally the Yellow Coach bus manufacturer based
in Chicago. GM purchased a controlling interest in Yellow Coach in 1925, and the remaining shares
in 1943, renaming the company GMTC Division. GMTC Division manufactured interurban coaches
until 1980 and transit buses until 1987. GM withdrew from the bus and coach market because of
increased competition in the late 1980s.
The second section of numbers refers to a particular carburettor specification.
The letter suffix indicates an engineering change made to the specification (e.g. no letter is the first
produced specification, an “A” indicates a major change to that specification, a “B” indicates a
second major change etc).
So for 48, 50, FJ, FE, FE and early FC Holdens (23-105D), we have a carburettor manufactured for
General Motors Holden (23), with a specification of 380228 (105) which is at its fourth major engineering
change (D).
The table below lists the Stromberg carburettors made by Stromberg Australia for local vehicles. I have
also included carburettors supplied by Stromberg USA to the local market, which are noted as such in the
table. I have drawn the table above from a listing circulating on the Early Holdens forum together with
listings from the Bendix Corporation (Australia) Carburettor and Fuel Pump Service Parts Catalogue
(March 1968), from which I captured only Australian- or USA-built Stromberg carburettors. Some
Australian delivered cars are likely to have UK-sourced Stromberg carburettors (variable venturi), which I
have omitted.
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Code Model Specification Vehicle
1-92CA BXOV-2 A19102 Universal carburettor, 211
/16” flange bolt centres.
1-98C BXUV-3 A19103 Universal carburettor, 215
/16” flange bolt centres.
1-3400 BXUV-3 2375006 Universal carburettor, 215
/16” flange bolt centres.
1-3401 BXUV-3 2375011 Universal carburettor, 215
/16” flange bolt centres.
2-3101 BV-2 2375022 Ford Falcon XR 170ci engines (1966 – 1967).
2-3102 BV-2 2375023 Ford Falcon XR 200ci engines (1966 – 1967).
2-3103 BV-2 2375022 Ford Falcon XR 170ci engines (1966 – 1967).
2-3104 BV-2 2375023 Ford Falcon XR and 1967 Fairlane 200ci engines (1966 – 1967).
2-3105 BV-2 2375022 Ford Falcon XR 170ci engines (1966 – 1967).
2-3106 BV-2 2375023 Ford Falcon XR and 1967 Fairlane 200ci engines (1966 – 1967).
2-3108 BV-2 2375033 Ford Falcon XT 188ci automatic transmissions (1968).
2-3109 BV-2 2375034 Ford Falcon XT 221ci automatic transmissions (1968).
2-3111 BV-2 2375037 Ford Falcon XT 188ci manual transmissions (1968).
2-3112 BV-2 2375038 Ford Falcon XT 221ci manual transmissions (1968).
2-3116 BOV-2 2375046 Ford Falcon XW 221ci engines with manual and automatic transmissions (1969-1970).
2-3117 BV-2 2375047 Ford Falcon XW 188ci engines with manual and automatic transmissions (1970).
2-3118 BOV-2 2375048 Ford Falcon XY 250ci engines with manual transmissions (1970).
2-3119 BV-2 2375049 Ford Falcon XY 200ci engines with manual transmissions (1970).
2-3120 WW 2375053 Ford 1970 XW Falcon and ZC Fairlane 302ci V8 engines with automatic transmissions; 1970-1971 Ford
XY Falcon and ZD Fairlane 302ci V8 engines with manual and automatic transmissions.
2-3123 WW 2375054 Ford 1970 XW 302ci engines with manual transmissions.
2-3126 BOV-2 2375075 Ford Falcon XY 250ci engines with automatic transmissions (1970) and ZD 250ci engine.
2-3127 BV-2 2375076 Ford Falcon XY 200ci engines with automatic transmissions (1970).
2-3139 unknown unknown Ford XA 250ci engines with manual transmissions.
9
2-3147 unknown unknown Ford 1973-1974 XB;TC-D 250ci engines with automatic transmissions.
2-3148 unknown unknown Ford TC-TD;XB 250ci engines with manual transmissions.
2-3154 unknown unknown Ford TC;XA;ZF 250ci engines with automatic transmissions.
2-3156 unknown unknown Ford XA; ZF 302ci V8 engines with manual and automatic transmissions.
2-3163 unknown unknown Ford 1975-1976 XB,TC-D 250ci engines with automatic transmissions.
2-3170 unknown unknown Ford XC 3.3L engines with manual transmissions.
2-3171 unknown unknown Ford XC 4.1L engines with automatic transmissions.
2-3185 unknown unknown Ford 1977 XC 4.1L engines with automatic transmissions.
2-3190 unknown unknown Ford XC 4.1L engines with automatic transmissions.
2-3199 unknown unknown Ford 1979 XD;TF 250ci engines with automatic transmissions.
3-152 WW 380441 Dodge 960AV, 965AV, 990AV trucks with V8 engines (1958-1960). Note that this a Stromberg USA
carburettor.
3-204A WW 381019 Dodge AT4, AT5 and AT6 trucks with V8 engines (July – September 1962). Note that this a Stromberg
USA carburettor.
3-211 WW 381026 Dodge Phoenix SD2-M 1962. Note that this a Stromberg USA carburettor.
3-215 WW 381051 Dodge AT4, AT5 and AT6 trucks with V8 engines (September 1962-1967). Note that this a Stromberg
USA carburettor.
3-224 WW 381060 Dodge Phoenix TD2-M 1963. Note that this a Stromberg USA carburettor.
3-226 WW 381062 Dodge T series trucks with 313ci Canadian engines (late 1962-1967). Note that this a Stromberg USA
carburettor.
3-241 WW 381092 Dodge Phoenix VD-2 1964. Note that this a Stromberg USA carburettor.
3-259 WW 381157 Dodge Phoenix DB6 1966. Note that this a Stromberg USA carburettor.
3-273 WW 381193 Dodge Phoenix DC6 1967. Note that this a Stromberg USA carburettor.
4-3502 BXUV-3 2375012 Valiant VC (6 cylinder) and 145hp VE engines (1967 - 1968).
4-3503 BXUV-3 2375012 Valiant VC (6 cylinder) and 145hp VE engines (1967 - 1968).
6-123A WW 380954 Studebaker Lark without positive crankcase ventilation (1959-1961). Note that this a Stromberg USA
carburettor.
10
6-125 WW 381002 Studebaker Lark without positive crankcase ventilation (1961). Note that this a Stromberg USA
carburettor.
6-127 or
6-127A WW 381028
Studebaker Lark without positive crankcase ventilation (1962). Note that this a Stromberg USA
carburettor.
6-128 or
6-128A WW 381029 Studebaker Lark with positive crankcase ventilation (1962). Note that this a Stromberg USA carburettor.
6-130 WW 381067 Studebaker Lark with positive crankcase ventilation (1963-early 1964). Note that this a Stromberg USA
carburettor.
6-132 WW 381099 Studebaker Lark and Cruiser with positive crankcase ventilation (late 1964-1966). Note that this a
Stromberg USA carburettor.
15-42A WW 380971 Dodge PD44 V8 engines (1960). Note that this a Stromberg USA carburettor.
23-105D BXOV-1 380228 Holden 48, 50, FJ, FE, FE and early FC (1948-1959).
23-201A WW 381205 Holden HR, HK, HT and HG 186S engines with manual transmissions. Note that this a Stromberg USA
carburettor.
23-201B WW 381205 Holden HR, HK, HT and HG 186S engines with manual transmissions. Note that this a Stromberg USA
carburettor.
23-202 WW 381206 Holden HR, HK, HT and HG 186S engines with automatic transmissions. Note that this a Stromberg
USA carburettor.
23-202A WW 381206 Holden HR, HK, HT and HG 186S engines with automatic transmissions. Note that this a Stromberg
USA carburettor.
23-202B WW 381206 Holden HR, HK, HT and HG 186S engines with automatic transmissions. Note that this a Stromberg
USA carburettor.
23-3000 BXOV-1 2375000 Holden FC (late), FB, EK and EJ manual transmissions (1959 - 1963).
23-3001 BXOV-1 2375002 Holden EK and EJ automatic transmissions (1961 - 1963).
23-3002 BXUV-2 2375003 Holden EH 149ci engines (August 1963 - early 1964).
23-3003 BXV-2 2375005 Holden EH 179ci engines with manual and automatic transmissions (August 1963 – early 1964).
23-3005 BXUV-2 2375007 Holden EH 149ci engines with manual and automatic transmissions (early 1964 - February 1965).
11
23-3006 BXV-2 2375008 Holden EH 179ci engines with manual and automatic transmissions (early 1964 – February 1965).
23-3007 BXUV-2 2375009 Holden HD 149ci engines (February 1965 – April 1966).
23-3008 BXV-2 2375010 Holden HD 179ci engines (February 1965 – April 1966).
23-3009 BXUV-2 2375013 Holden HD 179ci X2 engines front carburettor (February 1965 – April 1966).
23-3010 BXUV-2 2375014 Holden HD 179ci X2 engines rear carburettor (February 1965 – April 1966).
23-3011 BXUV-2 2375017 Holden HD 149ci economy (taxi) engines (late 1965 – April 1966).
23-3012 BXUV-2 2375018 Holden HD 179ci economy (taxi) engines (late 1965 – April 1966).
23-3013 BXUV-2 2375009 Holden HD (February 1965 - April 1966), HR and HK (April 1966 – 1968) automatic transmissions, HT,
HG and LC 149ci and 161ci engines.
23-3014 BXV-2 2375010 Holden HD (February 1965 – April 1966), HR and HK (April 1966 – 1968), HT and HG 186ci engines
with automatic transmissions.
23-3015 BXUV-2 2375013 Holden HD (February 1965 – April 1966).179ci and HR (April 1966 – 1967) X2 engines with automatic
transmissions front carburettor.
23-3016 BXUV-2 2375014 Holden HD (February 1965 – April 1966).179ci and HR (April 1966 – 1967) X2 engines with automatic
transmissions rear carburettor.
23-3019 BXUV-2 2375024 Holden HR and HK (April 1966-1968), HT, HG and LC 161ci engines with manual transmissions.
23-3020 BXUV-2 2375025 Holden HR and HK (April 1966 – 1968), HT and HG 186ci engines with manual transmissions.
23-3021 BXUV-2 2375018 Holden HR and HK 186ci economy (taxi) engines (April 1966 – 1968).
23-3022 BXUV-2 2375017 Holden HR, HK 161ci economy (taxi) engines (April 1966 – 1968).
23-3023 BXUV-2 2375027 HR 186ci X2 engines with manual transmission rear carburettor (April 1966 – 1967).
23-3024 BXUV-2 2375027 HR 186ci X2 engines with manual transmission front carburettor (April 1966 – 1967).
23-3032 WW 2375039 Holden HT and HG 253ci V8 engines with automatic transmissions (1969/70).
23-3033 WW 2375040 Holden HT and HG 253ci V8 engines with manual transmissions (1969-1970).
23-3034 WW 2375043 Holden HT 186S engines with automatic transmissions (1969-1970).
23-3035 WW 2375044 Holden HT and HG 186S engines with manual transmissions (1969-1970).
23-3036 WW 2375050 Holden HG 186S engines with automatic transmissions (1970).
23-3039 BXUV-3 2375057 Bedford 300ci 6 cylinder engines from 1970 and 1971 (single barrel).
12
23-3040 WW Holden late HT and all HG 253ci V8 engines with manual transmission.
23-3041 WW 2375058 Holden LC GTR 161S (2600S) engines, from October 1969 to July 1971.
23-3043 BXUV-2 2375060 Holden HT low compression 161ci engines with automatic transmissions, 1970
23-3044 BXUV-2 2375061 Holden HT low compression 161ci engines with manual transmissions, 1970
23-3045 WW unknown Holden HQ 253ci V8 engines from July 1971 to October 1972.
23-3046 WW unknown Holden HQ 253ci V8 engines with manual transmissions (earlier carburettor).
23-3048 unknown unknown Holden LC 186S engines.
23-3050 unknown unknown Holden HQ, LC and LJ 173ci engines with manual transmissions.
23-3053 unknown unknown Holden HQ and LJ 202ci engines with automatic transmissions.
23-3054 unknown unknown Holden LC and LJ 138ci engines with manual transmissions.
23-3063 WW unknown Holden HQ 253ci V8 engines with automatic transmissions from November 1972 to July 1973.
23-3064 WW unknown Holden HQ 253ci V8 engines with manual transmissions (later carburettor, November 1972 onwards).
23-3073 unknown unknown Holden HQ 173ci engines with automatic transmissions.
23-3074 unknown unknown Holden HQ 173ci engines with manual transmissions.
23-3075 unknown unknown Holden HQ 202ci engines with automatic transmissions.
23-3076 unknown unknown Holden HQ 202ci engines with manual transmissions.
23-3077 WW unknown Holden HQ 253ci V8 engines with automatic transmissions from August 1973 to September 1974.
23-3078 WW unknown Holden HQ 253ci V8 engines with manual transmissions from August 1973 to September 1974.
23-3081 unknown unknown Holden LJ and LH Toranas, 173ci engines with automatic transmissions.
23-3082 unknown unknown Holden LJ and LH Toranas, 173ci engines with manual transmissions.
23-3083 unknown unknown Holden HJ and LJ and LH Toranas, 202ci engines with automatic transmissions.
23-3084 unknown unknown Holden HJ and LJ and LH Toranas, 202ci engines.
23-3085 unknown unknown Holden HJ and LH Torana, 253ci V8 engines with automatic transmissions.
23-3086 WW unknown Holden HJ 253ci V8 engines with manual transmissions.
23-3089 unknown unknown Holden 1975 LH and LX Toranas, 173ci engines with manual transmissions.
23-3090 unknown unknown Holden 1975 LH and LX Toranas, 173ci engines with automatic transmissions.
23-3091 unknown unknown Holden 1975 LH and LX Toranas and HJ 202ci engines with manual transmissions.
13
23-3093 WW unknown Holden HJ and LH and LX Toranas, 4.2L V8 engines with manual transmissions from January 1975 to
June 1977.
23-3094 WW unknown Holden HJ and LH and LX Toranas 4.2L V8 engines with automatic transmissions from January 1975 to
June 1977.
23-3098 WW unknown Holden HX and LX Torana 4.2L V8 engines with automatic transmissions from July 1976 to April 1977.
23-3099 WW unknown Holden HX and LX Torana 253ci V8 engines with manual transmissions.
23-3100 unknown unknown Holden LX and UC Toranas, 173ci engines with automatic transmissions.
23-3101 unknown unknown Holden LX and UC Toranas, 173ci engines with manual transmissions.
23-3102 unknown unknown Holden HX and LX Torana, 202ci engine with automatic transmissions.
23-3103 unknown unknown Holden HX and LX Torana 202ci engine with manual transmissions.
23-3105 unknown unknown Holden HX and HZ 202ci engine with automatic transmissions (utility and panelvan).
23-3106 unknown unknown Holden HX and HZ 202ci engine with manual transmissions (exchange utility).
23-3107 unknown unknown Holden HX and HZ and LX Toranas, 202ci engine with manual transmissions.
23-3109 unknown unknown Holden HX and HZ 202ci engine with manual transmissions.
23-3111 WW unknown Holden HX and HZ, LX Torana and VB Commodore 4.2L V8 engines with automatic transmissions from
May 1977 to March 1980.
23-3112 WW unknown Holden HX and HZ, LX Torana and VB Commodore 4.2 V8 engines with manual transmissions from May
1977 to March 1980.
23-3114 unknown unknown Holden HZ and LX and UC Toranas, 202ci engines with automatic transmissions.
23-3115 unknown unknown Holden HX and LX and UC Toranas, 202ci engines with manual transmissions.
23-3118 unknown unknown Holden VB Commodore 173ci engine with manual transmissions.
23-3120 unknown unknown Holden VB Commodore 202ci engine manual transmissions.
32-3300 BXUV-3 2375001 International Harvester AB160, AB162, AB182, ABT182, AACO172, AACO182, AACO183 and
AACOT182 (1962 – mid 1965), ABM160, ABM162 and ABM164 engines (late 1963 – mid 1965)
32-3301 BXUV-3 2375015 International Harvester AB160, AB162, AB164, AB182, ABT182, AACO172, AACO182, AACO183,
AACOT182, ABM160, ABM162 and ABM164 (mid-1965 – 1968).
32-3302 BXUV-3 2375019 International Harvester AC1100, AC1200, AC1300, AC1500, AC1510, AC1600 and AC4X4 (late 1966 –
14
1968).
3.3 US Stromberg Carburettor Codes
As noted above, US-made Stromberg carburettors do not use the same number designation for vehicle manufacturers as the Australian-made
Strombergs (for the code numbers stamped either on the air horn at the edge of the float chamber, on a metal tag (air horn reinforcing bar)
attached to the air horn). This make identification difficult if a carburettor has been sourced from the US. The following table indicates the US-
made codes:
No. Manufacturer No. Manufacturer No. Manufacturer
1 Standard carburettor 31 Autocar Motor Truck Company 106 Kenworth Truck Company
2 Ford 32 International Harvester Company 108 Minneapolis-Moline Power Implement
Company
3 Dodge 34 Continental Motor Corporation 109 Twin Coach Company
4 Chrysler 35 Buda Motor Company 121 Clark Tractor
5 Oldsmobile 39 Universal Motor Company 124 Vulcan Iron Works
6 Studebaker 40 Lincoln Motor Car Company 128 Allis Chalmers
7 Buick 41 Lycoming Motor Manufacturing
Company 130 LeRoi Motor Company
8 Nash 49 Brockway Motor Truck Company 133 Vaughan Motor Company
10 Packard 51 Climax Engineering Company 135 Ward LaFrance Truck
11 Lasalle 60 Koehring 147 Whitcomb Locomotive Company
12 Reo 64 The Corbitt Company 149 Bucyrus-Erie Company
13 Pontiac 66 Diamond T Company 153 Lima Locomotive Works
14 Chevrolet 70 Available Truck Company 165 Universal Crane Company
15 Plymouth 71 Ahrens-Fox 185 Fairmont Railway Motor Company
16 Desoto 82 Federal Truck 205 Cadillac
22 Hudson 83 Harnischfeger 213 Caterpillar Tractor
23 General Motors Truck and Coach
Division 88 Thew Shovel Company 219 Austin Manufacturing Company
24 Mack (International Motor
Company) 89 Byers Machine Company 256 Flexible Company
25 Wisconsin Motor Company 92 Fate-Root-Heath Company 265 Checker Cab
26 Waukesha Motor Company 96 Willys-Overland 266 Kaiser-Frazer
27 Hercules Motor Company 97 Seagrave Company
29 White Motor Company 99 American LaFrance
15
4 Operation
The Stromberg BXOV-1 carburettor has five basic systems that work together to provide the correct
fuel/air mixture over different engine loads:
The float system, which keeps a consistent level of liquid fuel “ready to go” in the carburettor,
The idle system, which controls the fuel/air mixture at no-throttle and slight-throttle operation.
The main metering system, which controls the fuel/air mixture at mid-throttle (or “cruise”) operation,
The accelerating system, which adds a small “shot” of fuel when you initially put your foot down,
The power system, which controls the fuel/air mixture at heavy throttle (hills, towing or race)
operation.
The choke system, which controls the air/fuel mixture for cold starting and warm-up.
Each of these systems will be described below. Note that the BXV-2 and BXUV-2 carburettors fitted to
EH, HD and HR Holdens operate identically.
4.1 BXOV-1 Main Components
The following diagram shows the main components of the Stromberg BXOV-1 carburettor:
16
1. Venturi – increases the air velocity in the carburettor.
1A. Booster venturi – amplifies the vacuum applied to the main metering and power systems.
2. Accelerator pump discharge nozzle – sprays (atomises) fuel from accelerator pump shot.
3. Main discharge jet – mixes air and fuel and controls the combined quantity that is discharged
from either the main metering system or the power system.
4. Float chamber vent – vents float chamber to atmosphere to keep mixtures set even if air cleaner
fouls.
5. Choke valve – restricts air supply to provide a rich mixture for starting and warm-up.
6. High speed air bleeder – meters the air that is fed to the main metering system and the power
system.
7. Idle air bleed – meters the air that is fed into the idle system (both 1st and 2
nd stages).
7A. Idle tube – meters the fuel for the idle system (both 1st and 2
nd stages).
8. Vacuum power piston – opens up under heavy load (low manifold vacuum) to allow fuel to flow to
the power system.
9. Accelerator pump – provides a “shot” of fuel when the accelerator is pressed down to enable
smooth and rapid acceleration.
10. Float – maintains the fuel in the float chamber at a set level.
11. Float needle and seat – opened and closed by the float to allow fuel into the float chamber.
12. Throttle valve – controls the amount of fuel and air that is admitted into the intake manifold and
hence sets the speed of the engine.
13. Idle discharge holes – discharges the fuel/air mixture from the idle system.
14. Idle needle valve – controls the quantity of fuel/air mixture that is discharged from the 1st stage
idle system.
15. Main metering jet – meters the fuel that is delivered by the main metering system during “cruise”
operation.
16. Power bypass jet – meters the fuel that is delivered by the power system during high speed or
heavy load operation.
17. Accelerator pump bypass jet – acts as a non-return valve to prevent the accelerator pump
drawing in air as it recharges, and determines the rate that the fuel “shot” is delivered to the
carburettor.
18. Accelerator pump check valve – admits fuel from the float bowl into the accelerator pump when it
is recharging, and prevents fuel flowing back again when the accelerator pump is discharging.
17
4.2 BXUV-2 and BXV-2 Main Components
The following diagram shows the main components of the Stromberg BXOV-1 carburettor:
Note that this is identical to the diagram in Section 4.1 above, with the following additions:
14A. Restrictor Wire – reduces the cross-sectional area of the idle passage to assist hot starting.
19. Vent valve – vents the float bowl to atmosphere under idle conditions to assist hot starting.
18
4.3 Float System
Fuel from the fuel tank is fed via the fuel pump to the carburettor. If the fuel level is too low, the float
(basically a hollow brass ball that floats on the
fuel in the float chamber) drops down and
opens the float needle valve. This allows the
pressurised fuel to enter the carburettor and
begin filling the float chamber. Once the fuel
level is high enough, the float rises, and
closes off the float needle valve. The float
chamber is vented by an internal passage to
the air horn. This balanced pressure ensures
that fuel/air mixtures stay constant even if the
air filter is blocked by dirt.
4.4 Idle System
Under very low engine speeds (idling), the engine does not produce enough vacuum to suck sufficient
fuel from the main metering system (due to the near-closed throttle plate). However, under the throttle
plate a high vacuum exists. This vacuum is used to pull fuel from the idle system. The idle system has a
first and second stage. The diagram below to the left shows the first stage operating, whilst the diagram
to the right shows the second stage operating.
When the engine is idling (first stage or foot fully off the accelerator), the throttle valve is held open very
slightly by the slow idle adjusting screw. By turning the screw, the throttle plate can be opened, letting
more fuel and air into the engine and increasing the idle speed. With the throttle plate pretty much closed,
almost all the vacuum created by the pistons moving downward (“manifold vacuum”) is concentrated on
the lower idle discharge hole under the throttle valve. This “sucks” the fuel from the float bowl, past the
main metering jet and through the idle tube. The idle tube has a very small “metering orifice” or hole in the
end which meters the amount of fuel. Even though the fuel is flowing through both the idle tube and the
main metering jet, the idle tube does most of the metering (or controlling) of the fuel flow. This is because
the idle tube metering orifice is about half the diameter of the main metering jet (much more restrictive).
From the idle tube the fuel is sucked through a connecting passage and past the idle air bleed. The idle
air bleed mixes in air to form an emulsion, which then keeps passing through the passage and then flows
out of the lower idle discharge hole. The amount of fuel/air mixture which passes is regulated by the idle
needle valve – screwing it in lets less fuel/air emulsion flow (leaner), screwing it out lets more fuel/air
emulsion flow (richer). The idle air bleed also acts as a vent to prevent siphoning of fuel from the idle
system at high speeds or when the engine is shut off.
19
The second idle stage comes into play as the throttle starts to open (initial take off from start). As the
throttle valve opens, the upper two idle discharge holes are uncovered, and the manifold vacuum can
then begin to draw (or “suck”) fuel from them. Note that although the upper two and lower idle discharge
holes take fuel/air emulsion from the same place, the idle needle valve only change the operation of the
lower idle discharge hole (1st stage).
4.5 Main Metering System
As the throttle is opened more, the manifold
vacuum is able to act on the main metering
system. Fuel is sucked from the float chamber
through the main metering jet. The size of the
hole in the main metering jet determines how
much fuel can flow. The fuel then flows to the
base of the main discharge jet. The fuel flows
through two drillings in the lower squared section
of the jet, then up the jet annular. As it flows it
passes the high speed air bleed, which mixes in
air to form an emulsion. The emulsion then
passes out the main discharge jet. The main
discharge jet also plays a critical role in setting
the mixture. Normally, as the air flows through
the carburettor, the proportion of fuel drawn from
the main metering system would increase due to
the petrol becoming more volatile under reduced
pressure. This would mean that as engine speed
increased, the mixture would get overly rich at cruise conditions. To prevent this, the main discharge jet
has a series of internal air holes. The holes allow the air from the high speed bleeder to mix in. At low
engine speeds, the low venturi suction allows the liquid level inside the main jet (coloured red in the
diagrams below) to sit high in the jet (the diagram to the left). This blocks off a lot of the air holes,
reducing the amount of air getting into the fuel mixture. As engine speed increases, the increased venturi
20
suction makes the fuel level drop down in the jet (the diagram to the right). This uncovers more of the air
holes, letting more air get into the fuel mixture so that the mixture remains constant. The dome shaped
high-speed air bleed also condenses any fuel vapour that forms in a hot carburettor after engine
shutdown, helping to prevent fuel percolation (boiling). The main discharge jet is located inside a booster
venturi. This is a small venturi inside the main venturi, which helps to increase the vacuum signal (or
“suck”) seen by the main metering system. Using a booster venturi means that the carburettor delivers
good low-speed throttle response without having to use a smaller (restrictive) main venturi. Whilst the idle
system is still in operation when the main metering system is running, the amount of fuel it delivers is far
less than the main metering system at “cruise” conditions.
4.6 Accelerating System
To allow smooth acceleration when the
accelerator pedal is first pushed down, an
extra “shot” of fuel is needed. The accelerator
pump is a piston pump which is mechanically
connected to the throttle. When the throttle is
pushed down, the connections drive the
accelerator pump piston down, forcing fuel
past the pump bypass jet. The pump check
valve assembly closes to stop fuel flowing
backwards into the float bowl. The restriction
of the accelerator pump bypass jet causes
the accelerator pump spring to compress as
the piston is slowed down. The pump is a
positive displacement unit and pumps the
same volume regardless of the jet size – the
jet just determines how fast the “shot” is
released. Fuel flows through a passage to the
accelerator pump discharge nozzle. The
nozzle atomises the fuel before it is sprayed into the carburettor (as the accelerator system has no air
bleed to make an emulsion). As the throttle is released, the accelerator pump piston is drawn back
21
upwards. The accelerator pump bypass jet closes to stop air being sucked in from the carburettor, and
the pump check valve opens to allow fuel to refill the pump from the float chamber, ready for the next
“shot”. Note that the chamber immediately surrounding the pump discharge nozzle is vented through the
float chamber vent tube to prevent fuel being drawn from the pump circuit at high engine speeds by the
high venturi vacuum.
4.7 Power System
When running under heavy load (high speed,
towing, travelling up hills or racing), a richer
mixture is required. The power system utilizes
a small piston which is normally help “up” by
manifold vacuum. The piston is balanced (one
side sees manifold pressure and the other
sees air horn pressure – see red vacuum
channels in the diagram to the right), with a
spring trying to push the piston down. Under
heavy load conditions the manifold pressure
drops to 4-6” Hg (2-3psi), and the vacuum
power piston is released downwards to push
on the power bypass jet stem. This allows fuel
to flow from the float chamber through the
power bypass jet, up the main discharge jet
(mixing with air from the high speed bleed)
and out the main discharge jet. This process
“bypasses”, or adds fuel in addition to, the
main metering jet (i.e. under heavy load both the main metering system and the power system are
operational).
4.8 Choke System
Whilst BX-Model carburettors were fitted with either
manual, electric or hot-air chokes, early Holden single-
barrel Strombergs are all fitted with manual chokes.
When starting a cold engine, a richer than normal
mixture is required (because the slowly-spinning engine
produces little vacuum to draw out fuel, and much of the
fuel condenses on the cold inlet manifold walls). To do
this, the choke valve is shut, restricting air into the
carburettor. The choke valve is connected by a
mechanical linkage (the fast idle cam) to the throttle
valve . When the choke valve is shut, the throttle valve
is cracked open. When the choke is opened, the throttle
returns to its normal position. The choke valve has a
light spring, which provides some “slop” in the choke
plate. The “slop” allows the choke valve to open slightly
once the engine fires. The choke valve is also fitted with
a spring-loaded poppet valve. When the engine starts, if
the choke plate is jammed shut (choke lever pulled all
22
the way out), the increased vacuum opens the poppet valve, relieving some of the suction on the idle
system and preventing flooding. A light buzzing noise from the poppet valve washer can be heard if the
engine is being overchoked in this fashion.
4.9 Spacer
Early Holdens used a spacer (often referred to as a phenolic or Bakelite spacer, or heat insulator)
between the carburettor and inlet manifold. The purpose of this spacer was to prevent heat soaking from
the inlet manifold into the carburettor, causing percolation (fuel boiling) and poor fuel flow. When vehicles
are fitted with extractors, the spacer may be able to be removed, as the heat-sink into the inlet manifold is
considerably less.
23
5 Early Holden Stromberg Factory Specifications
I have drawn the table below by cross-referencing the following sources:
The Bendix Corporation Australia (Automotive) Pty Ltd Stromberg Carburettor Service Manual No.
BM1 issued August 1968, together with the Stromberg Service Manual Supplement issued
November 1970 (Part No. SM1).
The Bendix Corporation Australia (Automotive) Pty Ltd Carburettor & Fuel Pump Service Parts
Catalogue No. PC2 Issued March 1968.
The Holden Workshop Manual (48/215 Manual)
The Holden FJ Workshop Manual
The Holden FE and FC Workshop Manual.
The Holden EK Workshop Manual.
The Holden „FB‟ Workshop Manual.
The Holden „EJ‟ „EH‟ Workshop Manual.
The Holden HD Workshop Manual.
The Holden HR Workshop Manual.
The Master Parts Catalogue (20 Years of Holden Production).
The Scientific Publications Workshop Manual Series No. 67 Holden covering series 1948/‟53 FJ, FE,
FC, FB, EK, EJ, EH, HD, HR.
The Scientific Publications Workshop Manual Series No. 86 Holden covering series HK, HT, HG
(whilst this document does not aim to examine HK/HT/HG Holdens, the HR, HK, HT and HG Holden
186S engines have identical WW Stromberg carburettors).
I have used the Bendix Corporation Australia (Automotive) Pty Ltd Stromberg Carburettor Service Manual
No. BM1 issued August 1968 as the starting point of the table, as it appears to be the most
comprehensive and complete table available. I have added additional information from the above
references, and have added notes throughout the table where that information is contradictory to the
Bendix Corporation Australia (Automotive) Pty Ltd Stromberg Carburettor Service Manual No. BM1
issued August 1968.
24
Vehicle (NOTE 1)
Holden 48, 50, FJ, FE, FE and early FC (1948-1959).
Holden FC (late), FB, EK and EJ
manual transmissions (1959 - 1963).
Holden EK and EJ automatic transmissions (1961 - 1963).
Holden EH 149ci engines (August
1963 - early 1964).
Holden EH 149ci engines with manual and automatic
transmissions (early 1964 -
February 1965).
Holden EH 179ci engines with manual and automatic
transmissions (August 1963 –
early 1964).
Holden EH 179ci engines with manual and automatic
transmissions (early 1964 –
February 1965).
Holden HD 149ci economy (taxi) engines (late 1965 – April 1966) and
Holden HR, HK 161ci economy (taxi) engines (April 1966 –
1968).
Holden HD 179ci
economy (taxi) engines (late 1965 – April 1966) and Holden HR
and HK 186ci economy (taxi) engines (April 1966 – 1968).
Stamping 23-105D 23-3000 23-3001 23-3002 23-3005 23-3003 23-3006 23-3011 and 23-
3022
23-3012 and 23-
3021
Model BXOV-1 BXUV-2 BXV-2 BXUV-2 BXUV-2 (NOTE
44)
Specification 380228 2375000 2375002 2375003 2375007 2375005 2375008 2375017 2375018
Flange size SAE 1” size cross flange with 2
3/8” bolt
spacing SAE 1¼” size cross flange with 2
11/16” bolt spacing
Main venturi diameter 1
1/32” 1
3/32” 1
5/32”
11/32”
(NOTE 45) 1
3/32”
Throttle bore 15/16” 1
7/16” 1
5/16”
Main metering jet 0.051”
(NOTE 2)
0.055” (NOTE 3)
0.059” (NOTE 4) (NOTE 5)
0.059” (0.058”
fitted from August 1964)
(NOTE 5)
0.051” (NOTE 6)
0.055” (NOTE 7)
Main discharge jet (NOTE 8)
28-34 (NOTE 57)
28-30 28-30 28-36
(NOTE 9) 28-30
High speed bleeder #70 drill (0.0280”) (NOTE 10)
Idle tube #70 drill (0.0280”). #70 drill (0.0280”)
(NOTE 11)
#68 drill (0.0310”)
(NOTE 12)
#70 drill (0.0280”)
#68 drill (0.0310”)
(NOTE 13)
#70 drill (0.0280”)
(NOTE 14)
#68 drill (0.0310”) (NOTE
15)
Idle air bleed #52 drill (0.0635”) #52 drill
(0.0635”) (NOTE 16)
#53 drill (0.0595”)
(NOTE 17)
0.054” (NOTE 18)
#52 drill (0.0635”)
(NOTE 19)
#53 drill (0.0595”) (NOTE
20) Idle discharge
holes #56-64-70 drill (0.0465-0.0360-0.0280”) #56-58 drill (0.0465- #56-64-70 drill (0.0465-
25
0.0420”) 0.0360-0.0280”) Idle screw setting
7/8 turn out 1 turn out
Power bypass jet #67 drill (0.0320”)
(NOTE 21) #65 drill (0.0350”)
(NOTE 21) #56 drill (0.0465”)
(NOTE 22) #55 drill (0.0520”)
(NOTE 23)
#65 drill (0.0350”)
(NOTE 24)
#56 drill (0.0465”) (NOTE
25) Pump bypass jet #56 drill (0.0465”) Pump discharge
jet #70 drill (0.0280”) #72 drill (0.0250”) Pump capacity
per stroke 0.83cc 0.5-0.8cc
Float needle seat orifice diameter
(NOTE 26) 0.070”
0.073” (NOTE 27)
0.073”
0.092”
0.073” 0.092”
Float bench setting
1/8”
Fuel level at 3psi (NOTE 28)
5/8-
11/16”
Pump link setting Middle Pump stroke – bench setting
17/64-
19/64”
7/32-
19/64”
Pump stroke – vehicle setting
(NOTE 29)
13/64-
15/64” (NOTE 58)
5/32-
15/64” (NOTE 30)
5/16-
17/64” (NOTE 31)
5/32-
15/64” (NOTE 46)
Vent valve lift (NOTE 32) - 0.040-0.060” 0.040-0.060” (NOTE 47)
Vehicle (NOTE 1)
Holden HD (February 1965 - April 1966), HR and HK (April
1966 – 1968) automatic
transmissions, HT, HG and LC 149ci and
161ci engines.
Holden HD 179ci engines (February 1965 – April 1966). Holden HD
(February 1965 – April 1966), HR and HK
(April 1966 – 1968), HT and
HG 186ci engines with
automatic transmissions.
Holden HD (February
1965 – April 1966) 179ci
engines, Holden HD 179ci X2
engines front carburettor (February
1965 – April 1966) and HR (April 1966 –
1967) X2 engines with
automatic transmissions
front carburettor
Holden HD (February
1965 – April 1966) 179ci, Holden HD 179ci X2
engines rear carburettor (February
1965 – April 1966) and HR (April
1966 – 1967) X2 engines
with automatic
transmissions rear
carburettor.
Holden HR and HK (April 1966-1968), HT, HG and LC 161ci engines with
manual transmissions.
Holden HR and HK (April 1966
– 1968), HT and HG 186ci engines with
manual transmissions.
HR 186ci X2 engines with
manual transmission
front carburettor
(April 1966 – 1967).
HR 186ci X2 engines with
manual transmission
rear carburettor
(April 1966 – 1967)
Holden HR, HK, HT and HG 186S
engines with manual
transmissions.
Holden HR, HK, HT and
HG 186S engines with
automatic transmissions.
Stamping 23-3013 and
23-3007
23-3008 and 23-
3014
23-3009 and 23-
3015
23-3010 and 23-
3016 23-3019 23-3020 23-3024
23-3023 23-201A and 23-201B
23-202, 23-202A and 23-202B
Model BXUV-2 BXV-2 BXUV-2 (NOTE 48) BXUV-2 BXV2 BXUV-2 (NOTE 52) WW (NOTE 52)
26
Specification 2375009 2375010 2375013 2375014 2375024 2375025 2375027 2375028 381205 381206 Flange size SAE 1¼ size cross flange with 2
11/16” bolt spacing Four-bolt
Main venturi diameter 1
3/32” 1
5/32” 1
3/32” 1
5/32” 1
3/32” 1
28/32”
Throttle bore diameter 1
5/16” 1
7/16” 1
5/16” 1
7/16” 1
5/16” 1
7/16”
Main metering jet
(NOTE 51)
0.055” (NOTE 6)
0.058” (NOTE
50) 0.055”
0.055” (NOTE
33)
0.058” (NOTE
34) 0.055” 0.055”
0.053” (NOTE 35)
Main discharge jet
(NOTE 8) (NOTE 51)
28-30 #36 drill
High speed bleeder #70 drill (0.0280”)
Idle tube #68 drill (0.0310”) #70 drill (0.0280”) #68 drill (0.0310”) #70 drill (0.0280”)
(NOTE 56) #70 drill (0.0280”)
(NOTE 36)
Idle air bleed #53 drill (0.0595”)
0.054” #53 drill (0.0595”)
(NOTE 37) #53 drill
(0.0595”) 0.054”
#53 drill (0.0595”) (NOTE 38)
#40 drill (main body – 0.0980”)
#50 drill (air horn – 0.0700”)
(NOTE 39)
Idle discharge holes
#56-64-70 drill (0.0465-0.0360-0.0280”)
#56-58 drill
(0.0465-0.0420”)
#56-64-70 drill (0.0465-0.0360-0.0280”)
#56-58 drill
(0.0465-0.0420”)
#56-64-70 drill (0.0465-0.0360-0.0280”)
#50-54 drill (0.0700-0.0550”)
(NOTE 40)
Idle screw setting 1 turn out 1.5 turns out
Power bypass jet
(NOTE 51)
#56 drill (0.0465”) (Note 59)
#55 drill (0.0520”)
#56 drill (0.0465”)
#56 drill (0.0465”) (NOTE
41)
#55 drill (0.0520”)
#56 drill (0.0465”) #56 drill (0.0465”)
(NOTE 42)
Pump bypass jet #56 drill (0.0465”) -
Pump discharge jet
(NOTE 51) #72 drill (0.0250”)
#68 drill nozzle (0.0310”) (NOTE 43)
Pump capacity per
stroke 0.5-0.8cc -
Float needle seat orifice diameter
(NOTE 26)
0.073” 0.092”
(NOTE 49) 0.092” 0.073” 0.092” (NOTE 53) 0.101”
Float bench setting
1/8”
3/16”
Fuel level at 3psi
(NOTE 28)
5/8-
11/16”
5/8”@3¼ psi
27
Pump link setting Middle
Pump stroke – bench setting
7/32-
19/64”
7/32-
19/64”
7/32-
19/64”
- Pump stroke – vehicle setting
(NOTE 29)
5/32-
15/64”
(NOTE 46)
3/16-
17/64”
(NOTE 46)
5/32-
15/64”
(NOTE 46)
5/32-
15/64”
(NOTE 54)
3/16-
17/64”
(NOTE 54)
5/32-
15/64”
(NOTE 54)
Vent valve lift (NOTE 32) 0.040-0.060” (NOTE 47) 0.040-0.060” (NOTE 55) Wide open kick setting
-
9/32”
Vacuum kick setting
7/32”
Thermostat adjustment #69 Dead Centre
Dashpot setting
1/16-
3/32”
Fast idle speed and
cam position setting
#15 drill (0.1800”), 37/8
turn
Accelerator pump stroke and external vent setting
+/-0.015”
Choke modulation
spring setting +/-0.010”
Thermostat lever position
setting 1
3/32”
NOTE 1: The Master Parts Catalogue (20 Years of Holden Production) lists the different Specifications as Carburettor Assemblies. The split of
which Specification (Assembly) goes to which vehicle is slightly different to the Stromberg Carburettor Service Manual No. BM1
issued August 1968 and the Bendix Corporation Australia (Automotive) Pty Ltd Carburettor & Fuel Pump Service Parts Catalogue No.
PC2 Issued March 1968 values used in the first row of the table above. The Specifications (Assemblies) listed in the Master Parts
Catalogue (20 Years of Holden Production) which conflict with the above are as follows:
Carburettor assembly 48, 50, FJ 7402765
Carburettor assembly FE, FC, FB, EK (manual), EJ (manual) 7412264
Carburettor assembly EK (automatic), EJ (automatic) 7418661
Carburettor assembly EH 149 engine, HD 149 engine, HR (automatic) 161 engine 7426784
Carburettor assembly EH 179 engine, HD 179 (excluding X2) engine, HR (automatic) 186
(excluding X2 and S) engine 7426904
Carburettor assembly HD 149 engine, HR 161 engine economy carburettors 7430100
Carburettor assembly HD 179 (excluding X2), HR 186 (excluding X2 and S) engine economy carburettors 7430107
Carburettor assembly - front HD X2 engine, HR (automatic) X2 engine 7428498
Carburettor assembly – rear HD X2 engine, HR (automatic) X2 engine 7428502
28
NOTE 2: The Master Parts Catalogue (20 Years of Holden Production) lists both 0.050” and 0.051” main metering jets for 48, 50 and FJ
Holdens. The Scientific Publications Workshop Manual Series No. 67 Holden covering series 1948/‟53 FJ, FE, FC, FB, EK, EJ, EH,
HD, HR lists a 0.050” main metering jet for 1948/53 Holdens. The Holden FJ Workshop Manual lists a 0.051” main metering jet for all
FJ Holdens.
NOTE 3: The Holden „EJ‟ „EH‟ Workshop Manual lists 0.057” main metering jets for EH Holden 149ci engines. The Master Parts Catalogue (20
Years of Holden Production) lists 0.051”, 0.053” and 0.055” main metering jets for EH Holden 149ci engines.
NOTE 4: The Holden „EJ‟ „EH‟ Workshop Manual lists 0.058” main metering jets for EH Holden 179ci engines, as does the Scientific
Publications Workshop Manual Series No. 67 Holden covering series 1948/‟53 FJ, FE, FC, FB, EK, EJ, EH, HD, HR.
NOTE 5: The Master Parts Catalogue (20 Years of Holden Production) lists 0.055”, 0.057”, 0.058” and 0.059” main metering jets for EH Holden
179ci engines.
NOTE 6: The Holden Workshop Manual (48/215 Manual) indicates that three combinations of main metering jets were used in production:-
“A” – early production, distinguished by one red paint dot on the float chamber cover (0.050”),
“B” – intermediate production, distinguished by two green paint dots on the float chamber cover (0.050”), and
“C” – late production, no distinguishing marks (No. 0.051”).
Individual parts of early, intermediate or late production jet combinations must not be mixed. The carburettor repair kit serviced by
“NASCO” contains a complete jet combination and this kit must be used to service all carburettors. When carburettors are services
and the setting is changed, the distinguishing marks on the top of the float chamber cover must be altered to agree with the
specifications above.
The Master Parts Catalogue (20 Years of Holden Production) lists 0.055” main metering jets for HD Holden 149ci (non-economy)
engines, as does the Scientific Publications Workshop Manual Series No. 67 Holden covering series 1948/‟53 FJ, FE, FC, FB, EK,
EJ, EH, HD, HR. The Holden HD Workshop Manual lists a 0.055” main metering jets for all HD Holden 149ci engines, with a 0.053”
main metering jet for 4,000-8,000ft and a 0.051” main metering jet for 8,000-12,000ft high altitude operation.
NOTE 7: The Master Parts Catalogue (20 Years of Holden Production) lists 0.058” and 0.059” main metering jets for HD Holden 179ci
(excluding X2) non-economy engines. The Scientific Publications Workshop Manual Series No. 67 Holden covering series 1948/‟53
FJ, FE, FC, FB, EK, EJ, EH, HD, HR lists a 0.058” main metering jet for all HD Holden 179ci and HR Holden 186ci engines.
NOTE 8: I have listed in the table the values for main discharge jet numbers given in the Holden EK Workshop Manual, the Holden „FB‟
Workshop Manual, The Holden „EJ‟ „EH‟ Workshop Manual, the Scientific Publications Workshop Manual Series No. 67 Holden
covering series 1948/‟53 FJ, FE, FC, FB, EK, EJ, EH, HD, HR and the Scientific Publications Workshop Manual Series No. 86 Holden
covering series HK, HT, HG. The Bendix Corporation Australia (Automotive) Pty Ltd Carburettor & Fuel Pump Service Parts
Catalogue No. PC2 Issued March 1968) indicates a single main discharge jet for all these carburettors (not the multiple values given
above), but does not indicate its size. The Holden Workshop Manual (48/215 Manual) indicates that three combinations of main
discharge jets were used in production:-
“A” – early production, distinguished by one red paint dot on the float chamber cover (No. 28-34),
“B” – intermediate production, distinguished by two green paint dots on the float chamber cover (No. 28-30), and
“C” – late production, no distinguishing marks (No. 28-30).
29
Individual parts of early, intermediate or late production jet combinations must not be mixed. The carburettor repair kit serviced by
“NASCO” contains a complete jet combination and this kit must be used to service all carburettors. When carburettors are services
and the setting is changed, the distinguishing marks on the top of the float chamber cover must be altered to agree with the
specifications above.
NOTE 9: The Master Parts Catalogue (20 Years of Holden Production) lists all EH Holdens as having a 28-30 main discharge jet, as does the
Scientific Publications Workshop Manual Series No. 67 Holden covering series 1948/‟53 FJ, FE, FC, FB, EK, EJ, EH, HD, HR.
NOTE 10: The Holden „EJ‟ „EH‟ Workshop Manual lists a Nº.68 drill (0.0310”) high speed bleeder for EH Holden 179ci engines.
NOTE 11: The Holden „EJ‟ „EH‟ Workshop Manual lists a Nº.70 drill (0.0280”) idle tube for EH Holden 149ci engines. The Scientific Publications
Workshop Manual Series No. 67 Holden covering series 1948/‟53 FJ, FE, FC, FB, EK, EJ, EH, HD, HR lists a Nº.68 drill (0.0310”) for
all EH Holden engines.
NOTE 12: The Bendix Corporation Australia (Automotive) Pty Ltd Carburettor & Fuel Pump Service Parts Catalogue No. PC2 Issued March
1968 indicates a Nº.70 drill (0.0280”) idle tube for Holden EH 149ci engines with manual and automatic transmissions (early 1964 -
February 1965), with a Nº.68 drill (0.0310) used from August 1964. The Holden „EJ‟ „EH‟ Workshop Manual lists a Nº.70 drill
(0.0280”) idle tube for EH Holden 149ci engines.
NOTE 13: The Bendix Corporation Australia (Automotive) Pty Ltd Carburettor & Fuel Pump Service Parts Catalogue No. PC2 Issued March
1968 indicates a Nº.70 drill (0.0280”) idle tube for Holden EH 179ci engines with manual and automatic transmissions (early 1964 –
February 1965). The Holden „EJ‟ „EH‟ Workshop Manual lists a Nº.70 drill (0.0280”) idle tube for EH Holden 179ci engines.
NOTE 14: The Scientific Publications Workshop Manual Series No. 67 Holden covering series 1948/‟53 FJ, FE, FC, FB, EK, EJ, EH, HD, HR
lists a Nº.68 drill (0.0310”) for all HD and HR Holden engines. The Holden HD Workshop Manual lists a Nº.68 drill (0.0310”) for all HD
Holden engines.
NOTE 15: The Bendix Corporation Australia (Automotive) Pty Ltd Carburettor & Fuel Pump Service Parts Catalogue No. PC2 Issued March
1968 indicates a Nº.70 drill (0.0280”) idle tube for Holden HD 179ci economy (taxi) engines (late 1965 – April 1966) and Holden HR
and HK 186ci economy (taxi) engines (April 1966 – 1968).
NOTE 16: The Scientific Publications Workshop Manual Series No. 67 Holden covering series 1948/‟53 FJ, FE, FC, FB, EK, EJ, EH, HD, HR
lists a Nº.53 drill (0.0310”) idle air bleed for all EH Holden 149ci engines.
NOTE 17: The Holden „EJ‟ „EH‟ Workshop Manual lists a Nº.52 drill (0.0635”) idle air bleed for EH Holden 149ci engines.
NOTE 18: The Holden „EJ‟ „EH‟ Workshop Manual lists a Nº.50 drill (0.070”) idle air bleed for EH Holden 179ci engines.
NOTE 19: The Scientific Publications Workshop Manual Series No. 67 Holden covering series 1948/‟53 FJ, FE, FC, FB, EK, EJ, EH, HD, HR
lists a Nº.53 drill (0.0595”) for all HD Holden 149ci and HR Holden 161ci engines.
NOTE 20: The Scientific Publications Workshop Manual Series No. 67 Holden covering series 1948/‟53 FJ, FE, FC, FB, EK, EJ, EH, HD, HR
lists a 0.054” idle air bleed for all HD Holden 179ci and HR Holden 186ci engines (excluding X2 engines).
NOTE 21: The Master Parts Catalogue (20 Years of Holden Production) indicates that 48/50/FJ/FE/FC/FB/EK/EJ all share same power bypass
jet assembly but does not list the size. The Scientific Publications Workshop Manual Series No. 67 Holden covering series 1948/‟53
FJ, FE, FC, FB, EK, EJ, EH, HD, HR lists a Nº.63 drill power bypass jet (0.0370”) for 1948/53 Holdens, Nº.67 drill (0.0320”) for FJ,
FE and FC Holdens and a Nº.65 drill (0.0350”) for FB, EK and EJ Holdens. The Holden FE and FC Workshop Manual lists a Nº.67
30
drill (0.0320”) power bypass jet for all FE and FC Holdens. The Holden FJ Workshop Manual lists a No. 67 drill (0.0320”) power
bypass jet for all FJ Holdens.
NOTE 22: The Holden „EJ‟ „EH‟ Workshop Manual lists a Nº.57 drill (0.0430”) power bypass jet for EH Holden 149ci engines. The Master Parts
Catalogue (20 Years of Holden Production) lists both a Nº.57 drill (0.0430”) and Nº.56 drill (0.0465”) power bypass jets for EH Holden
149ci engines.
NOTE 23: The Holden „EJ‟ „EH‟ Workshop Manual lists a Nº.54 drill (0.0550”) power bypass jet for EH Holden 179ci engines. The Master Parts
Catalogue (20 Years of Holden Production) lists both Nº.55 drill (0.0520”) and Nº.54 drill (0.0550”) power bypass jets for EH Holden
179ci engines.
NOTE 24: The Master Parts Catalogue (20 Years of Holden Production) lists a Nº.56 drill (0.0465”) power bypass jet for HD Holden 149ci non-
economy engines and a Nº.65 drill (0.0350”) for economy engines. The Scientific Publications Workshop Manual Series No. 67
Holden covering series 1948/‟53 FJ, FE, FC, FB, EK, EJ, EH, HD, HR lists a Nº.56 drill (0.0465”) power bypass jet for all HD Holden
149ci and HR Holden 161ci engines. The Holden HD Workshop Manual lists a Nº.56 drill (0.0465”) power bypass jet for all HD
Holden 149ci engines
NOTE 25: The Master Parts Catalogue (20 Years of Holden Production) lists a Nº.65 drill (0.0350”) power bypass jet for non-economy HD
Holden 179ci and non-economy HR Holden 186ci engines and a Nº.56 drill (0.0465”) for the economy versions of both engines. The
Scientific Publications Workshop Manual Series No. 67 Holden covering series 1948/‟53 FJ, FE, FC, FB, EK, EJ, EH, HD, HR lists a
Nº.55 drill (0.0520”) power bypass jet for all HD Holden 179ci and HR Holden 186ci engines.
NOTE 26: The Master Parts Catalogue (20 Years of Holden Production) lists float needle valve and seat assemblies which imply different sizes
for some vehicle to those specified in the Holden EK Workshop Manual, Holden „FB‟ Workshop Manual and Holden „EJ‟ „EH‟
Workshop Manual values used in the table above. The float needle valve and seat assemblies specified in the Master Parts
Catalogue (20 Years of Holden Production) are as follows:
Float needle valve and seat assembly 48, 50, FJ 7405155
Float needle valve and seat assembly FE, FC, FB, EK, EJ, EH, HD, HR (excluding S engine) 7406701
Float needle valve and seat assembly – heavy duty FE, FC, FB, EK, EJ, EH, HD, HR (excluding S engine) 7420335
Float needle valve and seat assembly HR S engine VS10443
The Bendix Corporation Australia (Automotive) Pty Ltd Carburettor & Fuel Pump Service Parts Catalogue No. PC2 Issued March
1968 indicates a 0.073” float needle and seat diameter (with an optional 0.079” heavy duty unit) for all the above vehicles with the
exception of Holden 48, 50, FJ, FE, FE and early FC (1948-1959), which it lists as 0.070”.
NOTE 27: The Holden FB, Holden EK and Holden „EJ‟ „EH‟ Workshop Manuals list 0.073” for these cars, as does the Scientific Publications
Workshop Manual Series No. 67 Holden covering series 1948/‟53 FJ, FE, FC, FB, EK, EJ, EH, HD, HR (it also lists 0.070” for late FC
Holden).The Holden FE and FC Workshop Manual lists a 0.070” orifice.
NOTE 28: The Stromberg Carburettor Service Manual No. BM1 issued August 1968 indicates fuel level at 3psi for B-series and 3¼ psi for WW
models, and are the values tabulated above. The Holden Workshop Manual (48/215 Manual), Holden FJ Workshop Manual, Holden
FE and FC Workshop Manual, Holden EK Workshop Manual, Holden FB Workshop Manual and „EJ‟ „EH‟ Workshop Manual (EJ
motor section) both lists the same values at 4psi. The „EJ‟ „EH‟ Workshop Manual (EH motor section) lists the fuel level for 179ci
31
engines as 43
/64-11
/16” at 3psi. The Scientific Publications Workshop Manual Series No. 67 Holden covering series 1948/‟53 FJ, FE,
FC, FB, EK, EJ, EH, HD, HR gives the single value of 5/8” at idling.
NOTE 29: I have given the values for accelerator pump stroke from the Stromberg Carburettor Service Manual No. BM1 issued August 1968.
The Scientific Publications Workshop Manual Series No. 67 Holden covering series 1948/‟53 FJ, FE, FC, FB, EK, EJ, EH, HD, HR
gives the following values:
1948/53 Holden 0.297” maximum
FJ/FE/FC Holden 0.281” +0.015” -0.024”
FB/EK/EJ Holden 0.281” +0.015” – 0.024”
EH/HD/HR Holdens 0.250” +/-0.030”
NOTE 30: The Holden „EJ‟ „EH‟ Workshop Manual indicates a pump stroke setting of 3/16-
7/32” for EH Holden 149ci engines.
NOTE 31: The Holden „EJ‟ „EH‟ Workshop Manual indicates a pump stroke setting of 3/16-
7/32” for EH Holden 179ci engines.
NOTE 32: I have given the values for the vent valve settings from the Stromberg Carburettor Service Manual No. BM1 issued August 1968. The
Scientific Publications Workshop Manual Series No. 67 Holden covering series 1948/‟53 FJ, FE, FC, FB, EK, EJ, EH, HD, HR lists
EH/HD/HR Holdens as 0.55” +/-0.005”.
NOTE 33: The Master Parts Catalogue (20 Years of Holden Production) lists 0.053” main metering jets for 4,000-8,000ft and 0.051” for 8,000-
12,000ft high altitude operation of HR Holden 161ci engines, and 0.051” main metering jets for HR Holden 161ci economy engines.
The Bendix Corporation Australia (Automotive) Pty Ltd Carburettor & Fuel Pump Service Parts Catalogue No. PC2 Issued March
1968 indicates a 0.055” main metering jet for Holden HR and HK (April 1966-1968), HT, HG and LC 161ci engines with manual
transmissions, with a 0.053” main metering jet for 4,000-8,000ft and 0.051” main metering jet for 8,000-12,000ft high altitude
operation, as does the Holden HR Workshop Manual for all HR Holden 161ci engines.
NOTE 34: The Bendix Corporation Australia (Automotive) Pty Ltd Carburettor & Fuel Pump Service Parts Catalogue No. PC2 Issued March
1968 indicates a 0.058” main metering jet for Holden HR and HK (April 1966 – 1968), HT and HG 186ci engines with manual
transmissions, with a 0.057” main metering jet for 4,000-8,000ft and 0.055” main metering jet for 8,000-12,000ft high altitude
operation, as does the Holden HR Workshop Manual for all HR Holden 186ci engines.
NOTE 35: The Master Parts Catalogue (20 Years of Holden Production) lists 0.051” main metering jets for 4,000-8,000ft and 0.049” for 8,000-
12,000ft high altitude operation of HR Holden 186ci (186S) engines. The Scientific Publications Workshop Manual Series No. 67
Holden covering series 1948/‟53 FJ, FE, FC, FB, EK, EJ, EH, HD, HR lists a 0.058” main metering jet for all HR 186ci engines. The
Bendix Corporation Australia (Automotive) Pty Ltd Carburettor & Fuel Pump Service Parts Catalogue No. PC2 Issued March 1968
indicates a 0.056” jet for Holden HR, HK, HT and HG 186S engines.
NOTE 36: The Scientific Publications Workshop Manual Series No. 67 Holden covering series 1948/‟53 FJ, FE, FC, FB, EK, EJ, EH, HD, HR
lists a Nº.68 drill (0.0310”) for all HR Holden engines.
NOTE 37: The Master Parts Catalogue (20 Years of Holden Production) lists a Nº.52 drill (0.0635”) idle air bleed for HD and HR Holden X2
engines, as does the Scientific Publications Workshop Manual Series No. 67 Holden covering series 1948/‟53 FJ, FE, FC, FB, EK,
EJ, EH, HD, HR.
32
NOTE 38: The Scientific Publications Workshop Manual Series No. 67 Holden covering series 1948/‟53 FJ, FE, FC, FB, EK, EJ, EH, HD, HR
lists a Nº.52 drill idle air bleed for all HR X2 engines.
NOTE 39: The Scientific Publications Workshop Manual Series No. 67 Holden covering series 1948/‟53 FJ, FE, FC, FB, EK, EJ, EH, HD, HR
lists a single 0.054” idle air bleed for all HR Holden 186ci engines.
NOTE 40: The Scientific Publications Workshop Manual Series No. 86 Holden covering series HK, HT, HG indicates Nº.46-57-63 drill (0.0810-
0.0430-0.0370”) idle discharge holes for 186S engines (the HR, HK, HT and HG Holden 186S engines have identical WW Stromberg
carburettors).
NOTE 41: The Master Parts Catalogue (20 Years of Holden Production) lists a Nº.65 drill (0.0350”) power bypass jet for HR Holden 161ci
economy engines.
NOTE 42: The Scientific Publications Workshop Manual Series No. 67 Holden covering series 1948/‟53 FJ, FE, FC, FB, EK, EJ, EH, HD, HR
lists a Nº.55 drill (0.0520”) power bypass jet for all HR Holden 186ci engines.
NOTE 43: The Scientific Publications Workshop Manual Series No. 67 Holden covering series 1948/‟53 FJ, FE, FC, FB, EK, EJ, EH, HD, HR
lists a Nº.72 drill (0.0250”) pump discharge jet for all HR Holden 186ci engines.
NOTE 44: The Holden HD Workshop Manual lists all Holden 179ci engines as having been fitted with the BXV-2 carburettor.
NOTE 45: The Holden HD Workshop Manual lists all HD Holden BXUV-2 carburettors as having a 13/32” main venturi diameter.
NOTE 46: The Holden HD Workshop Manual indicates a pump stroke setting of 7/32-
9/32” for all HD Holden engines.
NOTE 47: The Holden HD Workshop Manual indicates an idle vent valve lift setting of 0.050-0.060” for all HD Holden engines.
NOTE 48: The Holden HD Workshop Manual indicates a BXV-2 carburettor for all HD Holden 179ci engines.
NOTE 49: The Holden HD Workshop Manual indicates a 0.073” float needle seat orifice for all HD Holden 179ci engines.
NOTE 50: The Holden HD Workshop Manual lists a 0.058” main metering jets for all HD Holden 179ci engines, with a 0.057” main metering jet
for 4,000-8,000ft and a 0.055” main metering jet for 8,000-12,000ft high altitude operation.
NOTE 51: The Holden HD Workshop Manual indicates that these jets are subject to variation by the carburettor manufacturer to meet Holden
Flow Curve requirements, as does the Holden HR Workshop Manual.
NOTE 52: The Holden HR Workshop Manual lists all Holden 186ci engines as having been fitted with the BXV-2 carburettor.
NOTE 53: The Holden HR Workshop Manual lists all HR Holdens as having a 0.073” diameter float needle seat orifice.
NOTE 54: The Holden HR Workshop Manual lists all HR Holdens as having a pump stroke vehicle setting on 7/32”-
9/32”.
NOTE 55: The Holden HR Workshop Manual lists all HR Holdens as having a vent valve setting of 0.050-0.060”.
NOTE 56: The Holden HR Workshop Manual lists all HR Holdens as having a No. 68 drill (0.0310”) idle tube.
NOTE 57: The Holden FE and FC Workshop Manual lists a No. 28-30 main discharge jet for all FE and FC Holdens. The Holden FJ Workshop
Manual lists a No. 28-30 main discharge jet for all FJ Holdens.
NOTE 58: The Holden FJ Workshop Manual indicates a pump stroke vehicle setting of 17
/64-19
/64” for all FJ Holdens, as does the Holden FE and
FC Workshop Manual, Holden FB Workshop Manual and Holden EK Workshop Manual for all FJ, FE and FC, FB and EK Holdens.
NOTE 59: The Holden Workshop Manual (48/215 Manual) indicates that three combinations of power bypass jets were used in production:-
“A” – early production, distinguished by one red paint dot on the float chamber cover (No. 63 drill, 0.037”),
“B” – intermediate production, distinguished by two green paint dots on the float chamber cover (No. 66 drill, 0.033”), and
33
“C” – late production, no distinguishing marks (No. 67 drill, 0.032”).
Individual parts of early, intermediate or late production jet combinations must not be mixed. The carburettor repair kit serviced by
“NASCO” contains a complete jet combination and this kit must be used to service all carburettors. When carburettors are services
and the setting is changed, the distinguishing marks on the top of the float chamber cover must be altered to agree with the
specifications above.
5.1 EH Holden S4 Carburettor
The EH Holden S4 was Holden‟s first approach to a purpose-built race vehicle, and preceeded the twin-carburettored HD and HR Holdens. The
EH Holden S4 BXV-2 carburettor had a number of changes compared to the standard 179ci EH Holden motor:
the vacuum power piston was changed as described in Section 6.2 below.
the main metering jet was changed from 0.059" to 0.058".
the idle tube was changed from #70 drill (0.0280") to #68 drill (0.0310").
The vacuum power piston change is described as the only S4-specific carburettor change in the S4 supplement to the EH Holden Workshop
Manual. The main metering jet and idle tube changes are noted in the Bendix Corporation Australia (Automotive) Pty Ltd Carburettor & Fuel Pump
Service Parts Catalogue No. PC2 Issued March 1968. These changes were first introduced for the S4, but later carried through for all subsequent
EH Holden 179ci engines.
Page 34 of 148
6 Assembly Diagrams
The following assembly diagrams relate to early Holden Stromberg carburettors.
6.1 BXOV-1 Assembly Diagram
The following diagram shows the assembly of the Stromberg BXOV-1 carburettor. I have drawn this from
the Holden Workshop manuals – note that the numbering is different from that in The Bendix Corporation
Australia (Automotive) Pty Ltd Carburettor and Fuel Pump Service Parts Catalogue No. PC2 issued
March 1968, though the diagram is identical. Nº. DESCRIPTION
1 Choke shaft and control lever assembly
2 Choke valve attaching screw
3 Choke wire clamp screw
4 Manual choke lever spring
5 Choke tube clamp screw
6 Manual choke lever assembly (includes 3)
7 Choke tube holder assembly (includes 5, 8 and 9)
8 Choke tube clamp screw lockwasher
9 Choke screw clamp screw nut
10 Choke tube holder attaching screw and lockwasher
10a Air horn attaching screw and lockwasher
11 Choke valve assembly
12 Fast idle lever
13 Fast idle lever attaching nut
14 Fast idle lever attaching nut lockwasher
15 Lead ball plug
16 Air horn assembly
17 Air horn gasket
18 Fast idle rod
19 Vacuum power piston assembly
20 Idle tube assembly
21 Power bypass jet assembly
22 Pump and power bypass jet gasket
23 Pump stem cotter pin
24 Pump rod
25 Pump stem spring
26 Pump piston and stem assembly
27 Pump bypass jet assembly
28 Pump strainer screen clip
29 Pump strainer screen
30 Float fulcrum pin spring
31 Float and lever assembly
32 Float fulcrum pin
33 Main body and throttle body drive plug
34 Main body attaching screw and lockwasher
35 Float needle and seat assembly (includes 36)
36 Float needle and seat gasket
37 Main body assembly
38 Pump check valve assembly
39 Check valve plug gasket
40 Pump check valve plug
41 Main discharge jet
42 Main metering jet
43 Metering jet plug gasket
44 Main metering jet plug
45 Main body gasket
46 Main body insulating spacer
47 Throttle lever and shaft assembly
48 Throttle valve attaching screw
49 Pump link spring clip
50 Pump link
51 Pump lever
52 Pump lever attaching nut lockwasher
53 Pump lever attaching nut
54 Slow idle adjusting screw
55 Slow idle adjusting screw spring
56 Fast idle cam
57 Fast idle cam lever
58 Fast idle cam lever cotter pin
59 Idle needle valve
60 Idle needle valve spring
61 Throttle valve
62 Throttle body assembly
Page 35 of 148
6.2 BXUV-2/BXV-2 Assembly Diagram
The following diagram shows the assembly of the Stromberg BXUV-2 and BXV-2 carburettors. I have
drawn this from the Holden Workshop manuals – note that the numbering is different from that in The
Bendix Corporation Australia (Automotive) Pty Ltd Carburettor and Fuel Pump Service Parts Catalogue
No. PC2 issued March 1968 (and the BXOV-1 diagram above). Nº. DESCRIPTION
1 Choke shaft and control lever assembly
2 Choke valve attaching screw
3 Choke wire clamp screw
4 Manual choke lever spring
5 Choke tube clamp screw
6 Manual choke lever assembly (includes 3)
7 Choke tube holder assembly (includes 5, 8 and 9)
8 Choke tube clamp screw lockwasher
9 Choke screw clamp screw nut
10 Choke tube holder attaching screw and lockwasher
11 Choke valve assembly
12 Fast idle lever
13 Fast idle lever attaching nut
14 Fast idle lever attaching nut lockwasher
15 Vent valve locknut
16 Vent valve
17 Lead ball plug
18 Air horn attaching screw and lockwasher
19 Air horn assembly
20 Air horn gasket
21 Reinforcing bar
22 Vent valve spring
23 Vent valve stem
24 Pump stem cotter pin
25 Pump rod
26 Pump stem spring
27 Pump piston and stem assembly
28 Fast idle rod
29 Vacuum power piston assembly
30 Idle tube assembly
31 Power bypass jet assembly
32 Pump and power bypass jet gasket
33 Pump bypass jet assembly
34 Pump strainer screen clip
35 Pump strainer screen
36 Float fulcrum pin spring
37 Float and lever assembly
38 Float fulcrum pin
39 Main body assembly
40 Pump check valve assembly
41 Check valve plug gasket
42 Pump check valve plug
43 Main discharge jet
44 Main metering jet
45 Metering jet plug gasket
46 Main metering jet plug
47 Pump lever attaching nut lockwasher
48 Pump lever attaching nut
49 Pump lever
50 Pump link
51 Pump link spring clip
52 Main body and throttle body drive plug
53 Main body attaching screw and lockwasher
54 Restrictor wire
55 Float needle and seat assembly (includes 56)
56 Float needle and seat gasket
57 Main body gasket
58 Main body insulating spacer
59 Throttle valve attaching screw
60 Throttle shaft
61 Throttle lever
62 Throttle actuating lever
63 Throttle actuating lever lockwasher 64 Throttle lever attaching nut
65 Slow idle adjusting screw 66 Slow idle adjusting screw spring
67 Fast idle cam 68 Fast idle cam lever
69 Fast idle cam lever cotter pin 70 Idle needle valve
71 Idle needle valve spring 72 Throttle valve
73 Throttle body assembly
Page 36 of 148
The BXUV-2 and BXV-2 carburettor assemblies are very similar to the BXOV-1 diagram given above, with
the following changes:
Volume Restrictor Rod (Restrictor Wire)
From EH through HR Holdens, the Stromberg BXUV-2 and
BXV-2 carburettors were fitted with volume restrictor rods
(sometimes referred to as restrictor wires). The WW
carburettor used on HR 186S engines also had a similar rod.
The rods are inserted into the vertical idling passage in the
lower face of the main body assembly (after separating the
main and throttle bodies). The purpose of the rod is to reduce
the cross-sectional area of the idle channel to provide a good
idle under extremely hot operating conditions.
Idle vent valve (Anti-percolator Valve)
From EH through HR Holdens, the Stromberg BXUV-2 and
BXV-2 carburettors were fitted with idle vent valves (sometimes
referred to as anti-percolator valves). The WW carburettor used
on HR 186S engines also had a similar valve, though of
different operation. The
BXUV-2 and BXV-2
valves consist of a seat
fitted into the top of the
air horn directly above
the accelerator pump
stem. The valve seat is fitted with a valve stem and spring from
underneath, then a valve “washer” is screwed on from above. The
gap between the “washer” face and seat is adjusted at idle to the
settings tabulated below, taking care that the choke is off. The
“washer” is then locked into position with a locknut. The aim of the
idle vent valve is to vent buildup of vapours that form in the float
chamber during idle under hot conditions, as this type of
percolation (fuel boiling) in the fuel discharge system can cause
poor idle and hard hot-starting. At idle, the accelerator pump stem
rises upwards, and opens the valve. When moving away from idle,
the accelerator pump stem drops downwards, allowing the idle vent
valve to close. Note that whilst early Holdens vent the fuel bowl to
atmosphere, later model cars tend to vent the fuel bowl through a
carbon canister to minimize emissions.
Reinforcement bar
From EH through HR Holdens, the Stromberg BXUV-2 and BXV-2 carburettors
were fitted with air horn reinforcement bars. The bars are a simple piece of bent
steel, fitted to the top front edge of the air horn by the
two outer attaching screws. The reinforcing bar
provides a more positive seating of the air horn to the
main body. Australian Stromberg Code numbers were
often stamped on the reinforcing bars.
Page 37 of 148
Vacuum Power Piston Assembly
From mid-1964 onwards (during production of EH Holdens), the BX-Model main body was modified to
allow the vacuum power piston assembly to be placed in a lower position. This lead to the use of different
(longer) vacuum power pistons – 48-mid EH Holdens use a 25/32” overall length piston, whilst mid-EH
Holden onwards use a 29/16” piston. The pistons are not interchangeable. The diagram below indicates
the changes to the main bodies and piston assemblies.
Flange Bolt Spacing
The bolt spacing for the BXOV-1 carburettor (23/8”) is different from that of the BXUV-2
and BXV-2 carburettors (211
/16”).
Pump Lever
The pump lever for the BXOV-1 carburettor is different from that of the BXUV-1 and BXV-2
carburettors. The slot through which the throttle shaft mounts is the same width, though the
length (the dimension highlighted in the diagram to the right) is 7/32” for the BXOV-1 and
~17
/64” for the BXUV-2 and BXV-2 carburettors (this is because the BXOV-1 throttle shaft thread diameter
is 0.215” and 0.150” across the flat for a 3/8”AF nut, whilst the larger BXUV-2 and BXV-2 is 0.258” across
the threads and 0.170” across the flats for a 7/16” AF nut). Whilst the BXUV-2 and BXV-2 pump lever will
fit on the BXOV-1 carburettor throttle shaft, the increased clearance leads to a sloppy accelerator pump
response.
Throttle Shaft
The throttle shafts for BXOV-1 carburettors have the throttle lever fitted and the end
of the throttle shaft peined over. The BXUV-2 and BXV-2 carburettors do not have
the throttle shaft peined – rather a separate nut and lockwasher is fitted. Whilst
minor, this has an impact when using BXOV-1 carburettors in twin carburettor format with W-clip linkages
– see Section 10.4 below.
Note that there are other significant differences between the BXOV-1, BXUV-2 and BXV-2 carburettors
(venturi size, throttle bore diameter, jetting etc) which are not as readily apparent in the carburettor
assembly, and which will be further explored below.
Page 38 of 148
7 Disassembly and Overhaul Process
The following process describes the process of removal, disassembly and overhaul (often referred to as
“putting a kit through”) for a Stromberg BXOV-1 carburettor. I have used the numbering from the Holden
Workshop manual diagrams given above.
7.1 Kit Contents and Pre-disassembly
The following numbers indicate the Fuelmiser carburettor overhaul kits available for Holden Stromberg
carburettors:
Vehicle Carburettor Model Fuelmiser Kit Nº.
Holden FX-HJ, LC-LH Torana BXOV-1, BXUV-2, BXV-2, BXUV-3
SSB-652
Holden HX-HZ, LX-UC Torana, BX SSB-655
Holden HR-HZ, LC, LH and LX Toranas, VB Commodore WW SSB-651
The BXOV-1 carburettor overhaul is primarily completed with a Fuelmiser kit, part number SSB-652. The
kit contains the following parts:
a) and b) two main body gaskets
(45),
c) and d) two main body gaskets
not used in the overhaul of
BXOV-1 carburettors (I suspect
these are for BXV carburettors),
e) and f) two flange gaskets (not
numbered above – see Note 1
below),
g) an air horn gasket (17),
h) a pump lever (51 – see Note 2
below),
i) a pump link (50),
j) a fast idle cam cotter pin (58),
and a fast idle rod cotterpin (not
numbered in the drawing above),
k) a pump stem cotter pin (23),
l) a pump piston and stem
assembly (26),
m) a pump link spring clip (49),
n) a float fulcrum pin spring (30),
o) a 0.076” diameter float needle valve seat assembly (35),
p) a float needle valve (35),
q) two plastic caps for blocking off vacuum lines (not used in the overhaul of BXOV-1 carburettors),
r) a metering jet plug gasket (43),
s) a check valve plug gasket (39),
t) a float needle valve and seat gasket (36),
u) a power bypass jet gasket (22) and a pump bypass jet gasket (22).
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The kit also contains a very basic assembly drawing and a leaflet describing how to condition the
accelerator pump plunger.
Note 1: The two gaskets supplied in the Fuelmiser SSB-652 kit (a) and b) in the photograph below are not
suitable for the overhaul of a BXOV-1 carburettor:
Gasket a) suits a No. 3 (S.A.E. size 1½”) flange with throttle barrel diameter of 1
11/16" and 2
15/16” bolt
spacing such as on the BXUV-3 carburettor fitted to VC Valiants, whilst
Gasket b) suits a No. 2 (S.A.E. size 1¼”) flange with throttle barrel diameter of 1
7/16” and 2
11/16” bolt
spacing such as on the BXUV-2 and BXV-2 carburettors.
The correct gasket to suit the BXOV-1 carburettor (c) in the photograph) is available from the
Carburettor Service Company.
The image in the middle below shows the correct gaskets sitting on the bottom of a BXOV-1 throttle body.
The image to the right shows gasket b) (the smaller of the two supplied in the kit). Note the large gap
between the gasket bore and the throttle body bore, and the misalignment of the flange bolt holes,
highlighting the need to buy the additional (correct) gasket.
.
Note 2: The Fuelmiser SSB-652 kit does not supply the correct pump lever
(51) for BXOV-1 carburettors. The pump lever for the BXOV-1 carburettor is
different from that of the BXUV-1 and BXV-2 carburettors. The slot through
which the throttle shaft mounts is the same width, though the length (the
dimension highlighted in the diagram to the right) is 7/32” for the BXOV-1 and
~17
/64” for the BXUV-2 and BXV-2 carburettors. Whilst the BXUV-1 and BXV-2 pump lever will fit on the
BXOV-1 carburettor throttle shaft, the increased clearance leads to a sloppy accelerator pump response.
The picture above shows the pump lever supplied in the Fuelmiser SSB-652 kit (upper image, suitable for
BXUV-2 and BXV-2 carburettors), together with the correct one (lower image) for BXOV-1 carburettors.
The correct BXOV-1 pump lever is again available from the Carburettor Service Company.
Note 3: Fuelmiser supply a separate accelerator pump system lost motion
prevention spring (part No. SBP-043 – see image to the right) which is not part of
the SSB-652 overhaul kit. The SBP-043 spring is an additional spring not originally
installed on factory Stromberg carburettors. Over time (the last half century…), the
throttle shaft bearing areas, the linkage to the pump rod and the pump rod guide
(part of main body) can wear. This can result in a delayed accelerator pump plunger
movement when you accelerate, giving some lag (or sluggish feeling). The
Fuelmiser accelerator pump system lost motion prevention spring adds some
tension to the accelerator pump system, taking out some of the slack from the worn parts. This can give
crisper acceleration. It is recommended that the Fuelmiser accelerator pump system lost motion
prevention spring be fitted during overhaul.
Page 40 of 148
Note 4: The Fuelmiser kit does not contain a new split pin for the throttle control upper rod.
Prior to disassembling the carburettor, it is worthwhile checking for worn throttle shaft bearing areas. To
do so, start the engine and leave it idling with the air cleaner in place. Spray some WD40 around the main
body where the throttle lever and shaft assembly (47) passes through either side of the throttle body
assembly (62), using the red squirty straw on the can of WD40 to get at the right area. Make sure there is
no grease or dirt around the area that could block the WD40 from getting to the throttle body. If the engine
revs pick up, then the throttle shaft bearing areas are worn (letting in WD40 under vacuum to fuel the
motor) and should be professionally rebushed during the rebuild.
7.2 Special Tools
The following tools can make the overhaul process significantly easier:
GMH tool 6A10 (Stromberg part No. 73605) is used for two purposes. One end of
the tool is used to remove and replace the vacuum power piston assembly. The
other end of the tool is used to bend the float arm to adjust the fuel level in the
carburettor. The tool may be replaced by a pair of circlip pliers (to remove the
vacuum power piston assembly) and a screwdriver and pair of pliers (to bend the
float arm).
GMH tool 6A11 (Stromberg part No. 73608) is used to remove the main discharge
jet from the carburettor main body. The tool has a fine conical thread which
enables it to be screwed into the hole in the base of the main discharge jet. The
threads of the tool grip the jet, allowing it to be pulled out. A No1. screw extractor
(suitable for 1/8-¼ “ or M5-M6 bolts) or N
o. 2 screw extractor
(suitable for ¼-5/16” or M6-M8 bolts) will also work for this task. If
the main discharge jet is very stuck, it may be necessary to use
a pulling fixture to remove it. This is further explained below.
GMH tool 6A12 (Stromberg part No. 73606) is a socket type wrench
used to remove and install the main metering jet. This is probably
the only “special tool” which is indispensable for overhauling
Stromberg carburettors. The tool is available aftermarket from
Rocket Industries and the Carburettor Service Company.
GMH tool 6A20 is an accelerator pump installer. It is used
when installing the accelerator pump piston in its bore in the
carburettor main body. The tool smoothes the bore transition so that the piston leather does not crease or
wrinkle. In operation the tool is installed into the piston bore, then the
pump piston is inserted into the bore of the tool. The pump piston must
be fully installed before the tool is removed. This tool is not necessary
for overhauling Stromberg carburettors – care during the piston
installing process eliminates the need for the tool.
Note that there is also a float level gauge (Stromberg part number
73725) which is used to set the float levels on Stromberg WW-Model
carburettors.
Page 41 of 148
One non-genuine tricky tool is a large flathead screwdriver with a home-made slot cut in the
centre of the blade. This allows you to pull out the power bypass jet and accelerator bypass
jet without crunching the centre pin assemblies. You can however get away with a normal
screwdriver though (and most people do).
7.3 Removing the Carburettor from the Vehicle
1. Remove the air cleaner wingnut, air cleaner lid and filter
element. Slacken off the slot-head bolt under the filter base
then remove the base.
2. Remove the split pin from the throttle control upper rod and disengage the rod
from the carburettor. Leave the rod hanging from the rest of the throttle linkage
assembly.
3. Disconnect the fuel line flare nut (½” AF) and vacuum line
flare nut (3/8” AF) from the carburettor.
4. Slacken off the choke tube clamp screw (5) and choke wire clamp screw (3).
Pull the choke cable out from choke tube holder assembly (7). Leave the choke
cable hanging from the firewall.
5. Remove the carburettor flange nuts (½” AF) and withdraw
the carburettor from the manifold. Note that there is a
Bakelite spacer under the carburettor. When removing the
spacer, take care to pull it up squarely and gently, as
flexing the spacer can cause them to crack. Cracked
spacers will cause a vacuum leak and poor running.
6. Give the outside of the carburettor assembly a clean with some kerosene on a rag to get rid of the
worst of the oil and dirt prior to disassembly.
7.4 Disassembling the Air Horn
1. With the carburettor on a bench, remove the cotter pin (not numbered in the
drawing above) from the lower end of the fast idle rod (18) then remove the
rod. Note that the carburettor in these photographs is missing the fast idle cam.
2. Undo the five flat-head air horn attaching screws and
lockwashers (10A) and the choke tube holder attaching
screw and lockwasher (10). Note that 10A and 10 are very
similar – 10 is slightly longer to allow for the thickness of
the choke tube holder. Lift off the air horn assembly (16)
Page 42 of 148
and air horn reinforcing bar (if fitted – the BXOV-1 carburetor in these photographs had been fitted
with an EH 149ci air horn reinforcing bar).
3. Unscrew the vacuum power piston assembly (19) from the
air horn assembly (16) using a pair of circlip pliers (or the
original GMH Tool 6A10) to engage the two drive slots.
4. Remove the 5/16” AF fast idle lever attaching nut (13), lockwasher (14) and lever
(12).
5. For BXUV-2 and BXV-2 carburettors, remove the idle vent valve locknut, then
unscrew the idle vent valve washer. Remove the idle vent valve stem and spring assembly.
The choke assembly (1, 2, 4 and 11) is a pain to remove as the choke valve attaching screws are staked.
For most overhauls, it is not necessary to remove the choke assembly. Equally, the lead ball plug (15) is
not removed for most overhauls.
7.5 Disassembling the Main Body
1. Remove the pump link spring clip (49) from the pump link
(50) and remove the link.
2. Remove the pump piston and stem assembly (26) from the main body assembly
(37). Note that the air horn gasket (17) will also come along as it is held in place
by the pump piston.
3. Holding the pump piston and stem assembly (26) in your hands, squeeze down
the pump rod (24) to compress the pump stem spring (25). Remove the p ump
stem cotterpin (23) then release the spring pressure. Remove the pump rod
(24), pump stem spring (25) and air horn gasket (17) from the pump piston and
stem assembly (26).
4. Using a large flat bladed screwdriver, unscrew and remove the pump bypass
jet assembly (27) and the associated gasket (22) from the main body (37).
5. Using a large flat bladed screwdriver, unscrew and remove the power bypass
jet assembly (21) and the associated gasket (22) from the main body (37).
Page 43 of 148
6. Using a flat bladed screwdriver , unscrew the idle tube assembly (20) from the
main body (37).
7. Using a 9/16” AF spanner, remove the float needle valve and seat assembly (35)
and its associated gasket (36) from the main body (37).
8. Insert a small screwdriver between the float fulcrum pin (32) and the main body
(37) and pry off the float fulcrum pin spring (30) with a
twisting motion. Hold your hand over the float chamber as
you are doing so to prevent the spring from flying off.
9. Remove the float fulcrum pin (32) and float and lever
assembly (31) from the main body (37).
10. Using a large flat bladed screwdriver,
remove the main metering jet plug (44).
Unscrew the main metering jet (42)
using a jet key (or GMH tool 6A12), and
remove both the jet and associated
gasket (43) with needle nosed pliers. Remove the main discharge jet using GMH tool 6A11 or a
screw extractor (see notes above). Note that the threads/marks formed in removing the main
discharge jet will not affect the metering characteristics of the jet, and it need not be discarded
unless otherwise damaged. If the main discharge jet is firmly stuck in place, it may be necessary to
use a pulling fixture to remove them – this is a process I have borrowed from Flathead Youngin from
the HAMB. To do this:
a) soak the stuck main discharge jet in WD40 or similar penetrant for several days.
b) a small tap is driven into the main discharge jet, aiming to drive as square as possible. The tap is
driven to form only around three good threads. I have not tried this on B-Model Strombergs, but
Stromberg 97‟s usually use a No. 5 or N
o. 6 tap.
c) back the tap out and screw in a bolt of the same size as the tap. Do this gently, as the main
discharge jet material is soft brass.
d) fit a washer onto the bolt, and wind on a nut (or wingnut) until it bottoms on the main metering jet
plug boss.
e) gently wind the nut down so that the bolt pulls out the main discharge jet.
The photos below show the process being undertaken on a Stromberg 97.
Page 44 of 148
11. Using a large flat bladed screwdriver, remove the pump
check valve plug (40), the pump check valve assembly (38)
and associated copper gasket (39).
The pump strainer screen (29) and associated clip (28) are a pain to remove (and almost impossible to
find parts for once you punch a hole in the screen or sproing the clip across the workshop at the speed of
light). For most overhauls, it is not necessary to remove them.
7.6 Disassembling the Throttle Body
1. Remove the main body attaching screws and lockwashers
(34). Separate the throttle body (62) from the main body
insulating spacer (46) and main body (37). Remove the
associated main body gaskets (45).
2. Unscrew and remove the idle needle valve (59) and associated spring (60).
3. Unbolt and remove the 3/8” AF pump lever attaching nut (53) and lockwasher
(52). Remove the pump lever (51).
4. Remove the fast idle cam lever cotter pin (58), the fast idle cam (56) and lever
(57).
5. Unscrew and remove the slow idle adjusting screw (54)
and spring (55).
6. Remove the 1/8” NPT vacuum line adapter (
7/16” AF).
The throttle lever and shaft assembly (47, 48, 61) is a pain to remove as the throttle valve attaching
screws are staked. For most overhauls, it is not necessary to remove the throttle assembly. Equally, the
main body and throttle body drive plugs (33) are not removed for most overhauls.
The photographs below illustrate some of the assemblies and vacuum passages inside the carburettor
assemblies:
Page 45 of 148
7.7 Cleaning and Inspection
1. Clean all parts in some petrol to remove most of the oil and dirt. Ensure good ventilation and no open
flames when washing parts with petrol (or any of the solvents below). An alternative is to use one of
the spray type “carburettor and throttle body cleaners” available from SuperCheap, Repco etc. Most
of the cleaners available are made for spraying down a carburettor throat with the engine running,
rather than detailed cleaning of a disassembled carburettor. They tend to be mainly solvent,
evaporate very quickly, and are this not much use for “soaking” parts. They are also not very suitable
for removing the carbon (“coke”) that builds up inside carburettors (what little they dissolve tends to
restick as the cleaner evaporates). From trying some of them, I personally believe these spray
cleaners are little (if any) better than using straight petrol for cleaning disassembled carburettors.
Many forums recommend the use of “dip” cleaners to soak parts in (for example Berrymans B9
Chem Dip, which has a number of solvents, cresols and sodium bichromate). Some hunting has
shown that “dip” cleaners are very hard to come by in Australia. One that is available is Yamalube
Carburettor Cleaner, though I have not tried it. Paint thinners also does a fair job of removing the
gunk.
2. Blow out all passages with compressed air in the opposite direction to normal flow. Pay particular
attention to the pump strainer screen (29) as it may trap dirt in normal service. Do not rod-out any
jets or passages with drills or wires unless absolutely necessary as it is likely to change their flow
characteristics.
3. Use a steel rule to check that the main body assembly (37) and air horn assembly (16) are flat where
they join. Similarly check the main body assembly (37) and main body insulating spacer (46) mating
surfaces and the main body insulating spacer (46) and throttle body assembly (62) mating surfaces.
Should any of these surfaces not be flat, professional milling (or replacement) may be required.
4. Check the upper and lower idle discharge holes in the throttle body assembly (62) to make sure they
have no carbon deposits.
5. Examine the idle needle valve (59). If it is ringed or grooved it must be replaced.
6. Inspect the main discharge jet (41) for burrs at the venturi end. Burrs may be carefully removed with
a file, taking care not to change the shape or angle of the jet.
7. Inspect the main metering jet (42), pump bypass jet assembly (27), power bypass jet assembly (21),
idle tube assembly (20) to ensure they are clean.
8. Check the float and lever assembly (31) for dents and punctures.
9. Check the vacuum power piston assembly (19) for deep scratches or scores on the piston surface.
Check that the piston is a free fit in its cylinder.
10. Check the operation of the valve in the power bypass jet assembly (21) by putting the threaded end
into your mouth and sucking. The valve should not pass any air until the valve stem is pushed in.
Leaking power bypass jet assemblies will cause the engine to run rich at cruise conditions. This can
be cured by running slightly leaner main metering jets, though replacing the leaking power bypass jet
assembly is a wiser choice.
11. Check the throttle lever and shaft assembly (47) where it passes through either side of the throttle
body assembly (62) for looseness. Worn assemblies should be professionally rebushed during the
rebuild. Check that the throttle valve (61) opens and closes correctly.
12. Check the choke shaft and control lever assembly (1) where it passes through either side of the air
horn assembly (16) for looseness. Check that the choke valve assembly (11) opens and closes
correctly. Check that the choke poppet valve (part of the choke valve assembly (11)) is clean and
free to move and seat.
Page 46 of 148
7.8 Assembly and Reinstallation
1. Install the idle needle valve (59) and idle needle valve spring (60) into the throttle body assembly
(62). Screw them in gently until they are all the way in (do not overtighten!), then back them out 7/8 of
a turn (1 turn for BXUV-2 and BXV-2 carburettors).
2. Install the fast idle cam (56) and fast idle cam lever (57) to the throttle body assembly (62), securing
them in place with the new fast idle cam cotter pin (58) supplied in the Fuelmiser kit.
3. Install the pump lever (51), pump lever attaching nut (53) and associated lockwasher (52). Take care
to use the separately supplied pump lever rather than the one from the Fuelmiser kit (see notes
above).
4. Reinstall the slow idle adjusting screw (54) and slow idle adjusting screw spring (55) into the throttle
lever and shaft assembly (47). Back off the slow idle adjusting screw (54) until the throttle valve
assembly (61) seats in the throttle body assembly (62).
5. Install the main discharge jet using GMH tool 6A11 or a screw extractor (see noted above). Ensure
the jet is correctly located in the main body – the mitered face of the jet must be parallel with the
direction of air flow.
6. Install the main metering jet (42) into the main body assembly (37), using a jet key (or GMH tool
6A12). Install a metering jet plug gasket (43) from the Fuelmiser kit, and fit the main metering jet plug
(44) with a flat bladed screwdriver.
7. Install the pump check valve assembly (38) into the main body assembly (37) using a flat bladed
screwdriver. Install a check valve plug gasket (39) from the Fuelmiser kit, and fit the pump check
valve plug (40).
8. Install the main body assembly (37) and main body insulating spacer (46) on the throttle body
assembly (62) using main body gaskets (45) from the Fuelmiser kit. Take care to select the right
gaskets from the Fuelmiser kit (lay them over the old ones to check) as the kit has two spare gaskets
which do not suit BXOV-1 carburettors.
9. Install the idle tube assembly (20) into the main body assembly (37) with a flat bladed screwdriver.
10. Install the power bypass jet assembly (21) into the main body assembly (37) using a
power bypass jet gasket (22) from the Fuelmiser kit. Note that the original Stromberg
gaskets were fibre, and that the Fuelmiser kit gaskets are alloy. Be careful as the
power bypass jet assembly (21) and the pump bypass jet assembly (27) are very
similar. The power bypass jet assembly (21) has a small stem which protrudes above the body of the
jet – see image on the left above. The pump bypass jet assembly (27) stem does not protrude above
the body of the jet – see image on the right above.
11. Install the pump bypass jet assembly (27) into the main body assembly (37) using a pump bypass jet
gasket (22) from the Fuelmiser kit. Note again that the original Stromberg gaskets were fibre, and
that the Fuelmiser kit gaskets are alloy.
12. Install the float fulcrum pin (32) in the float and lever assembly (31) hinge. Place the resultant
assembly into the float chamber so that the ends of the float fulcrum pin (32) fit into the grooves in
each side of the float chamber. Place the float fulcrum pin spring (30) from the Fuelmiser kit into the
grooves on each side of the float chamber and force the bowed part of the spring down to clip under
the projection on the side of the float chamber.
13. Assembly the float needle valve and seat assembly (35) from the Fuelmiser kit, and install it into the
main body assembly (37), using a float needle valve and seat gasket (36) from the Fuelmiser kit.
Note that the gasket in the Fuelmiser kit is alloy.
Page 47 of 148
14. The float level can now be bench-set. For steel-tipped float needle
valves, the float is held up by hand until the needle valve is firmly
closed on its seat. For viton-tipped float needle valves, the main body
assembly is turned upside down and the weight of the float used to
hold the needle valve firmly closed on its seat. In both cases, the
distance from the top centre of the float to the top surface of the main
body (without the gasket) is measured. Bend the float lever (either
with GMH Tool No. 6A10, or a screwdriver/pair of needle nose pliers) until this distance is 1/8”. When
adjusting the float tab, don't force the float needle into its seat as it may damage the seal. Note that
bench-setting the float level gives a good starting point, but must be checked again once the
carburettor is reassembled, installed and the engine running (see Section 8.1 below).
15. For BXOV-1 carburettors, snap the tip off the pump piston and stem assembly (26) supplied in the
Fuelmiser kit (as the BXOV-1 carburettor does not have an idle vent valve – the tip is left in place for
BXUV-2 and BXV-2 carburettors). To prevent possible engine flat spots or hesitation upon
acceleration, condition the pump plunger leather cup by inserting a screwdriver blade under the cup
(between the leather cup and the brass support), flaring the skirt outwards as the blade is revolved
around the main body. Two or three revolutions will render the leather soft and pliable. Reshape the
cup with your fingers. Soak the cup in fuel, then revolve the pump piston and stem assembly (26) as
it is inserted down into the pump well. Recheck for proper fit – light to medium drag should be felt as
the assembly is worked up and down pump well.
16. Fit the pump stem spring (25) on the pump piston and stem assembly (26).
17. Position the cone shaped lost motion prevention spring (Fuelmiser SBP043) over the pump stem
spring (25) and pump piston and stem assembly (26), with the larger coils facing downwards seating
on the casting above the pump well.
18. Position the air horn gasket (17) from the Fuelmiser kit on the main body assembly (37).
19. Insert the pump rod (24) into main body assembly (37), compressing both the installed springs until
the pump piston and stem assembly (26) stem protrudes through the hole in the pump rod (24)
allowing fitment of the pump stem cotter pin (23). A new pump stem cotter pin (23) is included in the
Fuelmiser kit.
20. Install the pump link (50) between the bottom of the pump rod (24) and the centre hole of the pump
lever (51). Spring the pump link spring clip (49) onto the pump link (50). A new pump link (50) and
pump link spring clip (49) are included in the Fuelmiser kit.
21. The accelerator pump stroke can now be bench set, which saves having to do it once the carburettor
is installed. Measure and record the distance from the top of the accelerator pump piston stem
assembly (26) to the top face of the main body assembly (37, with the gasket removed). Open the
throttle fully and again check and record the distance. The difference between the two
measurements (which is the accelerator pump stroke) should be 17
/64-19
/64” (note that BXUV-2 and
BXV-2 carburettors having varying settings for accelerator pump stroke bench setting – see table in
Section 5 above). If the difference is more or less than this range, the accelerator pump stroke can
be changed by bending the top horizontal portion of the accelerator pump rod (24). Two bends are
need for each adjustment to keep the hole in the pump rod parallel with the pump stem.
22. Install the fast idle lever (12), fast idle lever attaching nut (13) and associated lockwasher (14) to the
choke shaft and control lever assembly (1).
23. Install the vacuum power piston assembly (10) into the air horn assembly (16) and tighten it with
circlip pliers (or GMH tool 6A10). Check the piston for free movement in the cylinder. Do not lubricate
the piston.
24. For BXUV-2 and BXV-2 carburettors, install the idle vent valve stem and spring assembly from
underneath the air horn. Fit the idle vent valve washer and locknut, leaving them loose for now. Note
Page 48 of 148
that the idle vent valve is set only once the carburettor is reassembled, installed, the engine running,
the idle has been set and the accelerator pump stroke checked (see Section 8.4 below).
25. Install the air horn assembly (16) onto the main body assembly (37). Install the five air horn attaching
screw and lockwashers (10A), being careful to put the longer choke holder attaching screw and
lockwasher (10) onto the correct corner together with the choke tube holder assembly (7). Tighten
the screws securely and evenly.
26. Connect the fast idle rod (18) between the fast idle lever (12) and fast idle cam lever (57). Secure the
rod in place with a cotterpin (not numbered in the drawing above) from the Fuelmiser kit.
27. Install the 1/8” NPT vacuum line spacer (
7/16” AF).
28. Place some rag in the inlet manifold to stop rubbish dropping in, then clean the manifold face. Clean
the Bakelite spacer.
29. Install new gaskets, the spacer and carburettor onto the inlet manifold flange nuts. Note that the
gaskets in Fuelmiser kit are incorrect for BXOV-1 carburettors, and must be replaced with alternative
ones. When seating the spacer, take care to pull it up squarely and gently, as flexing the spacer can
cause them to crack. Cracked spacers will cause a vacuum leak and poor running.
30. Refit the choke cable to the choke tube holder assembly (7). With the choke knob pushed in at the
dash, tighten the choke tube clamp screw (5) and choke wire clamp screw (3). Check the operation
of the choke from inside the vehicle, confirming that the choke plate fully opens and closes.
31. Reconnect the fuel and vacuum control lines.
32. Install the throttle control upper rod to the carburettor and fit a new split pin.
33. The air cleaner may remain off the vehicle until it is tuned as per the guidance below.
7.9 Replacement Parts
In addition to the Fuelmiser parts noted above, some parts are available from Stromberg Carburetor (see
image below, Stromberg Carburetor parts are above the Australian B-Model parts). The parts have been
verified by fitting against an Australian BXOV-1 carburettor:
Page 49 of 148
Part Bendix Australia
Part Number Stromberg Carburetor
Part Number Comments
Air horn attaching screw and lockwasher
(item 1 in the image above)
909521-K36 and 909522-K36
31095K
The threads are slightly sharper in the Stromberg Carburetor part, but a decent fit to the B-Model carburettor. The Stromberg Carburetor part is stainless.
Main metering jet plug (item 9 in the image
above)
P24678 Similar to the centre
plug piece in the 9522K kit.
The Stromberg Carburetor plug head is ½” diameter, whilst the B-Model is
7/16”. The Stromberg
Carburetor part engages by only one thread on the B-Model carburetor and seats on the outside of the body (rather than the milled internal seat) unless the plug head is ground back to ½” diameter.
A brass float 382537 9550K
Main metering jet (item 5 in the image above)
P19442-size 9533K-size.
Australian B-Model sizes were 0.049”-0.059”, with some need for even smaller sizes for the guys running twin and triple carburettors. Stromberg Carburetor have 0.033”-0.050” and can make bigger on demand.
Slow idle adjusting screw
and spring (spring is item 3
in the image above)
P15456, 2376174 or 903925-K1 for
the screw, P15831 for the
spring.
9589K
The Genuine Stromberg screw is a different thread (10-32x¾”) and hence not useable in B-Model carburettors. The spring is close, but a little longer (and stainless steel) and works nicely with the B-Model carburettors.
Idle needle valve and spring (items 7 and 4 in
the image above)
P15478 for the screw, P15481 for
the spring.
Should be similar to your 9541K. Pretty
much the same. Spring a tad longer.
Genuine Stromberg spring is slightly longer, but both screw and spring are a good fit for the B-Model carburettors.
Main metering jet plug gasket (item 10 in the image above)
383079 9563K Genuine Stromberg gaskets are paper, whilst Fuelmiser gaskets are malleable copper.
Pump check valve assembly (item 6 in the image above)
P18144
9573K Identical swap.
Throttle/choke valve attaching
screws (not pictured above)
P22573 or P20904
9586K Identical swap.
Power bypass jet assembly (item 2 in the image above)
382880-size 9594K-size
Note that the head of the B-model power valve is 0.407” diameter, whilst the head of the Stromberg Carburetor jet is 0.395” diameter. Despite the slightly smaller head, the Stromberg 97 power bypass jet seats well in the B-Model body.
Page 50 of 148
Australian B-Model sizes ranged from #54-#67 drill, with some need for even smaller sizes (higher drill number) for the guys running twin and triple carburettors. Stromberg Carburetor have #60-#71 and can make bigger on demand.
For the curious, the following GMH B-model parts were also checked against the Stromberg Carburetor
EE-model parts – whilst they look very similar, they are sadly not a direct fit. They may in some cases
however be made to fit (more or less) with some machining:
A choke shaft and plate (Bendix Australia part number 2376088
and P24046 respectively). These are similar to the Stromberg
Carburetor parts 9546K and 49K. However, the shaft is a
different style, the plate is a different shape (EE-Model is round)
and the B-model screws are not countersunk like the EE-model.
A stainless steel float pin. These are different to the EE-1 pin (no threaded end on
the Australian one).
A choke cable mounting bracket (Bendix Australia part number 385175 or 385174)
– very different to the Stromberg Carburetor part number 9552K-B.
A throttle plate (Bendix Australia part number 385050 or 2376062). Looks similar to
the Stromberg Carburetor part number 9585K. However the Australian one is
thinner, slightly bigger and steel – the EE-Model is brass.
A throttle shaft. The Stromberg Carburetor shaft is longer and thicker (7mm) than
the B-Model shaft (¼” or 6.35mm).
A main discharge jet (Bendix Australia part number 385178). Very different to the
Stromberg Carburetor part 9534K.
An idle jet (Bendix Australia part number P21778-size, and item 8 in the image above). Whilst similar
to the Genuine Stromberg part 9542K, the B-Model part is 17
/64” shorter. The longer EE-Model part
clashes with the B-Model main discharge jet, though is otherwise a fit. Genuine Stromberg offers the
#70 drill jet, with Australian B-Model jet sizes being #68 and #70 drill.
A float (Bendix Australia part number 382537). This is very similar to the Genuine
Stromberg part 9550K, though the B-Model float has a slightly different hinge and
has one corner removed. This part would require little modification to fit the B-
Model carburettor.
Page 51 of 148
Note that the needle and seat assembly (Bendix Australia part
numbers 385053 and 2376000) which is made by Fuelmiser is also
made by Genuine Stromberg. The Genuine Stromberg part (9564K) is
a two-ball type rather than the traditional needle and seat. The
Genuine Stromberg threads (7/16x24 on the carburettor end and ½x20
on the fuel line end) appear to match the B-Model, though I have not
trial fitted one.
Page 52 of 148
8 Tuning and Troubleshooting
Stromberg carburettors are renowned for being fiddled with. The image of
an early Holden with the bonnet up and someone bent over the engine
“tuning” the carburettor is almost iconic-Australian. Like any carburettor, it is
often easy to blame the carburettor for a host of other ignition faults. The
tuning below assumes that ignition, timing, valve train and engine condition
(e.g. compression) are in fair shape.
The basic Stromberg tune-up steps (say after overhauling the original
carburettor on the car) are:
Setting the fuel level,
Setting the idle speed and idle mixture, and
Checking the accelerator pump stroke.
Note that setting the idle mixture applies only to engine performance at idle conditions – not at normal
cruising, accelerating or under heavy load.
Where the vehicle is running incorrectly, or where new carburettors are fitted, there are an additional
three tuning parameters:
Tuning the accelerator pump stroke and duration (which determines throttle response),
Changing the main metering jets (which sets the mixture under cruising conditions), and
Changing the power bypass jets (which sets the mixture under heavy load).
8.1 Fuel Level
Fuel level is adjusted so that
the vehicle does not run out of
fuel (lean out) under cornering
or acceleration (too low) or
burp uncontrolled into the
engine (too high). The chart to
the right shows how each of
the fuel systems loses suction
as the fuel level drops in a
Stromberg BXOV-1
carburettor fuel bowl.
Fuel level is harder to set “by eye”, and some basic tools are needed:
A small steel rule to measure the fuel level.
A tool to bend the float lever. There is a GMH tool to do this (Tool No. 6A10), though a
screwdriver/pair of needle nose pliers works just as well.
To set the fuel level:
1. Place the vehicle on level ground. Warm the car up to normal operating condition.
2. Turn the engine off and remove the air cleaner.
0
0.5
1
1.5
2
2.5
emp
ty
mai
n m
eter
ing
and
id
le s
yste
ms
suct
ion
acce
lera
tor
syst
em
suct
ion
po
wer
sys
tem
su
ctio
n
low
er f
uel
leve
l
up
per
fu
el le
vel
ove
rflo
w f
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mai
n
dis
char
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Fue
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igh
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)
Page 53 of 148
3. Remove the five air horn attaching screws and lockwashers (10A) and the choke tube holder
attaching screw and lockwasher (10). Place the screws somewhere away from the engine…
dropping them down a carburettor throat can lead to catastrophic engine damage. Remove the air
horn assembly (16).
4. Raise the air horn gasket (17) to an out of the way position. Block off the power system vacuum
passage in the carburettor main body (37) with a piece of PVC tape (see
diagram to the right where the vacuum passage has been coloured red). If
this passage is not blocked off during fuel level setting, the manifold will
draw in air (bypasses the carburettor) and will not run well.
5. Start the engine and measure the level of fuel in the float bowl with a
steel rule. Measurements are taken from the liquid surface to the top
of the main body (37). The measurement should be 5/8”-
11/16”.
6. If the measurement is outside this range, stop the engine and bend
the float lever (either with GMH Tool No. 6A10, or a screwdriver/pair of
needle nose pliers). When adjusting the float tab, don't force the float
needle into its seat as it may damage the seal.
7. Remove the PVC tape from the vacuum passage, smooth down the
air horn gasket (17) and refit the air horn assembly (16). Reintall the
five air horn attaching screws and lockwashers (10A) and the longer
choke tube holder attaching screw and lockwasher (10), taking care
not to drop them down the carburettor throat. Tighten the screws firmly and evenly. Reinstall the air
filter.
Stromberg carburettors operate on approximately 2½-4½ psi of fuel inlet pressure (SUs are happy to run
on 1½-3½ psi and overflow around 5 psi, and 350 Holley carburettors run happily at 5-7psi). Too low a
fuel pressure and the fuel level drops in the bowl. Too high a level and the needle and seat is forced
open, flooding the engine. This is a particular risk when the original Holden mechanical fuel pump has
been replaced with an electric inline pump – see chart and table below. When using inline fuel pumps
(notably Holley), a pressure regulator is mandatory to prevent flooding.
Fuel Pump Maximum Pressure (psi) Free Flow (GPH)
Early Holden (grey/red glass bowl) 4½ 9
Later Holden (blue motor steel can) 3.9 9½
Carter GP4603HD 6 43
Carter GP4070 6 72
Carter GP4594, GP4389, GP4259 and GP4602RV 8 72
Carter GP4600HP 5 100
Holley Red 10 100
Carter GP4601HP 18 100
Holley Blue 18 110
Holley Black 18 145
Page 54 of 148
0
20
40
60
80
100
120
140
160
0 2 4 6 8 10 12 14 16 18
Flo
w (
GP
H)
Prressure (psi)
Holley red
Holley blue
Holley black
Stromberg inlet pressure
350 Holley inlet pressure
early Holden fuel demand
Pressure regulator required to drop Holley red pressure down to Stromberg 3½ -4½ psi inlet pressure range.
SU inlet pressure
Early Holden (grey and red) fuel pump: 3½ -4½ psi, 9 GPH freeflow
Page 55 of 148
8.2 Idle Speed and Idle Mixture
Engine idle speed is adjusted so that the vehicle does not stall when stationary (too low) or consume
excess fuel/jump when moving off (too high). Idle mixture is set to provide a good fuel/air combination
(neither too rich and “loading up” at idle, nor too lean and stumbling) when stationary. Whilst idle speed
and idle mixture can be set “by ear”, there are some tools that make it easier/more consistent:
A tachometer (either dash mounted or fed from the ignition leads) can help accurately set idle speed.
If a tachometer is unavailable, a timing light can be connected and the number of “flashes” in twelve
seconds counted. Multiply the number of flashes by ten to get the RPM. This is pretty hard to do
though – you are looking to count around four flashes per second.
A vacuum gauge (either dash mounted or a removable pressure gauge that screws into the inlet
manifold after disconnecting the vacuum wipers (FB and earlier Holdens) or power brake/windscreen
washers (NASCO accessories) from the manifold. The vacuum gauge gives a more accurate setting
to the idle mixture than the “back it off until it runs smooth” method.
To set the idle speed and mixture:
1. Warm the car up to normal operating condition. Check the choke is off. Leave the air cleaner in
place.
2. On automatics, the transmission should be in DRIVE (D) with the handbrake firmly engaged.
3. Fit the vacuum gauge to the inlet manifold and the tachometer (where available).
4. Adjust the slow idle adjusting screw (54) until the engine idles at 480-520 rpm (check with a
tachometer, timing light counting or “by ear”).
5. If you have a vacuum gauge, adjust the idle needle valve (59) until you get the highest vacuum
possible (this should be between 17”-21” Hg, or 60-70 kPa, or 8-10 psi). This can be difficult if the
vehicle has a large cam (high valve overlap) as the vacuum at idle will fluctuate. In this case, adjust
the idle needle valve (59) until the tachometer reads maximum rpm. If you don‟t have a vacuum
gauge or tachometer, turn the idle needle valve (59) slowly inwards until the engine starts to run
irregularly. Back the idle needle valve (59) outwards until the engine begins to “roll”, then inwards
again until the engine runs smooth.
6. Check the engine speed again, and repeat steps 3. and 4. above until a satisfactory idle is achieved.
7. Remove the tachometer and vacuum gauge and refit any vacuum lines that were disconnected.
If a rough idle persists after the mixture screws have been adjusted, check for vacuum leaks. These could
result from unplugged vacuum fittings, carburettor flange gaskets that were torn during installation,
cracked lines or loose bolt/screws. A quick way to check vacuum leaks is to spray WD40 in the suspected
area with the engine running – if the engine speed increases, there is a vacuum leak.
Whilst early Holdens, being manufactured prior to July 1972, are generally not required to comply with
emission standards. However, from that date onwards, all petrol passenger vehicles (and derivatives)
were required, when new, to comply with a performance standard (ADR) that set limits for exhaust
emissions of hydrocarbons (HC), oxides of nitrogen (NOx) and carbon monoxide (CO):
Page 56 of 148
ADR26 was introduced 1/1/1976, and captures the CO at idle test (limit of 4.5% maximum volume
CO).
ADR27, 27A, 27B and 27C applied to vehicles manufactured from July 1976 to January 1986.
Vehicles made in this period generally ran on leaded petrol and employed carburettors.
ADR37/00 covers the period from February 1986 to the present. Vehicles manufactured after
January 1986 generally run on unleaded petrol (catalytic convertors), with computerized engine
management systems, fuel injection.
A summary of the emissions requirements of each of the tests above can be found here:
http://www.infrastructure.gov.au/roads/environment/impact/emission.aspx. Most early Holdens will not
have to conform to the above. However, some engineers request the CO at idle test when vehicles have
been modified to the extent that they require an engineer‟s report. It is important to note that the idle test
is normally done at idle (480-520rpm). There is an alternative “high idle” test, which is conducted at
2500rpm. This test, although usually not applied to early Holdens, will bring the main metering circuit into
play (i.e. tuning for the CO at idle test is made via the idle needle valve (59), tuning for the “high idle test”,
if it was ever applied, is by changing the main metering jet). To tune the idle circuit to meet a CO at idle
test, an engine exhaust analyser is used – these are discussed more fully in Section 2.5.4 below. When
tuning for emissions, a CO at idle reading of 1-3% should be targeted.
Note that on vehicles with very lumpy cams, the large amount of valve overlap can mean that there is
very little vacuum at idle (6”Hg or less). At times, these vehicles may not respond well to setting the idle
mixture – the idle mixture screw seems to do little to help the idle. The low engine vacuum at idle means
that the throttle plates need to be opened more than usual to draw fuel from the idle system… in fact they
can be opened so much that the secondary idle discharge holes are uncovered, leading to excessively
rich idle (and no control of the idle mixture as the idle needle valve only controls the lower idle discharge
hole). To check for this, set the idle as best as possible, then remove the carburettor and check the
throttle plate position – if one or more of the upper idle discharge holes is exposed, then this may be the
cause of the loss of idle control. One method to fix this is to drill a 3/32”-
1/8” hole in the throttle plate on the
same side of the shaft as the idle discharge holes. The small hole will allow some air to pass, allowing the
throttle plates to be closed further and idle mixture control regained. This condition should not be
confused with an early opening power vacuum piston – see Section 8.8 below.
8.3 Accelerator Pump Stroke and Components
The accelerator pump stroke can be checked for standard settings as follows (though this should not be
necessary if it has been set on the bench during overhaul):
1. Start the vehicle and bring it to normal operating temperature and idle. This
sets the correct throttle closed position.
2. Turn off the engine and remove the air cleaner, air cleaner and air horn from
the carburettor.
3. Measure and record the distance from the top of the accelerator pump piston
stem to the top face of the carburettor body (with the gasket removed).
4. Open the throttle fully and again check and record the distance.
5. The difference between the two measurements (which is the accelerator
pump stroke) should be 13
/64”-15
/64”. If the difference is more or less than this
range, the accelerator pump stroke can be changed by bending the top horizontal portion of the
accelerator pump rod (24). Two bends are needed for each adjustment to keep the hole in the pump
rod parallel with the pump stem.
Page 57 of 148
The accelerator pump can also be tuned to give better throttle response. A larger or smaller engine will
want more or less fuel added when the throttle is opened. Bear in mind that the accelerator pump is
responsible for the initial acceleration only – most of the acceleration up to final speed is done by either
the main metering or power circuits. The following table gives some guidance on observations seen when
initially cracking the throttle (and assumes the accelerator pump, ignition and timing is in good working
order):
Observation Cause Tuning
Engine is lazy for a few seconds then begins accelerating (sometimes fluttery). Opening the throttle more slowly makes the issue go away.
Too much or too long of a pump squirt.
Change to heavier pump stem spring or pack washers under
spring.
Puff of black smoke from exhaust that quickly clears. Opening the throttle more slowly makes the issue go away.
Engine stumbles then begins accelerating.
Too little or too short of a pump squirt.
Change to lighter pump stem spring or cut portions of the
spring coils away. Engine backfires during accelerating.
The duration of the pump squirt is determined by three issues:
the stiffness of the pump stem spring (25). Early Holdens up to EJ (including EK
and EJ manuals) had spring number 7405169. This spring is copper coloured and
heavier (to the point that it can hold automatic vehicles throttle part closed as per
the Service Bulletin to the right). EK and EJ automatics had spring part number
7423236. This spring is cadmium plated and lighter. EH, HD and HR (excluding S
engine) had 7424555. HR S engine had VS10488. It is possible to pack washers
under the spring to increase the spring stiffness, or to carefully remove spring coils
(say ½ a coil at a time) to reduce spring stiffness.
the size of the pump bypass jet (27). All early Holdens used a No. 56 drill (0.0465”) accelerator
pump bypass jet. Pump bypass jets are stamped with the jet size in drill number (e.g. a jet
stamped 56 has a 0.0465” diameter hole drilled in it). In theory the pump bypass jet can be
drilled out to a larger size (giving a faster pump squirt), though the drilling process would need
to be very careful, as the area immediately behind the jet hole (marked by the red arrow in the
diagram to the right) contains a small valve stem and spring which could readily be drilled
through. A blind drill bit would be preferable…my guess is that finding a set of blind jet drills
would be like finding rockinghorse poo.
the size of the pump discharge nozzle. Grey motors used a No. 70 drill (0.0280”) discharge nozzle,
EH/HD/HR red motors used a No. 72 drill (0.0250”). Note that the accelerator pump system has no air
bleed – fuel is sent to the carburettor throat without being made into an emulsion. This means that the
pump discharge nozzle has the task of atomizing the fuel. It does this by pressure drop over the
nozzle – just like putting your finger over the end of the garden hose. Putting a bigger pump discharge
nozzle into the carburettor (or drilling the existing one oversize) will cause more fuel to flow as the
pump discharge nozzle is far smaller than the pump bypass jet (i.e. the discharge nozzle is a bigger
Page 58 of 148
restriction). However, making the pump discharge nozzle bigger means that the fuel is not as well
atomized – you may get more in, but it doesn‟t burn as well. The pump bypass jet (27) is a better
tuning point (and easier to reverse if you choose too big a bypass pump jet).
The volume of the pump squirt is determined by how far the pump piston and stem assembly (26) moves
down the pump well bore.
The accelerator pump on Stromberg BXOV-1 carburettors may also be adjusted by putting the pump link
into one of the three different holes in the pump lever. Note that the FB Workshop Manual provides the
following guidance:
“The capacity of the accelerator pump is correctly calibrated at the pump stroke of 9/32” and under no
circumstances should the pump stroke be adjusted by shifting the pump link from the centre hole of the
pump lever. The inner and outer holes in the pump lever provide too great a variance in the pump stroke
and must result in reduced performance and economy”.
Whilst some enthusiasts find that there is little feelable difference between the three holes when running
single carburettors, changing hole settings may help more with multiple carburettors. I have measured the
following info from a BXOV-1 carburettor using a dial run-out gauge - the table below gives the fuel
delivery for the three pump link holes:
Pump Link Setting Delivery per stroke
Outer (furthest from throttle shaft pivot) 1.2mL
Centre (middle) 0.87mL
Inner (closest to throttle shaft pivot) 0.3mL
From the chart above, the inner hole delivers a lot less fuel, and finishes doing so at a lower throttle shaft
rotation. The centre and outer holes deliver more fuel, and do so over a wider throttle shaft rotation. Note
that at all settings, the accelerator pump finishes squirting (20-35o) well before the throttle shaft finishes
turning (throttle shaft typically finishes at 65o):
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
0 10 20 30 40
Pu
mp
Ou
tpu
t (c
c)
Throttle Shaft Rotation (o)
Outer
Centre hole
Inner
Page 59 of 148
8.4 Idle Vent Valve Lift
For BXUV-2 and BXV-2 carburettors, once the engine idle speed and accelerator pump stroke have been
adjusted, the idle vent valve lift can be set. The following process is used:
1. Start the vehicle and bring it to normal operating temperature and idle. This sets the correct throttle
closed position. Ensure that the choke is fully off (open).
2. Stop the engine and measure the vertical lift of the idle vent valve stem as the throttle lever is moved
from the fully open to the fully closed position.
3. Hold the idle vent valve washer and screw the idle vent valve stem up or down until a lift of 0.040-
0.060” is achieved. Tighten the locknut.
4. Open and close the throttle several times then recheck the lift dimension. Repeat steps 2-3 until the
correct lift is achieved.
8.5 Wide-Open Throttle (WOT) Adjustment
The linkage between the accelerator pedal and throttle plate is a complex affair on FB/EK Holdens –
there are eleven bearing points that can jam with old grease and dirt, a number of brackets and rods that
can get bent over the last half decade, and plenty of opportunity for the message from your right boot to
get mixed up before it gets to the carburettor. It is time well spent following through the linkage from the
accelerator pedal through to the carburettor, giving each bearing point a clean up with a rag dipped in
kerosene and a light dab of grease. Don‟t expect to find any fancy roller bearings – all the bearings here
are simple metal rods swinging through holes in brackets.
If the throttle linkage is not adjusted correctly, the carburettor will not open fully at full throttle, and top-end
performance is reduced. To adjust the throttle linkage on manual vehicles:
1. Disconnect the pull back spring from the throttle control adjusting bracket.
2. Have an assistant hold the accelerator pedal just above the floor mat/carpet (1/8-
3/16”).
3. Loosen the throttle control adjusting bracket attaching bolt (coloured red in the diagram below), then
pull the carburettor throttle lever by hand until the throttle plates are wide open (you can see this by
looking down the carburettor throat). The throttle control adjusting bracket will move in an arc, up or
down as required to obtain the correct adjustment.
4. Tighten the throttle control adjusting bracket attaching bolt securely.
5. Reconnect the pull-back spring.
6. Recheck the engine idle speed, as it is possible that the throttle plates have been pulled slightly
more open.
Throttle shaft
rotation
Idle 0o
WOT 65o
Inner setting 20o
Outer setting35o
Centre setting 33o
Page 60 of 148
Page 61 of 148
To adjust the throttle linkage on automatic vehicles:
1. Adjust the throttle control adjusting bracket (labeled “slotted bracket” in the diagram below) such that
the end of the upper cross shaft lever is in the centre of the bracket slot.
2. Check that the underside of the pivot end of the upper cross shaft lever clears the welded body joint
by approximately3/8” when the lever is in the fully returned position. If necessary, loosen the throttle
control adjusting bracket lock nut and move the lever up or down to obtain this clearance.
3. Disconnect the throttle valve connecting rod at the linkage end. This rod is not shown in the diagram
below, and connects a lever on the left hand side of the transmission case to the throttle linkage.
4. Depress the accelerator pedal slowly until the underside of the pedal just contacts the kick-down
button on the floor. Check that the carburettor throttle valve is fully open without compressing the
throttle over-travel spring. If necessary, loosen the locknut on the lower cross shaft rod and adjust
the length of the rod as required. Tighten the locknut.
5. Reconnect the throttle valve connecting rod at the linkage end.
6. Check adjustment by road testing to ensure the transmission will kick-down into second gear only
when the accelerator pedal is pressed through the kick-down detent position at a road speed of 40
mph. Minor adjustment of the lower cross shaft rod may be required, though major adjustment will
require repeating steps 1-5 above and can indicate that the throttle valve lever on the transmission
case is incorrectly set or the levers or rods are bent/worn.
7. After adjusting the throttle linkage, reset the idle speed with the engine in Drive.
Note that the linkages on EJ, EH, HD and HR Holdens are different from the EK linkage shown
above. Excellent diagrams and instructions can be found in The Scientific Publications Workshop
Manual Series No. 67 Holden covering series 1948/‟53 FJ, FE, FC, FB, EK, EJ, EH, HD, HR for
these vehicles.
Page 62 of 148
8.6 Main Metering Jets
The purpose of the main metering jet is to provide the correct air/fuel mixture under intermediatry throttle
positions (“cruise”). Whilst the factory jet sizings are a good starting point (see table below), changes in
fuel quality in the last fifty years (for example the increase in octane and the addition of ethanol) can
make engines run considerably leaner than when they left the GMH factory.
A lean fuel mixture (primary metering jets too small, too little fuel for the amount of air in the cylinder) may
be seen by one of more of the following:
a miss or stumble whilst cruising at constant throttle opening,
a flat spot when you put your foot down part way (this may happen after split second when the initial
squirt from the accelerator pump is used up),
the engine runs hot… and if it is very lean, then the valves are burnt,
the sparkplugs are white or very pale… and if it is very lean, the electrodes start to show signs of
being eroded/burnt away (rapidly followed by engine valves and cylinder crowns…),
power is reduced, and
pulling the choke out slightly reduces the problem.
A rich fuel mixture (primary metering jets too large, too much fuel for the amount of air in the cylinder)
may be seen by one of more of the following:
the engine surges at constant throttle, though there is no flat spot when the throttle's floored.
if the mixture is way too rich it will cough and splutter until the throttle's held wide open under load
(where the power bypass jet takes over). There can be a smell of unburnt fuel from the exhaust
when it is held at mid-throttle.
the spark plugs can be fouled and black, and
the vehicle runs sluggishly.
A number of main metering jets are available for Stromberg carburettors, both factory and aftermarket.
Main metering jets are stamped with the jet size in thousandths of inches (e.g. a jet stamped 56 has a
0.056” diameter hole drilled in it). Of note:
A range of main metering jets (typically 0.041”-0.068”) are held in stock by the Carburetor Service
Company. I have extended the table below to show this range.
I have listed below the main metering jets made by Stromberg Carburetor Ltd for Stromberg 97
carburettors. The Stromberg 97 (model EE-1) jets commonly available for the hotrodder market do fit
the B series carburettors (for example 1942-1953 Fords and Mercurys fitted with Stromberg 97s
used the exact same part number main metering jet as early Holdens, though in 0.043” and 0.044”).
Note that Stromberg Carburetor Ltd are also able to supply customs sizes other than those listed
below, though you must order through one of their dealers. Rocket Industries is the Australian dealer
for Stromberg Carburetor Ltd, and stock the 0.041”, 0.043”, 0.045” and 0.047” main metering jets at
the time of writing this document, and are able to ship in the other sizes in a weeks delivery time.
Note that the Stromberg Carburetor Ltd jets are at the small (lean) end of the scale, and are more
likely to be useful to those running twin or triple carburettors than those running singles.
Whilst American Auto Parts lists twentysix main metering jets on their website ranging from 0.040”-
0.067”, they do not physically stock any of the jets at the time of writing this document.
Where the correct size main metering jet is not available, it is possible to solder up a jet and redrill it
to the correct size. This requires a very precise set of drill bits – to be honest, for most enthusiasts
the effort involved to hunt down the right drill bit is equal to that of finding the right
jet from the sources above. Jet drills in metric sizes are common (and very cheap
at the time of writing this document via eBay). Fractional imperial drills in small
sizes are a lot harder to find, but are available as a set from Rocket Industries
(Part number BG130050, Barry Grant jet drills sizes #61 to #80 (0.135" to .039"))
and as individual drills from Lee Brothers Engineering in Parramatta. When soldering jets, lead
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solder is acceptable to use as the typical lead solder melting point is around 180ºC – petrol boils
between about 20ºC and 210ºC… if the carburettor is hot enough to melt the solder, it‟s already
boiling out most of the fuel. Care must be taken though as lead solder is very soft, and easily
damaged. Silver solder (melting point above 450ºC) is somewhat harder.
The table below provides some guidance for initial tuning (the bigger the main metering jet size, the more
rich the engine runs):
Jet Size GMH Part Number
Stromberg Carburetor
Ltd Part Number
Standard for
← R
ICH
ER
0.033 - 9533K-33 -
0.034 - 9533K-34 -
0.035 - 9533K-35 -
0.036 - 9533K-36 -
0.037 - 9533K-37 -
0.038 - 9533K-38 -
0.039 - 9533K-39 -
0.040 - 9533K-40 -
0.041 - 9533K-41 -
0.042 - 9533K-42 -
0.043 - 9533K-43 -
0.044 - 9533K-44 -
0.045 - 9533K-45 -
0.046 - 9533K-46 -
0.047 - 9533K-47 -
0.048 - 9533K-48 -
0.049 VS10535 9533K-49 HR S high altitude 8000-12000 ft (186ci)
NOTE
1
0.050 7403431 9533K-50 48, 50, FJ (132.5ci)
0.051
7405264
VS10534
-
48, 50, FJ, FE, FC (132.5ci) FB, EK, EJ (138ci)
EH high altitude 8000-12000 ft, HD economy (149ci)
HR high altitude 8000-12000 ft and economy (161ci)
HR S high altitude 4000-8000 ft (186ci)NOTE 1
0.052 - - -
0.053
7420385
VS10533
- EH high altitude 4000-8000 ft (149ci) HR high altitude 4000-8000 ft (161ci)
HR S (186ci)NOTE 1
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0.054 - - -
0.055 7420388 -
EH, HD (149ci) HR (161ci)
EH high altitude 8000-12000 ft, HD economy and X2 (179ci)
HR economy and X2 (186)
0.056 - - -
0.057 7424569 - EH high altitude 4000-8000 ft (179ci)
0.058 VS10185 - EH, HD excluding X2 (179ci)
HR excluding S and X2 (186ci)
0.059 7420412 - EH, HD excluding X2 (179ci)
0.060 - - -
0.061 - - -
0.062 - - -
0.063 - - -
0.064 - - -
0.065 - - -
0.066 - - -
0.067 - - -
0.068 - - -
NOTE1: HR 186S engines (WW Stromberg) have a different main metering jet to the B-Model Stromberg carburettors used in earlier Holdens (and Stromberg 97s). The 186S main metering jet is
15/32” long overall, and can be further identified by a line
stamped under the jet size on the shank and a 1/32”x
1/64” groove cut into the
shank (as per the image to the right). The earlier B-Model (and Stromberg 97s) Stromberg carburettors had main metering jets with an overall length of 33
/64” with no grooves cut in the shank (as per the image to the left). The metering orifice in the two types of jet are different, and produce different flow characteristics (e.g. the 0.051” main metering jet used in the EK Holden
will flow differently to the 0.051” main metering jet used in the HR 186S engine high altitude 4000-8000 ft operation). This means that although you can use WW main metering jets in a B-Model carburettor, the range of the WW jets is different to the B-model ones – this can make things tricky when “stepping through the jet sizes” during tuning. The simplest way can be to make sure that all the jets you are “stepping through” are either all WW or all B-model.
Changing the main metering jet is as simple as:
stopping and letting the engine cool (as some fuel will be drained onto the inlet manifold),
removing the main metering jet plug (44) with a stubby flat-head screwdriver (or the fancy tool that comes with some jet keys),
removing the main metering jet (42) with a Stromberg jet key (or GMH tool 6A12) and screwing the new jet in,
replacing the metering jet plug gasket (43) and reinstalling the main metering jet plug (44).
There is also an aftermarket adjustable main metering jet (sometimes referred to as an adjustable main jet or adjustable jet, American Auto Parts SBP-039) available for Stromberg carburettors. The adjustable main metering jet is essentially a needle valve that screws into (and replaces) the original main metering jet plug. The adjustable main metering jet is used in conjunction with a special main metering jet that is much larger than the engine will ever need. The special jet (pictured in the lower left of the adjacent photograph) has a tapered seat to suit the needle – standard main jets have a square shouldered jet. In this case the special jet does not provide the restriction to do the metering – the needle valve does.
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Adjustable main jets have their good points (you only need to buy one adjustable jet rather than several fixed jets to get the right one), together with their shortcomings (the temptation to fiddle with them or go hunting for better fuel economy can lead to over-lean conditions and burnt valves, the o-ring seal can leak over time). As an initial tuning point, the following may be used:
bring the engine up to operating temperature,
hold the engine speed at around 3000-3500rpm (mid throttle).
Slacken the lock nut on the adjustable jet then screw the adjuster in slowly until the engine speed starts to alter and run a little bit rough. Wind back the adjuster until the engine speed pick up and the engine no longer runs rough.
Tighten the lock nut.
There are a number of ways to select the correct main metering jet (or correctly adjust an adjustable main metering jet):
reading the spark-plugs,
measuring exhaust gas carbon monoxide, and
running the car on a dyno/strip (more applicable to the power bypass jet – see section 2.5.5 below).
Each of these methods should be undertaken in conjunction with road testing, looking for stumbles, flat spots, drivability and fuel consumption.
Reading the colour of the spark plug electrodes (and to a lesser extent the colour of the exhaust pipe) provides a cheap and easy guide to correct main metering jet choice. This technique involves driving the vehicle for a run (up to operating temperature and a moderate distance at “cruise” conditions – not all at idle or full throttle!). After stopping then cooling down the engine, each plug is removed in turn and the colour of its electrode compared. Today the use of unleaded fuels and high-energy ignition systems has made this method much harder because very little color is seen on the spark plug; however the pictures below give some guidance:
A more full description of spark plug readings can be found at
http://www.classiccarhub.co.uk/articles/spark_plugs.html.
Overly lean (main metering jet is too small). Whitish or pale deposits. May also be seen by erosion of the spark plug electrode or detonation damage of the insulator.
Correct jetting: electrode deposits are slight and not heavy enough to cause any detrimental effect. Colour is brown to greyish tan colour, and minimal amount of electrode erosion.
Overly rich (main metering
jet is too large): Soft, black,
sooty deposit.
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A much more accurate way to tune the main metering jets is to measure the carbon monoxide (CO) in the
vehicle exhaust. CO is one of the gases in the engine exhaust (along with nitrogen (N2), carbon dioxide
(CO2), water (H2O), hydrocarbons (unburnt fuel, often written as HC), and various nitrogen oxides (NOX)
and sulphur oxides (SOX). The amount of CO in a vehicle exhaust is an indicator of the air/fuel mixture
being supplied to the engine, and thus is an excellent way of tuning jet sizes on carburettors.
Manufacturers typically specify a CO level somewhere within the range 0.5% to 3.5% by volume. At CO
levels higher than this there is a loss in economy, and at very rich settings, typically 8% to 10% CO, the
onset of poor running occurs, characterized by the particular engine sound that is known as “hunting”. It
should be noted that an engine, even in good overall condition, will show a fluctuation in idle CO over a
period of time, of typically 0.5%. To measure CO, a sample probe is placed into the exhaust pipe and an
exhaust gas analyser unit “reads” the CO in the exhaust. The other readings that some exhaust analyzers
provide include HC (the best mixture gives you the lowest HC), CO2 (the best mixture gives you the
highest CO2 reading) and O2. Whilst workshop units can cost in excess of $4000, a simple and cost
effective exhaust analyser (the “Gastester Digital”) is available from Gunsen for around $250 (see
http://www.gunson.co.uk/item.aspx?item=1835). This would not be a bad investment if you are planning
to tune a few early Holdens over the years. Using this analyser, some starting points for tuning would be
to tune to 0.75-1.25% CO (1–3% CO for a lumpy-cammed engine) at cruise conditions.
8.7 Power Bypass Jets
The purpose of the power bypass jet is to provide the correct air/fuel mixture under heavy throttle
positions (towing, moving up hills or racing). Whilst the factory jet sizings are a good starting point (see
table below), changes in fuel quality in the last fifty years again makes for some tuning change.
A number of power bypass jets are available for Stromberg carburettors, both factory and aftermarket.
Power bypass jets are stamped with the jet size in drill number (e.g. a jet stamped 56 has a Nº.56 drill or
0.0465” diameter hole drilled in it).
Of note:
I have listed below the power bypass jets made by Stromberg Carburetor Ltd for Stromberg 97
carburettors. The Stromberg 97 (model EE-1) power bypass jets commonly available for the
hotrodder market do fit the B-Model carburettors. The only difference is that the head of the B-model
jet is 0.407” diameter, whilst the head of the Stromberg 97 (EE-1) jet is 0.395” diameter
(see image to the right). Despite the slightly smaller head, the Stromberg 97 power
bypass jet seats well in the B-Model body. Note that Stromberg Carburetor Ltd are also
able to supply customs sizes other than those listed below, though you must order through one of
their dealers. Rocket Industries is the Australian dealer for Stromberg Carburetor Ltd, and stock the
Nº.69 power bypass jet at the time of writing this document. Rocket Industies are able to ship in the
other sizes in a weeks delivery time. Note that the Stromberg Carburetor Ltd jets are at the small
(lean) end of the scale, and are more likely to be useful to those running twin or triple carburettors, or
for single carburettored grey motors rather than for red motors.
In theory the power bypass jet can be drilled out to a larger size (giving a richer mixture under
load), though the drilling process would need to be very careful, as the area immediately
behind the jet hole (marked by the red arrow in the diagram to the right) contains a small
valve stem and spring which could readily be drilled through. A blind drill bit would again be
preferable…my guess is that finding a set of blind jet drills would be like finding rockinghorse
poo.
The table below provides some guidance for initial tuning (the bigger the main metering jet size, the more
leaner the engine runs – this is the opposite of main metering jets!):
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Jet Size Diameter GMH Part Number Stromberg Carburetor
Ltd Part Number
Standard for
← L
EA
NE
R
54 0.0550” 7424565 - EH (179ci)
55 0.0520” 7420747 -
EH, HD excluding X2, HR (179ci)
HR excluding X2 and S (186ci)
56 0.0465” 7420490 -
EH, HD, HR (149ci)
HR (161ci) HD normal and
economy excluding X2
(179ci) HR X2 and
economy (186ci)
57 0.0430” 7424564 - EH (149ci)
58 0.0420” -
59 0.0410” -
60 0.0400” - 9594K60 -
61 0.0390” - 9594K61 -
62 0.0380” - 9594K62 -
63 0.0370” - 9594K63 48, 53
(132.5ci)
64 0.0360” - 9594K64
65 0.0350” 7406899 9594K65
FB, EK, EJ (138ci)
HD economy (149ci)
HR economy (161ci)
66 0.0330” - 9594K66 -
67 0.0320” - 9594K67 FJ, FE, FC (132.5ci)
68 0.0310” - 9594K68 -
69 0.0292” - 9594K69 -
70 0.0280” - 9594K70 -
71 0.0260” - 9594K71 -
Note that whilst it appears that the HR Holden 186S (WW-Model) power bypass jet is interchangeable
with the early B-Model (and hence Stromberg 97) power bypass jets, the HR Holden valve has two Nº.56
drill (0.0465”) holes (i.e. much larger capacity) than the B-model single-hole power bypass valves. For
those seeking dual-hole WW power bypass jets, it is likely that Stromberg Carburetor Ltd (via Rocket
Industries) could supply a double-drilled jet.
Changing the power bypass jet is a little more complicated than changing a main metering jet. The process is as follows: 1. Remove the air cleaner wingnut, air cleaner lid and filter element. Slacken off the slot-head bolt
under the filter base then remove the base.
2. Slacken off the choke tube clamp screw (5) and choke wire clamp screw (3). Pull the choke cable out
from choke tube holder assembly (7). Leave the choke cable hanging from the firewall.
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3. Remove the cotter pin (not numbered in the drawing above) from the lower end of the fast idle rod
(18) then remove the rod.
4. Undo the five flat-head air horn attaching screws and lockwashers (10A) and the choke tube holder
attaching screw and lockwasher (10). Note that 10A and 10 are very similar – 10 is slightly longer to
allow for the thickness of the choke tube holder.
5. Lift off the air horn assembly (16).
6. Using a large flat bladed screwdriver, unscrew and remove the power bypass jet assembly (21) and
the associated gasket (22) from the main body (37). Screw the new power bypass jet assembly and
gasket in place.
7. Reverse the above steps to reassemble the air horn.
One method to tune the power bypass jet is to use timed acceleration runs (e.g. ¼-mile times), or top speed/power (e.g. dyno-tuning). This involves trial and error jetting changes to obtain the best results, and needs some moderate track or dynamometer time to get decent repeatable results. An easier way is to again tune using an exhaust analyser (particularly if you have the Gunson exhaust analyser described in Section 2.5.4 above). Some starting points for tuning would be to tune to 6.6% CO under load conditions. Whilst this could be reduced to 4% for engines with very good combustion chamber design, early Holden cylinder heads rarely meet this criteria.
8.8 Vacuum Power Piston
Whilst the Stromberg B-Model power bypass jet is readily able to be tuned for flow (bigger or smaller power bypass jet orifices), it is harder to tune for when (or at what vacuum) it opens. The standard vacuum power piston opens at 6”Hg. For most early Holden applications, there is approximately 17-21”Hg of vacuum at idle, meaning that the power bypass jet is well and truly shut at idle (as it should be). However, vehicles with a large overlap (lumpy) cam can idle at 6” Hg or lower. At this vacuum, the power bypass jet can open and will start to feed the mixture, leading to the vehicle “loading up” at idle. For these engines, a power valve is required that opens at lower vacuum. Whilst it is possible to disassembly the vacuum power piston (say to fit a lighter spring), the main stem has a very heavy swage that holds the assembly together. The photo to the right shows the stem swage (circled in red), which is visible after tapping out the covering cap (seen to the lower right of the image). The swage would be very difficult to remake when reassembling - it is likely that the stem would be inadvertently bent, rendering the piston useless. A pin is also possible (by cross-drilling the main stem), though not very practicable as the swage/pin would need to fit into the (fairly tight) piston recess. The simplest option is to modify the existing spring in-situ. To lower the vacuum setting (e.g. from the standard 6”Hg to 4”Hg), the spring in the power piston is shortened. To shorten the spring: 1. Set the idle mixture as described in 8.2 above. Check that the idle upper discharge holes have not
been uncovered at idle (i.e. that the secondary idle system is not the source of the excess fuel at idle) in line with the guidance in 8.2 above.
2. Ensure that the vehicle main metering jets are reasonably sized and not the cause of the over-richness at cruise. This may be done by placing a few small washers on top of the power bypass jet to prevent the vacuum power piston from depressing the pin, then checking the exhaust gas quality under cruise conditions (see 8.6 above). Remove the washers and refit the air horn assembly. Check that the exhaust gas quality now runs very rich again under idle conditions.
Having ruled out the idle and main metering systems as the source of excess fuel, shorten the spring: 3. Remove the air cleaner wingnut, air cleaner lid and filter element. Slacken off the slot-head bolt
under the filter base then remove the base.
4. Slacken off the choke tube clamp screw (5) and choke wire clamp screw (3). Pull the choke cable out
from choke tube holder assembly (7). Leave the choke cable hanging from the firewall.
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5. Remove the cotter pin (not numbered in the drawing above) from the lower end of the fast idle rod
(18) then remove the rod.
6. Undo the five flat-head air horn attaching screws and lockwashers (10A) and the choke tube holder
attaching screw and lockwasher (10). Note that 10A and 10 are very similar – 10 is slightly longer to
allow for the thickness of the choke tube holder.
7. Lift off the air horn assembly (16).
8. Remove the vacuum power piston using a pair of circlip pliers and carefully trim a single coil from the
spring with a pair of sidecutters.
9. Refit the vacuum power piston and refit the air horn assembly. Check that the exhaust gas quality,
and repeat the trimming steps until the vehicle returns to a reasonable idle quality.
10. Repeat steps 3-9 for cruise conditions if the vacuum is sufficiently low to allow the power bypass jet to open at cruise.
Note that it is also possible to increase the vacuum setting at which the vacuum power piston will open. This may be done to match the springs in multiple carburettor setups such that all carburetors open at the same vacuum. Increasing the vacuum setting is achieved by fitting brass washers under the spring, making the spring stiffer. To do this, 1. Remove the air cleaner wingnut, air cleaner lid and filter element. Slacken off the slot-head bolt
under the filter base then remove the base.
2. Slacken off the choke tube clamp screw (5) and choke wire clamp screw (3). Pull the choke cable out
from choke tube holder assembly (7). Leave the choke cable hanging from the firewall.
3. Remove the cotter pin (not numbered in the drawing above) from the lower end of the fast idle rod
(18) then remove the rod.
4. Undo the five flat-head air horn attaching screws and lockwashers (10A) and the choke tube holder
attaching screw and lockwasher (10). Note that 10A and 10 are very similar – 10 is slightly longer to
allow for the thickness of the choke tube holder.
5. Lift off the air horn assembly (16).
6. Remove the vacuum power piston. Compress the spring with your fingers and temporarily hold it in place with a cable tie. This prevents the spring being damaged whilst manipulating the washers below.
7. Take a 1/8” brass washer (I have used Zenith EBG4003‟s here from
Bunnings), and cut the washer on one side. Bend the washer open like a spring washer.
8. Fit the bent brass washer to the vacuum power
piston shaft and bend it back into shape, taking care that the washer cut closes.
9. Refit the vacuum power piston and refit the air horn assembly. Check that the exhaust gas quality,
and repeat the addition of washers until the desired opening point is achieved. The following table gives some guidance as to how the vacuum setting will change with various modifications to the vacuum power piston spring on BXOV-1 carburettors (the changes will be slightly different for the BXOV/BXUV carburettors installed from mid-EH Holden onwards which had a longer vacuum power piston):
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Spring Change Vacuum Setting (“Hg)
6 coils removed 1.5
5 coils removed 2.5
4 coils removed 3.5
3 coils removed 5
2 coils removed 5.5
1 coil removed 6
Standard 6 3/32” thickness of washers added 7
3/16” thickness of washers added 12
For vehicles that run wide-open throttle most of the time (like HQ Holden circuit racers), the Stromberg power valve is often removed (blanked off) and the main jet sizes increased to suit. Whilst this is suitable for full throttle performance, it will lead to a very rich “cruise” condition and is not recommended for street use.
8.9 Troubleshooting
It is common knowledge that “carburettor” is French for “don‟t F%@# with
it”. Many Australian children have learnt to swear from listening to the
carefully phrased epithets gently wafting from the open bonnet of an early
Holden. The guidance below may assist in hunting down the cause of early
Holden Stromberg issues (and perhaps prevent your children from
developing their vocabulary). Of note, many ignition and timing issues are
found to be the real cause of what is perceived to be a “bad carby” – the
following table assumes all electrical and timing issues have been resolved.
Fault Part to Check Condition to
Look For Remedy
Carburettor flooding
Float needle and seating
Worn or dirt on seat.
Replace or clean the float needle and seating.
Float Punctured or
damaged. Replace the float.
Fuel level Too high. Reset to correct float level (bench) or fuel level (on-vehicle).
Fuel pump Pressure too
high.
Service the fuel pump, or check that replacement electrical pump pressures are compatible (4½ psi maximum).
Difficulty cold starting
Main metering jet and idle tube
Obstructed.
Clear the main metering jet and idle tube by:
Remove the air filter assembly.
Start the vehicle and allow it to warm up to operating temperature.
Place your hand over the top of the carburettor air horn, and give the vehicle a number of full-throttle revs (don‟t panic… it won‟t suck you hand in!).
Remove your hand and refit the air cleaner.
, otherwise disassemble to clear.
Float bowl Dripping/weeping, leading to empty
float bowl on
Tighten the main metering jet plug and pump check valve plug. Replace the copper washers if leaks persist.
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startup.
Float needle and seating
Sticking closed. Replace the float needle and seating.
Fuel pump Fuel pressure and volume insufficient.
Service the fuel pump.
Fuel line (fuel tank to pump)
Leakage. Tighten all unions and replace them if leaks persist.
Choke valve
Not closing fully due to:
Bent choke shaft. Replace the choke shaft.
Choke valve rubbing on air
horn.
Slacken the securing screws slightly and centralize the valve plate.
Choke shaft bearing areas
coked (carboned) up.
Clean away the coke.
Air horn distorted. Replace the air horn.
Choke cable (wire) not
connected or snapped.
Tighten or replace the choke cable (wire).
Automatic choke valve not closing
correctly (HR 186S engines
only)
Check for free travel and good condition of all parts. Check and reset the thermostat and all other automatic choke settings.
Carburetor flange and inlet
manifold gaskets Air leaks.
Find the leaking gasket by spraying WD40 around the gaskets with the engine running (a cold engine will decrease the risk of the WD40 igniting off hot surfaces). Engine speed increases when WD40 is sprayed around leaking gaskets. Tighten nuts and replace gaskets if the leaks persist.
Difficulty hot starting
Float chamber baffle plate (HR 186S engines
only)
Baffle plate missing.
Install a new baffle plate.
Idle tube Obstructed.
Clear the idle tube by:
Remove the air filter assembly.
Start the vehicle and allow it to warm up to operating temperature.
Place your hand over the top of the carburettor air horn, and give the vehicle a number of full-throttle revs (don‟t panic… it won‟t suck you hand in!).
Remove your hand and refit the air cleaner.
, otherwise disassemble to clear.
Incorrect type Replace with the correct type idle tube.
Fuel level Too high.
Ensure the float is not punctured or damaged. Reset to the correct float level (bench) or fuel level (on-vehicle). If the level builds up, check the float needle and seating and the fuel
Page 72 of 148
pump pressure (4½ psi maximum).
Idle vent valve (BXUV-2, BXV-2
and WW carburettors
only)
Incorrect opening Set the idle vent valve to the correct lift.
Choke valve
Not opening fully due to:
Bent choke shaft. Replace the choke shaft.
Choke valve rubbing on air
horn.
Slacken the securing screws slightly and centralize the valve plate.
Choke shaft bearing areas
coked (carboned) up.
Clean away the coke.
Air horn distorted. Replace the air horn.
Choke lever return spring
broken. Replace the choke return spring.
Choke cable (wire) not
connected or snapped.
Tighten or replace the choke cable (wire).
Choke cable too short.
Adjust the choke cable to allow 1/8” slack in
the cable when choke is fully open.
Automatic choke valve not opening
correctly (HR 186S engines
only)
Check for free travel and good condition of all parts. Check and reset the thermostat and all other automatic choke settings. Ensure the hot air pipe is not loose, blocked or broken. Replace the thermostat cover gasket and tighten the cover screws securely. Check that the throttle body hot air vacuum hole is clear.
Poor idling
Idle tube
Obstructed.
Clear the idle tube by:
Remove the air filter assembly.
Start the vehicle and allow it to warm up to operating temperature.
Place your hand over the top of the carburettor air horn, and give the vehicle a number of full-throttle revs (don‟t panic… it won‟t suck you hand in!).
Remove your hand and refit the air cleaner.
, otherwise disassemble the idle tube to clear.
Incorrect type Replace with the correct type idle tube.
Not seating at shoulder (B-
Model) or collar near head of tube
(WW-model).
Replace the idle tube (all Models). Tighten the idle tube securely (B-Model carburettors)
Idle air bleed Carboned up or
obstructed. Clear the obstruction, taking care not to enlarge the idle bleed hole.
Idle discharge holes
Obstructed. Clear the idle discharge holes by:
Remove the air filter assembly.
Page 73 of 148
Start the vehicle and allow it to warm up to operating temperature.
Place your hand over the top of the carburettor air horn, and give the vehicle a number of full-throttle revs (don‟t panic… it won‟t suck you hand in!).
Remove your hand and refit the air cleaner.
Otherwise manually clear the obstruction, taking care not to enlarge the idle discharge holes.
Idle restrictor rod (BXUV-2 and
BXV-2 carburettors)
Idle restrictor rod missing.
Install an idle restrictor rod.
Throttle shaft bearing areas
Worn and leaking air.
Find leaking bearing areas by spraying WD40 around the outside of the air horn with the engine running (a cold engine will decrease the risk of the WD40 igniting off hot surfaces). Engine speed increases when WD40 is sprayed around leaking bearing areas. Rebush the worn bearing areas.
Throttle shaft Worn. Replace the throttle shaft.
Carburetor flange and inlet
manifold gaskets Air leaks.
Find the leaking gasket by spraying WD40 around the gaskets with the engine running (cold engine will decrease the risk of the WD40 flashing off). Engine speed increases when WD40 is sprayed around leaking gaskets. Tighten the flange nuts and replace the gaskets if leaks persist.
Throttle body bore
Carboned up. Clean the throttle body bore.
Throttle valve
Carboned up. Clean the throttle valve.
Throttle valve rubbing on
throttle body.
Slacken the securing screws slightly and centralize the valve plate.
Idle needle valve
Bent or damaged taper.
Replace the idle needle valve.
Incorrectly set. Adjust to the correct setting.
Fuel level Too high or too
low.
Ensure the float is not punctured or damaged. Reset to the correct float level (bench) or fuel level (on-vehicle). If the level builds up check the float needle and seating and the fuel pump pressure (maximum 4½ psi).
Air horn gasket (HR 186S
engine only)
Not sealing idle passages and
vacuum channels.
Replace the air horn gasket and tighten the securing screws evenly.
Throttle body to main body
gasket
Not sealing idle passage.
Replace the throttle body to main body gasket.
Throttle lever Loose on shaft. Tighten the throttle lever shaft nut.
Idle vent valve (BXUV-2, BXV-2
and WW Incorrect opening Set the idle vent valve to the correct lift.
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carburettors only)
Choke kick diaphragm and
connecting hose (HR 186S
engines only)
Leaking. Replace the diaphragm or hose.
Dashpot (HR 186S engines
only)
Plunger clearance
incorrect, dashpot plunger
misaligned.
Set the plunger clearance to specifications correct plunger alignment.
Poor acceleration and flat spots
Accelerator pump piston
Piston leather worn, creased,
too hard, too soft or loose on shaft. No or little fuel is
seen in carburettor throat when throttle is
pressed.
Replace the accelerator pump piston.
Accelerator pump piston
spring
Insufficient or excessive tension.
Replace the accelerator pump piston spring.
Accelerator pump linkage and throttle
linkage
Worn (sloppy), allowing lost
motion.
Replace the worn parts, or fit a Fuelmiser Lost Motion Spring.
Accelerator pump stroke
Incorrect stroke. Reset the pump stroke to the correct measure (bench or in-vehicle). Ensure the pump link is on the correct (middle) hole of pump lever.
Accelerator pump intake check valve
Obstructed by dirt or not seating. No
or little fuel is seen in
carburettor throat when throttle is
pressed.
Clean or replace the accelerator pump intake check valve.
Accelerator pump bypass
valve
Not seating, corroded or
incorrect size. No or little fuel is
seen in carburettor throat when throttle is
pressed.
Replace the accelerator pump bypass valve.
Accelerator pump nozzle
(HR 186S engines only)
Nozzle obstructed. No or little fuel is seen
in carburettor throat when
throttle is pressed.
Clean or replace the accelerator pump nozzle.
Leaking nozzle gasket. No or little
Replace the accelerator pump nozzle gasket.
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fuel is seen in carburettor throat when throttle is
pressed.
Obstructed pump channels. No or little fuel is seen
in carburettor throat when
throttle is pressed.
Clean the accelerator pump channels.
Accelerator pump jet (B-
Models)
Obstructed. No or little fuel is seen
in carburettor throat when
throttle is pressed.
Clear the accelerator jet and pump channel with air pressure.
Idle tube Partially
obstructed.
Clear the idle tube by:
Remove the air filter assembly.
Start the vehicle and allow it to warm up to operating temperature.
Place your hand over the top of the carburettor air horn, and give the vehicle a number of full-throttle revs (don‟t panic… it won‟t suck you hand in!).
Remove your hand and refit the air cleaner.
Otherwise disassemble and clear the idle tube with air pressure or replace.
Idle discharge holes
Obstructed.
Clear the idle discharge holes by:
Remove the air filter assembly.
Start the vehicle and allow it to warm up to operating temperature.
Place your hand over the top of the carburettor air horn, and give the vehicle a number of full-throttle revs (don‟t panic… it won‟t suck you hand in!).
Remove your hand and refit the air cleaner.
Otherwise manually clear the obstruction, taking care not to enlarge the idle discharge holes.
Idle mixture setting
Too lean. Adjust the idle mixture screw to give a richer setting (screw them out).
Main metering jet
Wrong size or obstructed.
Replace the main metering jet.
Vacuum power piston
Worn, damaged or stuck in the up
position. Replace the vacuum power piston.
Power bypass jet
Obstructed or corroded.
Clear the obstruction or replace the power bypass jet.
Fuel level Too low. Reset to correct the float level (bench) or fuel level (on-vehicle).
Automatic choke valve (HR 186S
Not opening correctly.
Check for free travel and good condition of all parts. Check and reset the thermostat and all
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engines only) other automatic choke settings. Ensure the hot air pipe is not loose, blocked or broken. Replace the thermostat cover gasket and tighten the cover screws securely. Check that the throttle body hot air vacuum hole is clear.
Multiple carburettors
Not synchronized. Synchronise the carburettors.
Oversized venturi.
Fit a smaller venturi carburettor pair or install venturi sleeves.
Lack of maximum
speed or power
Air cleaner Choked
(blocked). Clean the air filter element, or replace the element if it is the dry element type.
Throttle valve Not opening fully. Adjust the throttle linkage.
Fuel supply Insufficient. Clear any obstructions in the fuel lines and check the fuel pump for correct delivery volume and pressure.
Main metering jet
Obstructed, wrong size or
type, damaged.
Clear the main metering jet by:
Remove the air filter assembly.
Start the vehicle and allow it to warm up to operating temperature.
Place your hand over the top of the carburettor air horn, and give the vehicle a number of full-throttle revs (don‟t panic… it won‟t suck you hand in!).
Remove your hand and refit the air cleaner.
Otherwise manually clear the obstruction, taking care not to enlarge the main metering jet hole or replace the jet.
Main discharge jet
Damaged tip, crushed or
enlarged side holes.
Replace the main discharge jet.
High speed bleeder
Enlarged high speed bleeder
hole. Replace the high speed bleeder.
Vacuum power piston
Stuck in the up position.
Clean the vacuum power piston and bore. Replace the vacuum power piston if damaged. Do not lubricate the vacuum power piston or bore.
Power bypass jet
Incorrect size, corroded or obstructed.
Replace the power bypass jet. Clear the power bypass jet passage with air pressure.
Fuel level Too low. Reset to the correct float level (bench) or fuel level (on-vehicle).
Choke valve
Not opening due to:
Bent choke shaft. Replace the choke shaft.
Choke valve rubbing on air
horn.
Slacken the securing screws slightly and centralize the valve plate.
Choke shaft bearing areas
coked (carboned) up.
Clean away the coke.
Air horn distorted. Replace the air horn.
Choke lever Replace the choke return spring.
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return spring broken.
Choke cable too short.
Adjust the choke cable to allow 1/8” slack in
the cable when the choke is fully open.
Automatic choke valve (HR 186S engines only)
Not opening correctly.
Check for free travel and good condition of all parts. Check and reset the thermostat and all other automatic choke settings. Ensure the hot air pipe is not loose, blocked or broken. Replace the thermostat cover gasket and tighten the cover screws securely. Check that the throttle body hot air vacuum hole is clear.
Excessive fuel consumption
Carburettor, fuel lines and fuel
tank Leakage.
Replace the gaskets and washers and tighten unions.
Idle tube Loose in body. Tighten the idle tube.
Main metering jet.
Wrong size, wrong type or
damaged. Replace the main metering jet.
Main discharge jet.
Damaged tip, bad top shoulder seat,
bad seat with main metering jet,
side holes crushed or obstructed.
Replace the main discharge jet.
High speed bleeder.
Obstructed. Clear the high speed bleeder with air pressure or replace.
Fuel level. Too high.
Ensure the float is not punctured or damaged. Reset to the correct float level (bench) or fuel level (on-vehicle). If the level builds up check the float needle and seating and fuel pump pressure (maximum 4½ psi).
Vacuum power piston.
Worn, damaged spring, stuck in
the down position,
blockage in vacuum channel, PVC tape left on vacuum passage
following fuel level check.
Replace the vacuum power piston. Clear the channel.
Power bypass jet.
Wrong size, valve not seating,
washer defective or missing.
Replace the power bypass jet and washer.
Accelerator pump link
In furthest pump lever hole (pump stroke too long)
Place the pump link in the centre hole of the pump lever.
Idle vent valve (BXUV-2, BXV-2
and WW carburettors
only)
Incorrect opening Set the idle vent valve to the correct lift.
Choke valve Not opening due
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to:
Bent choke shaft. Replace the choke shaft.
Choke valve rubbing on air
horn.
Slacken the securing screws slightly and centralize the valve plate.
Choke shaft bearing areas
coked (carboned) up.
Clean away the coke.
Air horn distorted. Replace the air horn.
Choke lever return spring
broken. Replace the choke return spring.
Choke cable too short.
Adjust the choke cable to allow 1/8” slack in
the cable when the choke is fully open.
Automatic choke valve (HR 186S engines only)
Not opening correctly.
Check for free travel and good condition of all parts. Check and reset the thermostat and all other automatic choke settings. Ensure the hot air pipe is not loose, blocked or broken. Replace the thermostat cover gasket and tighten the cover screws securely. Check that the throttle body hot air vacuum hole is clear.
Multiple carburettors
Not synchronized. Synchronise the carburettors.
Oversized
venturi. Fit a smaller venturi carburettor pair or install venturi sleeves.
Page 79 of 148
9 Bigger Stromberg Swap
There are some engine combinations where the original single-barrel Stromberg carburettor becomes
restrictive. It is common practice for enthusiasts to go hunting for a larger carburettor in the search for
more power. Carburettors are often rated in terms of the amount of fuel/air mixture they can flow at a
given manifold vacuum. The flow rate is expressed in cubic feet per minute, or CFM. Care needs to be
taken though in that a given carburettor may have several different venturi sizes, and hence several
different flowrates (for example the BXUV-2 carburettor was offered in both 1/32” and
3/32” venturi sizes for
early Holdens). The manifold vacuum used to measure flow rate also varies. Some early published
ratings for 1-barrel (e.g. B –Model Stromberg) and 2-barrel (e.g. WW-Model Stromberg) carburetors were
measured at 3” Hg. 4-barrel carburettors (for example Holley 4150 carburettors) were rated at 1½”Hg.
The table below has been compiled from information on multiple websites. I have converted the
Quadrajet, Weber, and SU values to 3”Hg (they were published at 1.5”Hg). I have taken a single
published figure for Stromberg BXOV-2 carburetors (210CFM) and converted to the smaller BXOV-1 and
BXUV-2 carburettors by calculation based on the venturi and throttle bore diameters. The upshot of the
above is that the table below is very approximate, but should give some indication of the relative flowrate
achievable with different carburettors.
Carburettor Barrels Venturi diameter Flowrate (CFM @3”Hg)
Weber 38-DGAS 2 36mm/36mm 600
Rochester Quadrajet 4 2¼ “/1.35” 530
Mikuni 44 PHH 2 37mm/30mm choke 422
Holley 7448 (“350 Holley”) 2 13/16”/1
3/16” 350
SU HIF6 1 Variable 339
Weber 28/36-DCD 2 26mm/27mm 317
SU HS6 1 Variable 297
Stromberg BOV-2 (the “big brother swap”)
1 19/32” 287
WW Stromberg 2 128
/32”/ 128
/32” 280
Weber 32/34-DMTL 2 26mm/27mm 274
Weber 32/36-DGV 2 26mm/27mm 270
Weber 32/36-DGV 2 23mm/27mm 235
Stromberg BXV-2 1 15/32” 210
Stromberg BXUV-2 1 13/32” 201
SU HS4 1 Variable 201
SU H4 1 Variable 188
Holley EGC 2 11/16”/ 1
1/16” 185
Stromberg 48 2 11/32”/1
1/32” 175
Stromberg BXOV-1 1 13/32” 162
Holley 94/8ba 2 15
/16”/ 15
/16” 162
Stromberg LZ 2 1”/1” 160
SU H2 1 Variable 156
Holley 94/59 2 15
/16”/ 15
/16” 155
Stromberg 97 2 31
/32”/ 31
/32” 150
Holley 92 2 7/8”/
7/8” 142
Stromberg 81 2 13
/16”/ 13
/16” 135
I will focus here on fitting larger Stromberg carburettors. The BXOV-1 Stromberg fitted to Holden grey
motors is very similar in design and operation to those fitted to later red motors. It is tempting to fit a later
(and bigger) BXV-2, BXUV-2, or larger Stromberg carburettor - venturi sizes start at 11/32" (grey motors),
and move through 13/32" (149ci and 161ci red motors) and 1
5/32” (173ci, 179ci and 186ci motors) to 1
7/32”
(202 motors). Note that these are not hard and fast rules though as there are some small venturis used
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on larger motors (for example HR and HK 161ci taxi engines used 11/32” venturis). Fitting a larger
Stromberg carburettor can lead to better open-road performance on a standard grey motor, and is often
done where racing vehicles need to comply with class requirements. For example:
the current CAMS Group Na rules require carburettors to be of the make and model originally
available pre-1958, though bore size is free.
CAMS Group Nb (the old Appendix J and Group N class) rules allow later models of carburettors
which were available in the period pre-1965 to be used, even with different throat sizes, provided
that the outward appearance is the same.
Australian Speedway Lightning Sprints may use two single barrel Stromberg carburettors of 15/32”
venturi which must be externally stock standard though may be converted to methanol internally.
The following provides some guidance for swapping to a larger Stromberg carburettor:
Care needs to be taken in that the bolt spacing for the BXOV-1 carburettor (23/8”) is
different from that of the BXUV-2 and BXV-2 carburettors (211
/16”). The standard
grey motor inlet manifold can be removed and the studs ground off. The manifold
is then drilled and tapped to suit the larger bolt spacing. An alternative method is to
make a spacer plate and use offset studs.
The BXOV-1 throttle bore diameter (15/16”) is identical to that of the BXUV-2
carburettor, but smaller than the BXV-2 carburettor (17/16”). The centre of the
standard grey motor manifold will need to be ground out to meet the increased
throttle body bore if using the BXV-2 or larger carburettors. Care needs to be taken
that the gaskets used match up to the new bore size – no use having a large bore
carburettor if it‟s trying to breathe past a tiny gasket hole.
The stock inlet manifold can be made to breathe easier by splitting the
manifold lengthwise across the flanges and grind out the centre of the
manifold. The manifold is then furnace brazed back together. This was an
old production class racing trick used when Holden inlet manifolds were
class mandated.
Moving to a larger Stromberg carburettor means that the carburettor will
need to be re-tuned in its new home – the stock idle settings and jets may
not be applicable to the smaller motor, and may need to be downsized to get a reasonable tune.
There is a “big brother” swap that has been used in some dedicated race
vehicles. This utilizes the Ford Stromberg with 19/32” venturis from 250ci 1V
Ford motors (later 250ci 2V crossflow motors used twin-venturi Strombergs
and Webber carburettors). Some caution is needed in fitting a carburettor this
big to a grey motor – the Ford carburettor was originally designed for vehicles
with almost double the cylinder capacity of the Holden grey. Serious
headwork, valve train, exhaust (and the accompanying bottom end to stop it
all grenading) is required to run the “big brother” single Stromberg carburettor.
Whilst I‟m no Ford expert, Falcon XA/XB (and maybe XY) and Cortina TC/TD
250ci 1V engines (lower right image) were BOV-2 type. These have a
“normal” flange (not a cross-flange like the BXOV-1), and put the linkage in an
awkward position for the standard grey motor manifold (not to mention
running the float north-south, where acceleration surge will play with fuel
level). The Falcon XC, XD and TD/TE/TF (upper right image) were a form of
BX carburettor with a cross-flange similar to Holdens. These would appear to
orient the linkage and float correctly for the original grey motor manifold.
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10 Multiple Carburettors (Twins and Triples)
Whilst twin and triple carburettors were never available from the factory for early Holden grey motors (the
first twins being available on HD Holden 179ci X2 red motors long after the death of the grey motor), they
remain a popular period-correct performance addition to many vehicles. Some enthusiasts believe that
multiple carburettors offer an advantage where the fuel has less far to travel down the manifold
(compared to a single, larger or two-barrel carburettor). This infers less fuel drop out and better supply.
Spreading the fuel supply points (from one point to two or three along the manifold) can also assist in
getting more even fuel distribution to the cylinders – the single Stromberg carburettor has a tendency to
“overfeed” the centre cylinders at the expense of cylinders one and six. Alternatively, other enthusiasts
believe that the multiple power valves associated with twin and triple Stromberg carburettors can supply
too much fuel and do not open simultaneously, leading to erratic transition from cruise to power.
The Holden grey motor is renowned for being “asthmatic”, with twin carburettors one way of making them
breathe easier. Whilst it helps to be able to breathe in more, it is of little use if you can‟t breathe it out. The
factory Holden grey motor exhaust manifold is just as restrictive as the inlet side, and is best modified
(headers or extractors) to get the full benefit of multiple carburettors.
10.1 Carburettor Model and Manifold Choice
Assuming that you have a manifold and are trying to decide on what
carburettors to fit to it, the starting point will be to make two measurements –
the bolt spacing, and the throttle bore diameter (see picture to the right).
The bolt spacing, is measured between the studs (or bolt hole) centres on the
manifold. The bolt spacing for the BXOV-1 carburettor (23/8”) is different from that of
the BXUV-2 and BXV-2 carburettors (211
/16”). Although you can sometimes drill and
retap the manifolds to change the bolt spacing, it is a lot easier to choose the right
carburettors to suit the manifold.
The throttle bore diameter is measured across the “holes” in the manifold. If the
carburettor and manifold throttle bore diameters do not match up, the resultant “step”
in the fuel path can lead to either fuel drop-out or reduced flow. The throttle bore
diameter for the BXOV-1 and BXUV-2 carburettors (15/16”) is different to that of the
BXV-2 carburettor (17/16”). It is possible to mill out a 1
5/16” manifold to 1
7/16”, or to
swap a BXOV-1/BXUV-2 throttle body onto a BXV-2 carburettor, it is again easier to
choose the right carburettors to suit the manifold.
Having made the two measurements, it is now time to think about what venturi size to pursue. Most
enthusiasts find that for Holden grey motors, the Stromberg carburettor of choice in twin and triple
applications is the BXOV-1 or HD/HR/HK taxi BXUV-2 (both have 11/32” diameter venturis and the same
throttle bore diameter, just different bolt spacing). Whilst it is possible to run the larger BXUV-2 (13/32”
venturi) or BXV-2 (15/32” venturi) carburettors in twin or triple configuration, there is no need to do so on
the grey motor. The larger venturi diameter can lead to decreased mid-range acceleration – see notes
below on venturi sleeves.
The table below summarises the different bolt spacings, throttle bore diameters and venturi sizes
available, together with the Code number stampings to look for on eBay and at swapmeets:
Page 82 of 148
Vehicle Holden 48-EJ
Holden HD 149ci and HR and HK 161ci economy (taxi) engines.
Holden EH 149ci engines, HD, HR, HK, HT, HG and LC 149ci and 161ci engines, some HD 179ci engines, HR and HK 186ci economy (taxi) engines and HR 186ci X2 engines.
Holden EH and
some HD 179ci
engines, HD, HR
(excluding taxi
and X2), HK
(excluding taxi),
HT and HG 186ci
engines
Stamping 23-105D, 23-3000 and 23-
3001
23-3011 and 23-3022
23-3002, 23-3005, 23-3007, 23-3009, 23-
3010 23-3012, 23-
3013, 23-3015, 23-3016, 23-
3019, 23-3021, 23-3023 and
23-3024
23-3003, 23-3008, 23-3006, 23-3014
and 23-3020
Bolt Spacing 23/8” 2
11/16”
Model BXOV-1 BXUV-2 BXV-2
Venturi Diameter 11/32” 1
3/32” 1
5/32”
Throttle bore diameter 15/16” 1
7/16”
Note that the venturi diameter is normally cast into the side of the main
body adjacent to the float needle valve seat (1/32” in the case of the
BXOV-1 carburettor pictured in the image to the right).
10.2 Linkages
Whilst there are a limited number of twin and triple carburettor throttle linkage kits available “off the shelf”,
in the end most linkages are made from an assortment of parts sourced from your local speed shop.
Speco Thomas manufacture a fair range of these components – see below.
Part Speco Thomas Part No. Image
W-clips 221139 (pack of 1) 221140 (pack of 2)
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Ball joint assembly 221093.A
Where „A‟ is the dimension shown in the image (2”-12” in 1” increments)
Ball joint rod 221094 (available 2”-12”)
Ball joint 221097 (left-hand thread)
221098 (right-hand thread)
Ball joint ball 221108 ¼” 221106
5/16”
Uniball 221099
Throttle rod 221150 (21” x 5/16”)
Throttle rod stops 221174 (pack of two, suits 5/16” rod)
Carburettor arm 221102 (suits 5/16” rod)
Accelerator cable clamp
221145 (3/16” swivel)
Accelerator cable stop
221146 (3/16” swivel)
Accelerator cable stop (holder)
221144 (¼” thread)
Stud and nut kits 221159 (¼”x
5/16”
221156 (2”x5/16”)
221158 (3¼”x5/16”)
Throttle springs 221163 (SU spring, swivel ends)
221166 (long)
There are a number of types of linkage setup, some of which are dependent on the manifold type. I will try
to describe them using the Speco Thomas part names above in italic text for clarity.
Page 84 of 148
The “W-clip” linkage – the aim of W-clip linkages
is to use a throttle rod (common shaft) to join
(marry) the original throttle shafts of the
carburettors together. Both carburettors thus
operate as one unit. One end of each W-clip slides
over the original carburettor throttle shaft, whilst the
other end clamps to the new throttle rod. Also
clamped to the throttle rod is a carburettor arm.
The carburettor arm needs to be moved to
operate the carburettors – this is most often
achieved by fitting an accelerator cable stop or
accelerator cable clamp to the end of the
carburettor arm and converting the vehicle to a
cable accelerator setup (see Section 10.2 below).
The carburettor arm has several sets of holes to
allow different accelerator pedal travels to be
accommodated. The pictures above show the W-
clip linkage in both twin and triple carburettor
format. Whilst fairly low cost, the W-clip linkage
must be removed in order to get to the main jets,
as the shaft is in the way. The shafts also develop
a considerable amount of slop over time due to poor clamping of the W-clips and carburettor arms.
In W-clip linkage setups, the choke plates on each of the carburettors should be linked (joined) together.
It is poor practice to connect just one choke and leave the other one (or two) swinging in the breeze as
they may swing closed. The chokes can be linked with a fixed length of steel or wire - you can even use a
hacksaw blade and use the two choke cable screws. For vehicles which do not operate in a cold climate,
the second (and third) choke plate may not be necessary, and the actuating lever can be wired into the
open position.
Note that the W-clips mount to the throttle shaft in two ways. On the rear carburettor, the pump lever nut
is removed, and the W-clip is slid over the throttle shaft before replacing the nut. On the front carburettor,
the W-clip similarly mounts under the throttle lever nut. However, on BXOV-1 carburettors, the throttle
shaft does not have a nut on the throttle lever end – the throttle shaft is peined over instead. On the later
BXUV-2 and BXV-2 carburettors the throttle shaft does have a nut on the throttle lever side. This means
that W-clips cannot be used on the BXOV-1 carburettors unless the throttle shafts are replaced. There
are also two types of W-clips being produced. The black W-clips seen beside the cadmium plated
carburettor arm and throttle rods in the two images above have D-shaped holes at one end, which allow
them to be slipped directly over the D-shaped profile of the Stromberg throttle shafts. The W-clips being
Page 85 of 148
produced by Speco Thomas have round holes at both ends, and must
be used with adaptors to fit to the Stromberg throttle shafts (see image
to the right). The adaptors are threaded at one end to fit the throttle
shafts, and round bar at the other end to fit the W-clips.
Manifold-mounted linkage - some manifolds can run a manifold-
mounted linkage. These linkages typically have a throttle rod
mounted to the inlet manifold – some by bolt-on brackets (see
image to the right, an off-the-shelf linkage stocked by American
Autos as part number LINKIT) and some by using loop bosses
cast into the manifold (see drawing below). Some also attach the
throttle rod to the top of the carburettor air horns (see pictures of a
Lanspeed manifold with red air cleaners in Section 10.8 below).
Like the W-clip linkages, manifold-mounted linkages aim to
operate the two (or three) carburettors equally. Two (or three) separate carburettor arms (one for each
carburettor) are clamped to the throttle rod and connected to each carburettor throttle lever by ball joint
assemblies. As the carburettors are not connected (married) together like the W-clip linkage, this type of
linkage is often referred to as a divorced setup. The throttle rod is again fitted with a single carburettor
arm which needs to be moved to operate the carburettors. Because the throttle rod is much longer than in
W-clip linkages, there is more ability to move the carburettor arm closer to the firewall, allowing many
manifold-mounted linkages to be connected by a ball joint assembly to the original throttle control
adjusting bracket. In some cases, the original lever on the upper cross shaft assembly is extended by a
piece of flat bar. The better type set-ups use hexagonal throttle rods to avoid the clamps slipping. The
beauty of divorced-type linkages is that each carburettor may be adjusted as it has its own ball joint
assembly. The image below shows a typical manifold-mounted linkage which uses loop bosses and the
original throttle control adjusting bracket – note that I have shifted the carburettors to the left of the image
and simplified the manifold outline for clarity.
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Similarly to W-clip linkage setups, the choke plates on each of the carburettors should be linked (joined)
together when using manifold-mounted linkages.
Progressive linkage – progressive linkages are normally seen with triple (though sometimes twin)
carburettors. Whilst this form of linkage also typically mounts to the manifold, the way in which the
carburettors operate is different. The aim of the progressive linkage is to allow the vehicle to operate on a
single carburettor at light loads (economy), with more carburettors being activated as the throttle opens
more (power). Setups are often made such that the middle
carburettor (in triple configurations) is the light-load
carburettor, with the two outer carburettors coming on line
under load. Off-the-shelf progressive linkages are widely
available, for example from Speedway Motors
(http://static.speedwaymotors.com/pdf/560-6271.pdf).
However, most of these linkages assume the carburettors
have aligned throttle shafts – Stromberg B-Model
manifolds normally have the throttle shafts between the
carburettors. Stromberg B-model progressive linkages
usually use either a sliding eye or sliding rod type
progressive ball joint connection (see image to the right). The carburettor used for light loads (labelled the
economy carburettor) is normally driven by the original throttle control upper rod (which sometimes must
be extended). This is indicated by the red arrow in the image above. The economy carburettor then drives
the other two carburettors (labelled power carburettors above) via the progressive ball joint connection.
The economy carburettor throttle arm can turn a significant amount before the sliding eye bottoms out (or
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the sliding rod hits its stop) and the power carburettors start to be activated. A typical layout is shown
below:
Quite some thought is required to scratch-build a progressive linkage – for example, the economy
carburettor has little shaft movement left when the power carburettors open – this small movement must
be amplified into full throttle movement for the power carburettors by carefully selecting carburettor arm
length and angle. In progressive linkage setups, it is common to connect the economy carburettor to the
standard choke cable, and either wire the power carburettor choke levers fully open or remove the choke
plates. This is because at the low throttle startup conditions, only the economy carburettor is working –
the throttle plates on the power carburettors are fully shut. A triple Stromberg progressive linkage (see
pictures of a Speco manifold with rectangular chromed air cleaners) is also shown in Section 10.8 below.
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10.3 Accelerator Linkage to Cable Modification
With some manifolds and linkages, it is possible to use the original throttle linkage (the swinging bar type)
with a little bending. However, most manifolds and linkages will not allow their use no matter how much
they are bent. It is often easier to convert the throttle linkage to a cable type, eliminating the complex
linkage. A number of pedal/cable assemblies can be mounted into FB/EK Holdens, notably HZ Holden
and Commodore.
A neat (and simple) solution is to retain the
original FB/EK pedal, and modify it to suit the
cable from a Mitsubishi L300 Express van.
These vehicles were sold from 1980-1986,
and look similar to the photographs to the
right. Note that the later models however do
not have the required clevis at the cable end. The Mitsubishi L300 accelerator cable is quite long, and can
be shortened with a simple pair of sidecutters to the correct length once installed.
To undertake the conversion:
1. Remove all the throttle linkage except the pedal.
Remove the clip connecting the lower cross shaft operating rod to the accelerator pedal (under the
car),
Unbolt the lower cross shaft assembly (four phillips-head bolts located under the car).
Remove the clip connecting the upper cross shaft operating rod to the upper cross shaft assembly.
All the linkage from under the car should now fall out
Unbolt the upper cross shaft support (two phillips-head bolts per bracket, one bracket on drivers
and passengers side of firewall.
Disconnect the throttle control upper rod from the carburettor. All the linkage from in the engine bay
should now fall out.
Don‟t discard all the parts yet – the upper cross shaft support from the passenger‟s side makes a good
bracket for supporting the cable later.
2. Attach the Mitsubishi L300 accelerator cable clevis to the original Holden accelerator pedal, using the
hole that the lower cross shaft operating rod mounted to (under the car). The cable can be attached
with a pin and split pin, or by using a small bolt and nylock nut (do not overtighten the nut as it will bind
the clevis).
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3. The cable will now run into the cabin using the Mitsubishi L300 cable guide. You will need to drill a
hole in the floorpan for the cable to pass through, and another two for the cable guide mounting bolts.
Mount the cable guide using nuts, bolts and spring washers, with some sealant under the cable guide
to prevent water ingress to the cabin. The photographs above show the mounting of the clevis and
cable guide on a number of vehicles.
4. Run the cable inside the cabin, up the firewall (under the carpet/floor mat) and pass it out through the
grommet where the original choke cable passes through. The picture to the right
shows the cable routing with the carpet/floor mat removed.
5. The cable then passes across the engine bay to the carburettor throttle linkage. The
cable must be mounted, similar to the way that the choke tube holder assembly
mounts the original choke cable (the photograph below to the right shows a holder
assembly fitted to a Holley carburettor, and the photograph to the left to a twin
Stromberg setup).
6. The cable setup often feels much lighter than the original throttle linkage, and an extra (or heavier)
return spring can assist in returning the pedal feel. The photo below to the right shows a return spring
mounted off a bracket on the original battery tray.
7. The cable assembly should be checked and adjusted so that the carburettor both achieves wide open
throttle, and returns to idle. It‟s a good idea not to cut the cable to final length until this has been done.
In some cases, it may be necessary to extend the accelerator pedal lever (by welding on a piece of flat
bar) in order to get enough pedal travel to attain full throttle.
10.4 Fuel and Vacuum Lines
When plumbing twin and triple Stromberg carburettors, the terms “fuel rail” and “fuel block” are bandied about, making the fuel lines sounds a lot more complex than they really are. A fuel rail is really a piece of pipe feeding fuel to both carburettors, and a fuel block is really a glorified tee-piece. Fuel lines should be run from the fuel pump to an area close to the carburettors in steel line, supported to stop it rubbing due to vibration. Brake repair shops are not a bad place to get some fuel lines bent and fittings flared on, though try to run the lines in the largest size you are able to. Closer to the carburettors you can continue to run in steel line (neater), or you can run in rubber fuel hose. It is a good idea to double-flare fuel lines where they meet rubber hoses, as the rounded flare “lump” can stop the hose clamps (jubilee clips) blowing off – care needs to be taken though that the ends of the steel lines are smooth and will not cut the rubber hose. I have also seen quite a few fuel systems run in copper pipe, however many engineers frown on the use of copper pipe in fuel systems (and absolutely forbid it in brake systems) because vibration can lead to the copper lines work-hardening and cracking – cracked fuel lines under pressure at
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freeway speeds are no laughing matter. The photos below give some good guides as to how the fuel lines can be run. The original B-Model carburettors used on early Holdens had a vacuum connection (a steel line) that connected from the carburettor, snaked it‟s way around the rocker cover and connected to the distributor vacuum advance. This connection needs to be replicated in multiple carburettor setups. When thinking about this vacuum line, it is important to realize that there are two types of vacuum commonly tapped off a fuel system: • Manifold vacuum (sometimes referred to as full vacuum), which is used for brake boosters and
vacuum wipers. It is tapped off from the inlet manifold, or on the carburettor throttle body at a position below the throttle plates. You get more manifold vacuum when you take your foot off the throttle (this is why pre-EK vacuum wipers work so well when you lift your foot, but run poorly when you have your boot into it driving uphill in the pouring rain!).
• Timed-spark vacuum (sometimes referred to as distributor vacuum) is taken from above the throttle plates. Timed spark vacuum is exactly the same as manifold vacuum – except that it is shut off under zero throttle (i.e. under idle conditions, there is huge manifold vacuum, but zero distributor vacuum). The strategy behind distributor vacuum (generally used in later-model carburettors) is to remove vacuum advance at idle, causing the vehicle to run hotter and combust exhaust emissions (often with the help of air injection systems at the exhaust manifold).
Early Holdens were designed to run timed spark vacuum (the vacuum port connection is at the throttle body above the throttle plate – see diagram to the right). There is no harm in running distributor vacuum with multiple carburettors (by tapping into one carburettor and blocking the other one off - tapping into both carburettors and using a tee-piece is absolutely unnecessary). However, for cars with large cams (high valve overlap and poor vacuum), tapping into manifold vacuum (and blocking off the distributor vacuum ports on both the carburettors) can give better vacuum signal at idle, more advance and hence better idling. This can also reduce engine temperature at idle.
10.5 Venturi Sleeves
By adding a second (or third) carburettor, the “hole” to allow air into the engine has effectively doubled (tripled) in size. Whilst this is good for air flow, it can do some interesting things inside the carburettor, where pressure is critical. By doubling (or tripling) the “hole”, the pressure in the venturi has reduced. Of note:
The idle system, which operates below the venturi, still sees the same pressure and acts similarly to a single carburettor (see tuning notes below).
The main metering system takes vacuum signal from inside the booster venturi, which in turn takes signal from the main venturi. With lower pressure means that less fuel is taken per carburettor (though there are now two carburettors feeding). The slower air speed also means that the fuel delivered is not atomized as well as a single carburettor.
The accelerator system sees no difference in having two (or three) carburettors, as it is purely mechanical and not vacuum driven (see tuning notes below).
The power system sees no difference in having two (or three) carburettors, as it takes it‟s signal from the manifold pressure (just like the idle system).
The choke system sees no difference in having two (or three) carburettors as it operates above the venturi.
As can be seen from the above, running two (or three) carburettors can have an impact on the main metering system. This is often seen as good idle, then moderate initial acceleration (as the accelerator system works), then very sluggish acceleration while the main metering system gets the engine up to speed, followed by decent performance as the main system takes over. If the venturi diameter is reduced, the pressure issue goes away, and the sluggish performance is removed. Holden recognized this when it fitted twin carburettors to the HD and HR Holden red X-2 motors – the single BXV-2 carburettor with a 1
5/32” venturi was replaced with twin BXUV-2 carburettors with smaller 1
3/32” venturis. Unfortunately, for
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the smaller capacity grey motors the BXOV-1 carburettor has no locally available smaller-venturi alternative to use when fitting twin and triple carburettors. One way however to improve the sluggish performance is to fit venturi
sleeves (sometimes referred to as venturi restrictors), Venturi sleeves
increase air speed through the venturi, getting the good vacuum signal back
to the main metering system and helping fuel atomisation. This removes the
sluggish low-down acceleration. Venturi sleeves were once anecdotally
made by an FX/FJ enthusiast to fit the BXOV-1 carburettor, though enquiry
to find the person has come up empty. Venturi sleeves however are
available for the Holley 7448 carburettor (the legendary “Holley 350”).
Redline Performance venturi sleeves are available from American Auto Parts (part number 14-35) and
Barnes Performance (part number BP14-35). It must be recognized that the sleeves are made for a
venturi diameter of 13/16” , and must be filed back (so they close up more) when fitting to the 1
1/32” BXOV-
1 venturi. The filing appears to be extensive – almost ½”needs to be removed from the circumference.
The Redline Performance venturi sleeves are 0.035” thick (~1/32”), and if gapped correctly will change a
BXOV-1 venturi diameter from 11/32” diameter to 0.96” diameter (~
31/32”).
Note also that in fitting venturi sleeves, the signal sent to the main metering system is much stronger (i.e.
the main metering jet gets “sucked on” harder. This can lead to the main metering system running rich.
When fitting venturi sleeves, the main metering jets will need to be decreased in size to account for this
(see tuning notes below).
10.6 Synchronisation
When synchronizing multiple carburettors, the aim is to make the carburettors draw in equal amounts of
air (and hence fuel). If the carburettors are not synchonised, one carburettor can run richer than the other,
leading to some of the cylinders running richer (or leaner) than others. Carburettors are normally
synchronized at idle conditions.
There are a number of ways of telling if a carburettor is synchonised. The cheapest (and often very
effective) way is to listen to the carburettor. To use this method:
Disconnect the linkage that connects one carburettor to the other.
A piece of tube (often rubber fuel hose) is inserted into the open throat of one of the carburettors, just
near the top and without blocking off the air flow.
After listening to the “hiss” of the carburettor, the hose is moved to the second carburettor and the
throttle plates of both carburettors are adjusted (via the slow idle adjusting screw for Stromberg
carburettors) until the pitch and volume of the “hiss” is the same for both carburettors. This involves a
bit of to-and-fro adjusting and backing off both throttle plates so that the “hiss” is the same from both
carburettors at the same time that the idle speed is satisfactory.
Blip the throttle to see that the carburettors come back to an equal “hiss” (worn throttle shafts can
mean that the synchronisation may take a few goes).
Once the “hiss” is equal and the resultant idle speed is OK, the idle mixture is set by adjusting both
screws evenly (for Stromberg carburettors, this is the idle needle valve).
After setting the idle mixture, the carburettors are again synchronized by listening to the “hiss”.
Reconnect the carburettor linkage, and listen to the “hiss”. If one carburettor now draws more, adjust
the carburettor linkage until it is back to roughly equal.
Bring the engine speed up to approximately 1500rpm, and again listen for the “hiss”. If one
carburettor is significantly different from the other, examine the carburettor linkage to identify the
reason why. If the reason cannot be found, the idle setting on one carburettor may be increased and
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the setting on the other decreased to allow the carburettors to be in balance under load. This is not a
great practice, and it is far preferable to balance the linkages (for example by adding washers under
some of the arms).
An alternative method is to use a carburettor synchronisation tool such as the Holley Carburetor Synchronizer shown in the lefthand image, or the Edelbrock Uni-syn tool shown in the middle image. A genuine service tool as also made by Coxhead for GMH twin carburettor balancing – see righthand image. Synchronisation tools measure the flow of air and give a reading (normally by a float tube or dial). The process for synchronisation with a tool is the same as the above listening method, though instead of getting the same “hiss” from each carburettor, you are aiming to get the same float-tube reading.
A further alternative is to use a manometer (essentially a 6‟ length of clear plastic tube ½ filled with water
or kero). The two ends of the manometer tube are connected to the carburettor above the venturi. The
vacuum in the carburettors sucks on both ends of the tube – if one carburettor has more vacuum, the
water lifts up higher in that side. This works on some carburettors that have a spare vacuum tapping, like
motorbikes. It‟s not applicable for most cars though as they do not have a vacuum tapping point. Although
it would be possible to use the 1/8” NPT port used to connect the vacuum advance line to the throttle
body, the port is located very close to the throttle plates. Turbulence in this area would not provide a
sufficiently accurate pressure measurement in order to use a manometer.
10.7 Tuning
Once the carburettors are synchronized, they may be tuned. Generally, multiple carburettors are tuned by
running the same size main metering jets and power bypass jets in all carburettors, then following the
same principles as for tuning single carburettors. Some notes which may help:
In multiple carburettor setups, it is possible that the idle system can overfeed the motor. Normally the
idle screws allow enough adjustment that the idle can be leaned up enough even though there are
two or three carburettors feeding. However, once the carburettors come off idle, the secondary idle
system comes into play. The upper two idle discharge holes are not controlled by the idle mixture
screw, but only by the size of the idle tube. The upper two idle discharge holes can thus overfeed the
motor causing it to run rich under cruise conditions (i.e. the secondary idle system is doing some of
the job of the main metering system). It is possible to down-size the main metering jets to
compensate (easier), or to down-size the idle tubes to supply less fuel. Whilst all the grey motors had
the smaller Nº. 70 drill (0.0280”) idle tube, some of the red motors had the larger Nº. 68 drill (0.0310”)
idle tube. The table in Section 5 gives some guidance as to which vehicles to hunt down to find the
smaller idle tubes. The WW Stromberg idle tube used in HR186S engines is of different design (see
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image below to the right), and is not interchangeable with the earlier B-Model idle tubes (image to
the left).
Whilst the Stromberg 97 (EE-1) idle tube is interchangeable with the B-model idle tube, I understand
that Stromberg Carburetor Ltd supply only the Nº. 70 idle tube for Stromberg 97s.
It is easier to run fixed main metering jets rather than adjustable main metering jets. Even if the jets
are “screwed out” the same as each other, it is a lot more difficult to ensure that they are “screwed
out” the same. At the extreme, it can lead to one carburettor (and hence one or more cylinders)
running rich whilst others run lean.
Main metering jets will be a lot smaller than when running a single carburettor. 46, 47 or 48 jets on a
standard to mild grey motor is a good starting point for twin or triple Stromberg carburettors (though
will need to be tuned as all engines run differently).
With two accelerator pumps running, the amount of fuel being delivered with each pump shot can be
excessive (this may be seen by hesitation during acceleration, or by a puff of black smoke when
initially accelerating). The accelerator pumps may need to be tuned as per the guidance in section
6.3 above.
Tuning multiple power bypass valves can be a challenge, as differences in the vacuum
power pistons (and manifold pressures at each carburettor) can see each of the power
bypass valves opening at different times. Some enthusiasts solve this by deleting the valves
(blocking them off) and running much richer primary metering jets. Whilst this may solve the
issue at full throttle, it will lead to a very rich “cruise” condition and is not recommended for
street use. Typically the power bypass jets will need to be reduced from Nº.67 drill to Nº.70
drill jets when running multiple carburettors. Note that whilst it appears that the HR Holden 186S
(WW-Model) power bypass jet is interchangeable with the early B-Model power bypass jets, the HR
Holden valve has two Nº.56 drill (0.0465”) holes (i.e. much larger capacity) than the B-model single-
hole power bypass valves.
Using multiple carburettors means that the flow to individual cylinders can be a lot better than a
single carburettor set-up. In twin-carburettor set-ups, the front carburettor tends to feed the front
three cylinders, whilst the rear carburettor feeds the back three cylinders. Generally, there is little
variation in fuel fed to the front and back three cylinders in this case. Triple carburettor manifolds
however tend to feed the front two cylinders from the front carburettor, cylinders three and four from
the middle carburettor and the back two cylinders from the rear carburettor. In this case, differences
in carburettors can lead to some cylinders being starved. Some enthusiasts have found that
cylinders three and four get robbed (run lean) by the front and rear cylinder pairs (which run rich).
This is the opposite of the single carburettor manifold, which tends to rob the outer cylinders. The
issue is often fixed by running richer jets in the centre carburettor of triple carburettor manifolds.
Ideally, the exhaust gas coming from the front, middle and rear cylinder pairs should be measured
with an exhaust gas analyser and the jetting in each of the three carburettors tuned to suit. However,
most exhaust manifolds do not have the ability to “tap in” to the cylinder pairs. It is possible to weld
nuts onto the exhaust manifold runners, drill them out and use them as sample points (plugging them
with a short bolt or screwed plug during normal operation). An easier (albeit less accurate) way to
tune the carburettors is to measure the exhaust manifold temperature for the cylinder pairs using an
infrared temperature gun. Cylinders which are running leaner have higher temperatures, cylinders
which are running richer have lower temperatures. Jetting can then be changed to balance the
temperatures.
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10.8 Examples of Twin and Triple Setups (Stromberg Porn)
The pictures below show some different ways of setting up linkages, fuel rails, choke and vacuum lines. I have presented the pictures in large format (at the expense of a few extra pages in this document) to help make it easier to see some of the linkages and fittings used (besides, no-one wants to be squinting at Stromberg porn). I apologise in advance for the number of pages here, though to be honest when you are putting together a linkage from scratch, every photo you can lay your hands on helps.
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11 “The Joker” Carburettor Lock
Whilst not a NASCO accessory, The
Joker carburettor lock (see image to
the right and advertising below) is a
period correct accessory for early
Holdens. The Joker was fitted
between the carburettor and the
insulating spacer, using extended
studs. By closing the key lock on The
Joker, a throttle plate closed,
preventing fuel and air supply to the
engine. The Joker also acted as a
spacer, giving rise to the claims in the
advertisement below of better
atomisation and performance
(despite the thick-edged throttle plate
being a fairly considerable
obstruction to air flow).
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12 Holden Part Numbers
The following part numbers have been taken from the Master Parts Catalogue (20 Years of Holden
Production). The list shows the separate service parts provided by GMH.
Air horn assembly 48, 50, FJ, FE, FC, FB, EK, EJ 7405154
Air horn assembly EH, HD, HR (excluding S engine) 7424552
Air horn assembly HR S engine VS10461
Air horn attaching screw and lockwasher 48, 50, FJ, FE, FC, FB, EK, EJ 7405166
Air horn attaching screw and lockwasher – long EH, HD, HR (excluding S engine) 7405167
Air horn attaching screw and lockwasher – short EH, HD, HR (excluding S engine) 7405166
Air horn attaching screw and lockwasher HR S engine 7405166
Air horn gasket 48, 50, FJ, FE, FC, FB, EK, EJ, HD,
HR (excluding S engine) 7405148
Air horn gasket HR S engine VS10462
Air horn reinforcing bar EH, HD, HR (excluding S engine) 7420240
Carburettor actuating torsion lever HR S engine 7428170
Carburettor assembly 48, 50, FJ 7402765
Carburettor assembly FE, FC, FB, EK (manual), EJ (manual) 7412264
Carburettor assembly EK (automatic), EJ (automatic) 7418661
Carburettor assembly EH 149 engine, HD 149 engine,
HR (automatic) 161 engine 7426784
Carburettor assembly EH 179 engine, HD 179 (excluding X2) engine,
HR (automatic) 186 (excluding X2 and S) engine 7426904
Carburettor assembly HD 149 engine, HR 161 engine economy carburettors 7430100
Carburettor assembly HD 179 (excluding X2), HR 186 (excluding X2
and S) engine economy carburettors 7430107
Carburettor assembly HR (manual) 161 engine 7431861
Carburettor assembly HR (manual) 186 (excluding X2 and S) engine 7431862
Carburettor assembly - front HD X2 engine, HR (automatic) X2 engine 7428498
Carburettor assembly – rear HD X2 engine, HR (automatic) X2 engine 7428502
Carburettor assembly – front HR (manual) X2 engine 7432512
Carburettor assembly – rear HR (manual) X2 engine 7432513
Carburettor assembly HR (manual) S engine 7432636
Carburettor assembly HR (automatic) S engine 7432635
Choke kick diaphragm HR S engine VS10455
Choke kick diaphragm attaching screw HR S engine VS10531
Choke kick rod assembly HR S engine VS10456
Choke kick rod retainer HR S engine VS10457
Choke kick rod vacuum hose HR S engine VS10458
Choke lever assembly 48, 50, FJ, FE, FC, FB, EK, EJ, EH, HD, HR
(excluding HR S engine) 7405122
Choke lever spring 48, 50, FJ, FE, FC, FB, EK, EJ, EH, HD, HR
(excluding HR S engine) 7405125
Choke shaft and lever assembly 48, 50, FJ, FE, FC, FB, EK, EJ, EH, HD, HR
(excluding HR S engine) 7405117
Choke shaft and lever assembly HR S engine VS10459
Choke rod HR S engine VS10444
Choke rod cotter pin HR S engine VS10454
Choke shaft bushing 48, 50, FJ, FE, FC, FB, EK, EJ 7405113
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Choke tube holder assembly 48, 50, FJ, FE, FC, FB, EK, EJ, EH, HD, HR
(excluding HR S engine) 7405247
Choke tube holder attaching screw and lockwasher 48, 50, FJ, FE, FC, FB, EK, EJ, EH,
HD, HR (excluding HR S engine) 7405167
Choke tube clamp screw 48, 50, FJ, FE, FC, FB, EK, EJ, EH, HD, HR
(excluding HR S engine) 7405127
Choke tube clamp screw nut 48, 50, FJ, FE, FC, FB, EK, EJ, EH, HD, HR
(excluding HR S engine) 7405128
Choke tube clamp screw washer 48, 50, FJ, FE, FC, FB, EK, EJ, EH, HD, HR
(excluding HR S engine) 7405121
Choke wire clamp screw 48, 50, FJ, FE, FC, FB, EK, EJ, EH, HD, HR
(excluding HR S engine) 7405124
Choke wire connector 48, 50, FJ, FE, FC, FB, EK, EJ 7405123
Choke valve assembly 48, 50, FJ, FE, FC, FB, EK, EJ, EH, HD, HR
(excluding HR S engine) 7405116
Choke valve assembly HR S engine VS10460
Choke valve attaching screw 48, 50, FJ, FE, FC, FB, EK, EJ, EH, HD, HR
(excluding HR S engine) 7405118
Choke valve attaching screw HR S engine 7405165
Dashpot HR S engine VS10451
Dashpot bracket HR S engine VS10450
Dashpot nut hexagonal jam 5/16”-24 HR S engine 124920
Dashpot screw and lock washer HR S engine 7405167
Fast idle cam 48, 50, FJ, FE, FC, FB, EK, EJ 7405250
Fast idle cam EH, HD, HR (excluding S) engines VS10248
Fast idle cam lever 48, 50, FJ, FE, FC, FB, EK, EJ 7405249
Fast idle cam lever EH, HD, HR (excluding S) engines 7424560
Fast idle cam pin 48, 50, FJ, FE, FC, FB, EK, EJ, EH, HD, HR
(excluding HR S engine) 7405111
Fast idle cam lever cotter pin (extension prong) 48, 50, FJ, FE, FC, FB, EK, EJ, EH, HD,
HR (excluding HR S engine) 7405140
Fast idle lever 48, 50, FJ, FE, FC, FB, EK, EJ 7405119
Fast idle lever EH, HD, HR (excluding S) engines 7424548
Fast idle lever attaching nut 48, 50, FJ, FE, FC, FB, EK, EJ, EH, HD, HR 7405120
Fast idle lever attaching nut washer 48, 50, FJ, FE, FC, FB, EK, EJ, EH, HD, HR
(excluding HR S engine) 7405121
Fast idle lever attaching nut washer – spring lock No. 10 HR S engine 131183
Fast idle rod 48, 50, FJ, FE, FC, FB, EK, EJ 7405161
Fast idle rod EH, HD, HR (excluding S) engines 7424553
Fast idle rod HR S engine VS10472
Fast idle rod cotter pin 48, 50, FJ, FE, FC, FB, EK, EJ 7405140
Fast idle rod cotter pin EH, HD, HR (excluding S) engines 7405140
Fast idle rod retainer HR S engine VS10471
Fast idle screw HR S engine VS10521
Float chamber baffle HR S engine VS10446
Float and lever assembly 48, 50, FJ, FE, FC, FB, EK, EJ, HD,
HR (excluding S engine) 7405112
Float and lever assembly HR S engine VS10445
Float level gauge HR S engine VS10582
Page 130 of 148
Float fulcrum pin 48, 50, FJ, FE, FC, FB, EK, EJ, HD, HR 7405156
Float fulcrum pin spring 48, 50, FJ, FE, FC, FB, EK, EJ, HD, HR 7405170
Float needle valve and seat assembly 48, 50, FJ 7405155
Float needle valve and seat assembly FE, FC, FB, EK, EJ, EH, HD, HR
(excluding S engine) 7406701
Float needle valve and seat assembly – heavy duty FE, FC, FB, EK, EJ, EH, HD, HR
(excluding S engine) 7420335
Float needle valve and seat assembly HR S engine VS10443
Float needle valve and seat gasket 48, 50, FJ, FE, FC, FB, EK, EJ, HD, HR 7405147
Gasket - flange HR S engine 7433691
Gasket – flange 48, 50, FJ, FE, FC, FB, EK, EJ 7405279
Gasket – flange EH 149 engine, HD 149 engine, HD X2 engine,
HR 161 engine, HR X2 engine 7424566
Gasket – flange EH 179 engine, HD 179 (excluding X2) engine,
HR 186 (excluding X2 and S) engine 7424567
Gasket – flange HD 179 (excluding X2), HR 186 (excluding X2 and S)
engines economy carburettors 7424566
Gasket – heat insulating EH 149 engine, HD 149 engine, HD X2 engine,
HR X2 engine 7420678
Gasket – heat insulating EH 179 engine, HD 179 (excluding X2) engine 7420679
Gasket – heat insulating HD 179 (excluding X2 and S) engine economy carburettor7420678
Gasket kit 48, 50, FJ, FE, FC, FB, EK, EJ 7405179 Gasket kit EH 149 engine, HD 149 engine, HD X2 engine,
HR 161 engine, HR X2 engine 7424290 Gasket kit EH 179 engine, HD 179 excluding X2 engine, HR 186 excluding X2 and S engines 7424535 Gasket kit HR S engine 7438608 Gasket kit HD 179 excluding X2, HR 186 (excluding X2 and S)
Engines economy carburettors 7424290 High speed bleeder 48, 50, FJ, FE, FC, FB, EK, EJ, EH, HD, HR 7405109
Idle air bleeder (No 52) 48, 50, FJ, FE, FC, FB, EK, EJ, EH 149, HD X2,
HR X2 engines 7405108
Idle air bleeder (No 53) EH 149, HD 149, HR 161 engines VS10075
Idle air bleeder EH 179, HD 179 (excluding X2), HR 186 (excluding
X2 and S) engines 7420491
Idle air bleeder (No 52) HD 149, HR 161 engines economy carburettors 7405108
Idle air bleeder channel plug 48, 50, FJ, FE, FC, FB, EK, EJ, EH, HD, HR
(excluding HR S engine) 7405110
Idle needle valve 48, 50, FJ, FE, FC, FB, EK, EJ, EH, HD, HR 7405174
Idle needle valve spring 48, 50, FJ, FE, FC, FB, EK, EJ, EH, HD, HR
(excluding HR S engine) 7405171
Idle needle valve spring HR S engine VS10438
Idle tube (No 70) 48, 50, FJ, FE, FC, FB, EK, EJ, EH 7405135
Idle tube (No 68) EH, HD, HR (excluding S) engines VS10074
Idle tube HR S engine VS10470
Idle tube conversion package EH 149 engine 7429177
Idle tube conversion package EH 179 engine 7429178
Idle vent valve EH, HD, HR (excluding S engine) 7420242
Idle vent valve stem EH, HD, HR (excluding S engine) 7420243
Page 131 of 148
Idle vent valve stem spring EH, HD, HR (excluding S engine) 7420244
Idle vent valve washer HR S engine VS10530
Insulator Assembly – heat 48, 50, FJ up to engine No. 283372 7400134
Insulator Assembly – heat FJ from engine No. U283384, FE, FC, FB, EK, EJ 7409234
Insulating spacer 48, 50, FJ, FE, FC, FB, EK, EJ, EH, HD, HR
(excluding HR S engine) 7405168
Lead ball plug 48, 50, FJ, FE, FC, FB, EK, EJ, HD, HR 7405107
Main body assembly 48, 50, FK, FE, FC, FB, EK, EJ 7405175
Main body assembly EH 149 engine (piston part No. 7406080 Group 3.788
must be used with these bodies) 7424557
Main body assembly EH 149, HD 149 HD X2, HR 161, HR X2 engines
(piston part No. 7420249 Group 3.788 must be used
with these bodies) 7420245
Main body assembly EH 179 engine (piston part No. 7406080 Group 3.788
must be used with these bodies) 7424558
Main body assembly EH 179, HD 179 (excluding X2), HR 186 (excluding
X2 and S) engines (piston part No. 7420249 Group
3.788 must be used with these bodies) 7420246
Main body assembly HD 149, HR 161 engines economy carburettors VS10188
Main body assembly HD 179 (excluding X2), HR 186 (excluding X2 and S)
engines economy carburettors 7420245
Main body assembly HR S engine VS10452
Main body attaching screw and lockwasher 48, 50, FJ, FE, FC, FB, EK, EJ, EH, HD, HR
(excluding HR S engine) 7405163
Main body attaching screw and lockwasher HR S engine VS10523
Main body attaching screw and lockwasher HR S engine 7405167
Main body channel plug 48, 50, FJ, FE, FC, FB, EK, EJ, HD,
HR (excluding S engine) 7405158
Main body channel plug HR S engine VS10526
Main body gasket 48, 50, FJ, FE, FC, FB, EK, EJ, EH, HD, HR
(excluding HR S engine) 7405143
Main body gasket HR S engine VS10433
Main discharge jet 48, 50, FJ, FE, FC, FB, EK, EJ 7400370
Main discharge jet (28-30) EH, HD, HR (excluding S) engines 740037
Main discharge jet HR S engine VS10532
Main metering jet (0.050”) 48, 50, FJ 7403431
Main metering jet (0.051”) 48, 50, FJ, FE, FC, FB, EK, EJ 7405264
Main metering jet (0.055”) EH 149, HD 149, HD X2, HR 161, HR X2 engines 7420388
Main metering jet (0.053”) EH 149, HR 161 engines (high altitude 4000-8000 ft) 7420385
Main metering jet (0.051”) EH 149, HR 161 engines (high altitude 8000-12000 ft) 7405264
Main metering jet (0.059”) EH 179, HD 179 (excluding X2) engines 7420412
Main metering jet (0.058”) EH 179, HD 179 (excluding X2), HR 186 (excluding
X2 and S) engines VS10185
Main metering jet (0.057”) EH 179 engine (high altitude 4000-8000 ft) 7424569
Main metering jet (0.055”) EH 179 engine (high altitude 8000-12000 ft) 7420388
Main metering jet (0.051”) HD 149, HR 161 engines economy carburettors 7405264
Main metering jet (0.055”) HD 179 (excluding X2), HR 186 (excluding X2 and S)
Engines economy carburettors 7420388
Main metering jet (0.053”) HR S engine VS10533
Page 132 of 148
Main metering jet (0.051”) HR S engine (high altitude 4000-8000 ft) VS10534
Main metering jet (0.049”) HR S engine (high altitude 8000-12,000 ft) VS10535
Main metering jet plug gasket 48, 50, FJ, FE, FC, FB, EK, EJ, EH, HD, HR 7405144
Nut, thick hex 5/16”-24 48, 50, FJ, FE, FC, FB, EK, EJ 143416
Nut – hex. 3/8”–24 – light (thick) EH, HD (excluding X2 engine),
HR (excluding X2 and S engines) 120369
Nut – hex. 5/16”-24 – light HR S engine 120368
Nut – hex. 3/8”-24 HD X2 engine, HR X2 engine SP1656
Plug – auto hex. head pipe 1/8” NPTF HD X2 engine, HR X2 engine 444612
Power bypass jet assembly 48, 50, FJ, FE, FC, FB, EK, EJ 7406899
Power bypass jet assembly (No. 57) EH 149 engine 7424564
Power bypass jet assembly (No. 56) EH 149 engine, HD 149 engine, HD X2 engine,
HR161 engine, HR X2 engine 7420490
Power bypass jet assembly (No. 55) EH 179 engine, HD 179 (excluding X2) engine,
HR 186 (excluding X2 and S) engine 7420747
Power bypass jet assembly (No. 54) EH 179 engine 7424565
Power bypass jet assembly (No. 65) HD 149, HR 161 engines economy carburettors 7406899
Power bypass jet assembly (No. 56) HD 179 (excluding X2), HR 186 (excluding X2 and S)
Engines economy carburettors 7420490
Power bypass jet assembly HR S engine VS10469
Pump check ball – inlet HR S engine VS10527
Pump check ball – outlet HR S engine VS10519
Pump and power bypass jet gasket 48, 50, FJ, FE, FC, FB, EK, EJ, EH, HD, HR 7405146
Pump bypass jet assembly (No. 56) 48, 50, FJ, FE, FC, FB, EK, EJ, EH, HD,
HR (excluding S engine) 7405131
Pump check ball – inlet HR S engine VS10527
Pump check ball – outlet HR S engine VS10519
Pump check valve assembly with ball 48, 50, FJ, FE, FC, FB, EK, EJ, EH, HD, HR
(excluding HR S engine) 7405136
Pump check valve plug 48, 50, FJ, FE, FC, FB, EK, EJ, EH, HD, HR
(excluding HR S engine) 7405159
Pump check valve plug gasket 48, 50, FJ, FE, FC, FB, EK, EJ, EH, HD, HR
(excluding HR S engine) 7405145
Pump gasket HR S engine VS10468
Pump lever 48, 50, FJ, FE, FC, FB, EK, EJ 7405151
Pump lever EH, HD, HR (excluding S) engines 7424551
Pump lever HR S engine VS10464
Pump lever attaching nut 48, 50, FJ, FE, FC, FB, EK, EJ 7405128
Pump lever attaching nut EH, HD, HR (excluding S) engines 7424617
Pump lever attaching washer 48, 50, FJ, FE, FC, FB, EK, EJ 7405121
Pump lever attaching washer EH, HD, HR (excluding S) engines 7424168
Pump lever attaching screw HR S engine VS10517
Pump nozzle HR S engine VS10467
Pump nozzle screw HR S engine VS10518
Pump piston and stem assembly 48, 50, FJ, FE, FC, FB, EK, EJ, HD,
HR (excluding S engine) 7405133
Pump piston and stem reducer 48, 50, FJ, FE, FC, FB, EK, EJ 7405106
Pump piston assembly HR S engine VS10449
Pump rod 48, 50, FJ, FE, FC, FB, EK, EJ, EH, HD, HR
Page 133 of 148
(excluding HR S engine) 7405160
Pump rod HR S engine VS10465
Pump rod link 48, 50, FJ, FE, FC, FB, EK, EJ, EH, HD, HR
(excluding HR S engine) 7405153
Pump rod link spring clip 48, 50, FJ, FE, FC, FB, EK, EJ, EH, HD, HR
(excluding HR S engine) 7405138
Pump rod link repair kit 48, 50, FJ, FE, FC, FB, EK, EJ 7427342
Pump rod link repair kit EH, HD, HR (excluding S) engines 7427343
Pump rod link cotter pin HR S engine 7405140
Pump stem cotter pin HR S engine 7405140
Pump stem spring 48, 50, FJ, FE, FC, FB, EK (manual), EJ (manual) 7405169
Pump stem spring EK (automatic), EJ (automatic) 7425236
Pump stem spring EH, HD, HR (excluding S engine) 7424555
Pump stem duration spring HR S engine VS10448
Pump stem duration spring washer retainer HR S engine VS10528
Pump stem duration spring washer clip HR s engine VS10529
Pump stem bottom spring HR S engine VS10447
Pump stem cotter pin 48, 50, FJ, FE, FC, FB, EK, EJ, HD,
HR (excluding S engine) 7405141
Pump strainer screen 48, 50, FJ, FE, FC, FB, EK, EJ, EH, HD, HR
(excluding HR S engine) 7405162
Pump strainer screen clip 48, 50, FJ, FE, FC, FB, EK, EJ, EH, HD, HR
(excluding HR S engine) 7405139
Repair kit – rebuild FE, FC, FB, EK (manual), EJ (manual) 7424283
Repair kit – rebuild EK (automatic), EJ (automatic) 7424284
Repair kit – major overhaul 48, 50, FJ 7405285
Repair kit – major overhaul FE, FC, FB, EK, EJ 7406879
Repair kit – major overhaul EH 149 engine, HD 149 engine, HR 161 engine 7430071
Repair kit – major overhaul EH 179 engine 7424577
Repair kit – major overhaul HD 179 (excluding X2) engine,
HR 186 (excluding X2 and S) engine 7430399
Repair kit – major overhaul HD 149, HR 161 engines economy carburettors VS10187
Repair kit – major overhaul HD 179 (excluding X2), HR 186 (excluding X2 and S)
engines economy carburettors 7430071
Repair kit HR S engine 7438609
Repair kit – major overhaul HC X2 engine VS10146
Repair kit – minor overhaul 48, 50, FJ 7425197
Repair kit – minor overhaul FE, FC, FB, EK, EJ 7425198
Repair kit – minor overhaul EH 149 engine, HD 149 engine, HR 161 engine 7424574
Repair kit – minor overhaul EH 179 engine, HD 179 (excluding X2) engine,
HR 186 (excluding X2 and S) engine 7424575
Repair kit – minor overhaul HD 179 (excluding X2), HR 186 (excluding X2 and S)
Engines economy carburettors 7424574
Repair kit – minor overhaul HD X2 engine, HR X2 engine VS10148
Slow idle adjusting screw 48, 50, FJ, FE, FC, FB, EK, EJ, EH 149, HD 149,
HD X2, HR 161, HR X2 engines 7405164
Slow idle adjusting screw EH 179, HD 179 (excluding X2), HR 186 (excluding
X2 and S) engines 7424554
Slow idle adjusting screw HD 179 (excluding X2), HR 186 (excluding X2 and S)
Page 134 of 148
Engines economy carburettors 7405164
Slow idle adjusting screw HR S engine VS10520
Slow idle adjusting screw spring 48, 50, FJ, FE, FC, FB, EK, EJ, EH, HD, HR
(excluding HR S engine) 7405172
Slow idle adjusting screw spring HR S engine VS10474
Thermostat cover assembly HR S engine VS10442
Thermostat cover screw HR S engine VS10525
Thermostat cover screw washer HR S engine VS10524
Thermostat cover gasket HR S engine VS10441
Thermostat lever and shaft assembly HR S engine VS10440
Thermostat lever HR S engine VS10439
Thermostat lever and shaft assembly washer Spring lock No6 HR S engine 131044
Thermostat lever attaching nut HR S engine 7420254
Throttle body assembly 48, 50, FJ, FE, FC, FB, EK, EJ 7405253
Throttle body assembly EH 149 engine, HD 149 engine,
HR 161 (automatic) engine 7428167
Throttle body assembly EH 179 engine, HD 179 (excluding X2) engine,
HR 186 (automatic, excluding X2 and S) engine 7428168
Throttle body assembly HR 161 (manual) engine VS10309
Throttle body assembly HR 186 (manual, excluding X2 and S) engine VS10310
Throttle body assembly HD 179 (excluding X2), HR 161, HR 186 (excluding
X2 and S) engines economy carburettor 7428167
Throttle body assembly – front carburettor HD X2 engine, HR (automatic) X2 engine VS10149
Throttle body assembly – rear carburettor HD X2 engine, HR (automatic) X2 engine VS10150
Throttle body assembly – front carburettor HR (manual) X2 engine VS10312
Throttle body assembly – rear carburettor HR (manual) X2 engine
VS10313
Throttle body assembly HR (manual) S engine VS10473
Throttle body assembly HR (automatic) S engine VS10453
Throttle body channel plug 48, 50, FJ, FE, FC, FB, EK, EJ, HD, HR (excluding X2
engine) 7405158
Throttle lever and shaft 48, 50, FJ, FE, FC, FB, EK, EJ 7405248
Throttle lever and shaft – 0.005” oversize 48, 50, FJ, FE, FC, FB, EK, EJ 7425403
Throttle lever EH 7424559
Throttle shaft EH 7424619
Throttle shaft – 0.005” oversize EH VS10250
Throttle lever HD (excluding X2) engine,
HR (excluding X2 and S) engine 7424559
Throttle shaft HD (excluding X2) engine,
HR (excluding X2 and S) engine 7428169
Throttle shaft – 0.005” oversize HD (excluding X2) engine,
HR (excluding X2 and S) engine VS10251
Throttle nut EH, HD (excluding X2) engines,
HR (excluding X2 and S) engines 7424617
Throttle valve 48, 50, FJ, FE, FC, FB, EK, EJ, EH 149 engine,
HD 149 engine, HD X2 engine, HR 161 engine,
HR X2 engine 7405173
Throttle valve EH 179 engine, HD 179 (excluding X2) engine,
HR 186 (excluding X2 and S) engine 7424556
Page 135 of 148
Throttle valve HD 179 (excluding X2), HR 186 (excluding X2 and S)
Engines economy carburettors 7405173
Throttle valve HR S engine VS10437
Throttle valve attaching screw 48, 50, FJ, FE, FC, FB, EK, EJ, EH, HD, HR
(excluding HR S engine) 7405165
Throttle valve attaching screw HR S engine VS10522
Throttle washer EH, HD (excluding X2) engines,
HR (excluding X2 and S) engines 7424618
Throttle lever and shaft assembly – front carburettor HD X engine, HR X2 engine VS10151
Shaft and pump lever assembly – rear carburettor HD X2 engine, HR X2 engine VS10152
Throttle lever – rear carburettor HD X2 engine, HR X2 engine VS10153
Throttle lever and shaft HR S engine VS10436
Vacuum power piston assembly 48, 50, FJ, FE, FC, FB, EK, EJ, EH (on EH series must
be used with carburettor assembly part Nos 7421339,
7422385 and body assembly Nos 7424557 and 7424558) 7406080
Vacuum power piston assembly EH (must be used with carburettor assembly part Nos
7406452, 7406453 and body assembly 7420245 and
7420246) 7420249
Vacuum power piston assembly HD, HR (excluding S) engines 7420249
Vacuum power piston assembly HD, HR (excluding S) engines economy carburettors VS10189
Vacuum power piston assembly HR S engine VS10466
Vent tube 48, 50, FJ, FE, FC, FB, EK, EJ 7405114
Vent tube EH, HD, HR (excluding S engine) 7424550
Volume restrictor rod EH, HD, HR (excluding S) engines 7420258
Volume restrictor rod HR S engine M35948
Page 136 of 148
13 Bendix Stromberg Part Numbers
The following part numbers have been taken from The Bendix Corporation Australia (Automotive) Pty Ltd
Carburettor and Fuel Pump Service Parts Catalogue No. PC2 issued March 1968. The list shows the
separate service parts provided by Stromberg, and should be read in conjunction with the following notes:
NOTE 1: A heavy duty viton needle and seating, part No. 2376199 is available for this carburettor.
NOTE 2: These screws also secure the air horn reinforcing bar.
NOTE 3: Supply also (1) 2376083 vacuum power piston.
NOTE 4: P21778/68 fitted from August 1964. Use major repair kit RK665 for this later setting.
NOTE 5: Used as throttle stop lever on these models. Throttle lever is 2376081.
NOTE 6: For high altitude operation use P19442/053 for 4,000-8,000ft; P19442/051 for 8,000-12,000ft.
NOTE 7: For high altitude operation use P19442/057 for 4,000-8,000ft; P19442/055 for 8,000-12,000ft.
NOTE 8: Used on carburettors stamped 23-201, 23-201A, 23-202, 23-202A. Not required on carburettors
stamped 23-201B, 23-202B.
NOTE 9: For high altitude operation use 386208-051 for 4,000-8,00ft; 386208-049 for 8,000-12,000ft.
NOTE 10: P19442-058 and P21778-68 fitted from August 1964. Use repair kit RK666 for this later setting.
Numbering is as per the Stromberg diagrams below (note these are different numberings to the Holden
diagrams given above):
Page 137 of 148
BXOV-1, BUV-2 and BXV-2 Models
Page 138 of 148
WW Models
Page 139 of 148
Part No
Vehicle
Holden 48, 50, FJ, FE, FE and early FC (1948-
1959).
Holden FC (late), FB, EK and EJ
manual transmissions (1959 - 1963).
Holden EK and EJ automatic transmissions (1961 - 1963).
Holden EH 149ci engines (August
1963 - early 1964).
Holden EH 149ci engines with manual and automatic
transmissions (early 1964 -
February 1965).
Holden EH 179ci engines with manual and automatic
transmissions (August 1963 –
early 1964).
Holden EH 179ci engines with manual and automatic
transmissions (early 1964 –
February 1965).
Holden HD 149ci economy (taxi) engines (late 1965 – April 1966) and
Holden HR, HK 161ci economy (taxi) engines (April 1966 –
1968).
Holden HD 179ci economy (taxi) engines (late 1965 –
April 1966) and Holden HR and
HK 186ci economy (taxi) engines (April 1966 – 1968).
Stamping 23-105D 23-3000 23-3001 23-3002 23-3005 23-3003 23-3006 23-3011 and
23-3022 23-3012 and
23-3021 Model BXOV-1 BXUV-2 BXV-2 BXUV-2
Specification 380228 2375000 2375002 2375003 2375007 2375005 2375008 2375017 2375018
- Major repair kit RK654 RK654A RK658 RK658 RK659 RK667 RK665
- Minor repair kit PRK654 PRK654A PRK658 PRK659 PRK658
- Gasket set ST1 ST5 - ST6 ST5
- Rebuild pack RBP1 RBP2 RBP3 -
- Choke tube (cast
in) 1
1/32” 1
3/32” 1
5/32” 1
1/32” 1
3/32”
47 Main discharge jet 385178
48 Main jet P19442-051 P19442-055 P19442-059 P19442-059
NOTE 10 P19442-051 P19442-055
82 High speed
bleeder P23985-70
85 Power jet 382880-67 382880-65 382880-56 382880-55 382880-65 382880-56
89 Slow-running jet P21778-70 P21778-70
NOTE 4 P21778-70
78 Needle and
seating 385053 2376000
NOTE 1
- Needle and
seating washer P10666
9 Lead ball (5 off) P18772
18 Vent tube P24045 386171
19 Choke valve P24046
20 Choke valve screw (2 off)
P22573
21 Choke lever and
shaft 2376088
22 Fast idle lever P24052 2376020
23 Fast idle lever nut
lockwasher 901004-K6
24 Fast idle lever nut P16571
25 Air horn attaching
screw and lockwasher (5 off)
909521-K36 909521-K36
(5) 909521-K36 (3), 909522-K36 (2)
NOTE 2
26 Air horn P24709 2376037
27 Air horn gasket P24624
29 Fast idle rod P24060 2376056
29A Fast idle rod
cotter pin 901207-K36(1) 901207-K36(2)
30 Pump stem cotter
pin P21338
31 Pump rod 385078
Page 140 of 148
32 Pump duration
spring P24287 2376017 P24102
33 Pump piston 385046
34 Fast idle cam
lever cotter pin 901207-K36
36 Pump bypass
valve P24062/2x56
37 Pump bypass valve gasket
P19448
38 Pump screen clip P23271
39 Pump screen P23270
40 Float fulcrum pin
spring P23273
41 Float and lever 382537
42 Float lever fulcrum pin
P23272
43 Main body 385051 2376082NOTE 3
2376082 2376087NOTE 3
2376087 2376210 2376082
44 Pump inlet check
valve P18144
45 Check valve plug
gasket 383080
46 Check valve plug P24678
49 Main jet plug
gasket 383079
50 Main jet plug P23902
52 Pump link clip 384391
53 Pump link 384390
56 Pump lever P21774 2376053
58 Pump lever nut
lockwasher 901004-K6 901006-K6
59 Pump lever nut 901834-K36 901624-K36
62 Throttle valve 385050 2376062 385050
63 Throttle body 385173 2376036 2376063 2376281
65 Idle needle valve P15478
66 Idle needle valve
spring P15481
67 Fast idle cam pin P23620
68 Fast idle cam
lever 385172 2376055
69 Fast idle cam 385048 2376054
71 Slow idle
adjustment screw P15456 2376174 P15456
72 Slow idle
adjustment screw spring
P15831
73 Throttle lever Part of item 86 2376051 #2376051
74 Throttle valve screw (2 off)
P20904
75 Main body and
insulating spacer gasket (2 0ff)
P24037
76 Main body
insulating spacer 384677
80 Main body screw
and lockwasher (2 off)
909551-K1
Page 141 of 148
81 Drive plug P15459 (2) P15459 (3) P15459 (2) P15459 (3)
83 Power jet gasket P19448
86 Throttle shaft 385176 2376052 2376103
87 Throttle lever nut
lockwasher - 901066-K6
88 Throttle lever nut - 901624-K36
90 Vacuum power
piston 387211 2376083 387211 2376083 2376188
94 Choke tube clamp
screw 904231-K36
95 Choke tube holder 385175
96 Choke tube clamp screw lockwasher
901004-K6
97 Choke tube clamp
screw nut 901834-K36
94-97
Choke tube holder assembled
complete with screw
385174
98 Tube holder
attaching screw and lockwasher
909522-K36
99 Manual choke lever spring
P24080
100 Manual choke
lever P24081
101 Wire clamp screw P12867
102 Valve stem
locknut
Not used
901818-K36
103 Idle vent valve 2376078
104 Idle vent valve
stem 2376079
105 Idle vent valve
spring 2376080
- Flange gasket P15022 2376066 2376064 2376066
- Air horn
reinforcing bar 2376075
- Volume restrictor
rod - 2376039
Part No
Vehicle
Holden HD (February 1965 - April 1966), HR and HK (April 1966 – 1968)
automatic transmissions, HT, HG and LC 149ci and 161ci
engines.
Holden HD 179ci engines
(February 1965 – April 1966). Holden HD
(February 1965 – April 1966), HR and HK (April
1966 – 1968), HT and HG 186ci engines with
automatic transmissions.
Holden HD (February
1965 – April 1966) 179ci
engines, Holden HD 179ci X2
engines front carburettor (February
1965 – April 1966) and HR (April 1966 –
1967) X2
Holden HD (February 1965
– April 1966) 179ci, Holden HD 179ci X2 engines rear carburettor
(February 1965 – April 1966) and HR (April
1966 – 1967) X2 engines with
automatic transmissions
Holden HR and HK (April 1966-
1968), HT, HG and LC 161ci engines
with manual transmissions.
Holden HR and HK (April 1966 –
1968), HT and HG 186ci engines with manual
transmissions.
HR 186ci X2 engines with
manual transmission
front carburettor (April 1966 –
1967).
HR 186ci X2 engines with
manual transmission
rear carburettor (April 1966 –
1967)
Page 142 of 148
engines with automatic
transmissions front
carburettor
rear carburettor.
Stamping 23-3013 and
23-3007 23-3008 and
23-3014 23-3009 and
23-3015 23-3010 and
23-3016 23-3019 23-3020 23-3024
23-3023
Model BXUV-2 BXV-2 BXUV-2 BXV-2 BXUV-2 BXUV-2 Specification 2375009 2375010 2375013 2375014 2375024 2375025 2375027 2375028
- Major repair kit RK665 RK666 RK663 RK664 RK665 RK666 RK663 RK664
- Minor repair kit PRK658 PRK659 PRK663 PRK658 PRK659 PRK663
- Gasket set ST5 ST6 ST5 ST6 ST5
- Choke tube (cast
in) 1
3/32” 1
5/32” 1
3/32” 1
5/32” 1
3/32”
47 Main discharge jet 385178
48 Main jet P19442-055 P19442-058 P19442-055
P19442/055NOTE
6
P19442/058NOTE
7 P19442/055
82 High speed
bleeder P23985-70
85 Power jet 382880-56 382880-55 382880-56 382880-55 382880-56
89 Slow-running jet P21778-68 P21778-70 P21778/68 P21778/70
78 Needle and
seating 2376000
NOTE 1
- Needle and
seating washer P10666
9 Lead ball (5 off) P18772 P18772 (6) P18772 (5)
18 Vent tube 386171
19 Choke valve P24046
20 Choke valve screw (2 off)
P22573
21 Choke lever and
shaft 2376088
22 Fast idle lever 2376020
23 Fast idle lever nut
lockwasher 901004-K6
24 Fast idle lever nut P16571
25 Air horn attaching
screw and lockwasher (5 off)
909521-K36 (3) 909522-K36 (2)
NOTE 2
909521-K36 (4) 909522-K36 (2)
NOTE 2 909521-K36 (3) 909522-K36 (2)
NOTE 2 909521-K36 (4)
909522-K36 (2)
NOTE 2
909521-K36 (3) 909522-K36 (2)
NOTE 2
26 Air horn 2376037
27 Air horn gasket P24624
29 Fast idle rod 2376056
29A Fast idle rod cotter
pin 901207-K36 (2)
30 Pump stem cotter
pin P21338
31 Pump rod 385078
32 Pump duration
spring P24102
33 Pump piston 385046
34 Fast idle cam
lever cotter pin 901207-K36
36 Pump bypass P24062/2x56
Page 143 of 148
valve
37 Pump bypass valve gasket
P19448
38 Pump screen clip P23271
39 Pump screen P23270
40 Float fulcrum pin
spring P23273
41 Float and lever 382537
42 Float lever fulcrum
pin P23272
43 Main body 2376082 2376087 2376082 2376087 2376082
44 Pump inlet check
valve P18144
45 Check valve plug
gasket 383080
46 Check valve plug P24678
49 Main jet plug
gasket 383079
50 Main jet plug P23902
52 Pump link clip 384391
53 Pump link 384390
56 Pump lever 2376053 Part of item
86 2376053 Part of item 86
58 Pump lever nut
lockwasher 901006-K6 - 901006-K6
59 Pump lever nut 901624-K36 - 901624-K36
62 Throttle valve 385050 2376062 385050
63 Throttle body 2376104 2376105 2376184 2376183 2376281 2376284 2376293 2376294
65 Idle needle valve P15478
66 Idle needle valve
spring P15481
67 Fast idle cam pin P23620
68 Fast idle cam
lever 2376055
69 Fast idle cam 2376054
71 Slow idle
adjustment screw P15456 2376174 P15456 903925-K1 P15456
72 Slow idle
adjustment screw spring
P15831
73 Throttle lever 2376051NOTE 5 Part of item
86 2376168 2376051 Part of item 86
2376168
74 Throttle valve screw (2 off)
P20904
75 Main body and
insulating spacer gasket (2 0ff)
P24037
76 Main body
insulating spacer 384677
80 Main body screw
and lockwasher (2 off)
909551-K1
81 Drive plug P15459 (3) P15459 (2) P15459 (3) P15459 (2) P15459 (1) P15459 (3)
83 Power jet gasket P19448
Page 144 of 148
86 Throttle shaft 2376103 2376193 2376192 2376103 2376193 2376192
87 Throttle lever nut
lockwasher 901006-K6 - 901006-K6 -
88 Throttle lever nut 901624-K36 - 901624-K36 -
90 Vacuum power
piston 2376083
94 Choke tube clamp
screw 904231-K36 - 904231-K36 - 904231-K36
95 Choke tube holder 385175 - 385175 - 385175
96 Choke tube clamp screw lockwasher
901004-K6 - 901004-K6 - 901004-K6
97 Choke tube clamp
screw nut 901834-K36 - 901834-K36 - 901834-K36
94-97
Choke tube holder assembled
complete with screw
385174 - 385174 -
385174
98 Tube holder
attaching screw and lockwasher
909522-K36 - 909522-K36 - 909522-K36
99 Manual choke lever spring
P24080
100 Manual choke
lever P24081
101 Wire clamp screw P12867
102 Valve stem
locknut 9901818-K36
103 Idle vent valve 2376078
104 Idle vent valve
stem 2376079
105 Idle vent valve
spring 2376080
- Flange gasket 2376066 2376064 2376066 2376064 2376066
- Air horn
reinforcing bar 2376075
- Volume restrictor
rod 2376039
-
Front and rear carburettors connecting coupling
- 020059 - 020059
-
- Carburettor
actuating throttle lever
- - 2376081 -
Part No
Vehicle
Holden HR, HK, HT and HG 186S
engines with manual
transmissions.
Holden HR, HK, HT and HG 186S
engines with automatic
transmissions.
Stamping 23-201A and
23-201B
23-202, 23-202A and 23-
202B Model WW WW
Page 145 of 148
Specification 381205 381206 - Major repair kit RK696 - Gasket set 381505
31 Main discharge jet
(2 off) 388562
32 Main jet (2 off) 386208-053NOTE 9
27 High speed
bleeder (2 off) P23985-70
24 Power jet 382454
26 Slow-running jet
(2 off) 387183
21 Pump jet P24594
57 Needle and
seating 388592
58 Needle and
seating washer P10666
1 Choke kick diaphragm assembly
389190
2 Choke kick rod 389291
3 Choke kick rod
retainer 389188
4 Vacuum hose 389193
5 Air horn screw
and lockwasher (4 off)
909521-K36
6 Choke lever and
shaft 483504
7 Choke valve screw (2 off)
P20904
8 Choke valve 387129
9 Air horn 389890
10 Air horn gasket 389456
11 Fast idle lever 389293
12 Fast idle lever nut
lockwasher 901004-K6
13 Fast idle lever nut
P16571
14 Lead ball P18772
15 Pump lever 387131
16 Pump lever
fulcrum screw 387200
17 Pump rod 389884
18 Pump rod and
piston cotter pin (3 off)
901207-K36
19 Vacuum power
piston 386723
20 Pump nozzle
screw 388643
22 Pump nozzle
gasket P24668
23 Pump outlet check ball
P17030
25 Power bypass jet
gasket P19448
Page 146 of 148
28 Fast idle rod
retainer 387124
29 Fast idle rod 389294
30 Main body lead
ball (3 off) P18772
33 Metering jet plug
gasket (2 off) 383079
34 Main metering jet
plug (2 off) 386210
35 Main body gasket 388563
36 Throttle body 483688 483689
37 Slow idle screw
spring 387388
38 Slow idle screw 387387
39 Fast idle screw 387531
40 Throttle lever and
shaft 388198
41 Throttle valve screw (4 off)
P23956
42 Throttle valve P24172
43 Throttle valve P24172
44 Idle needle valve
spring (2 off) P18710
45 Idle needle valve
(2 off) P15478
46 Throttle body
screw and lockwasher (2 off)
386094
47 Throttle body
screw and lockwasher (2 off)
909522-K36
48 Thermostat lever
nut 901818-K36
49 Thermostat lever nut lockwasher
901002
50 Thermostat shaft
lever 386799
51 Thermostat lever
and shaft 386981
52 Thermostat cover
washer (3 off) P23932
53 Thermostat cover
screw (3 off) 389883
54 Thermostat cover
gasket 386797
55 Thermostat cover
assembly 483509
56 Drive plug (2 off) 385937
59 Choke rod 386801
60 Choke rod cotter
pin 901199-K1
61 Float and lever 386154
62 Float fulcrum pin P23272
63 Float fulcrum pin
spring P23273
64 Float chamber 387583
Page 147 of 148
baffle
65 Pump inlet check
ball P22322
66 Pump bottom
spring 388672
67 Pump duration
spring 386089
68 Spring retainer
washer P22046
69 Spring clip washer P22045
70 Pump piston
assembly 483666
71 Idle vent washer 388476
72 Choke kick
diaphragm screw (2 off)
386804
73 Dashpot nut 901713-K7
74 Dashpot bracket 388202
75 Dashpot bracket
screw and lockwasher (2 off)
909522-K36
76 Dashpot 386498
- Main body assembly
389887
- Hot air restrictor
wire 2376367NOTE 8
Page 148 of 148
14 Contacts
The businesses listed below have not reviewed or approved the information above, nor are they the sole
source of materials – I have listed them here as I have found them to be professional sources of early
Holden Stromberg parts and/or information.
Carburettor Service Company
Address: 240 Parramatta Road Burwood, NSW 2134 Australia
Telephone: (02) 97474066
Facsimile: (02) 97474803
Email: [email protected]
Internet: www.carburettorservice.com.au
Rocket Industries
Address: 40 Huntingwood Drive Huntingwood, NSW 2148 Australia
Telephone: (02) 88251944
Facsimile: (02) 88251922
Email: [email protected]
Internet: www.rocketind.com
Stromberg Carburetor
Address: Unit 2, Seven Acres Business Park, Newbourne Road,
Waldringfield, Suffolk IP12 4PS, England
Telephone: (+44) 1473 811700
Email: [email protected]
Internet: http://www.stromberg-97.com
American Auto Parts
Address: Unit 2, 22 Rowood Road Prospect, NSW 2148 Australia
Telephone: (02) 9769 0655
Facsimile: (02) 9769 0633
Email: [email protected]
Internet: https://www.americanautos.com.au
Speco Thomas Pty Ltd
Address: 1B Levanswell Road Moorabbin, VIC 3189 Australia
Telephone: (03) 95557244
Facsimile: (03) 95532841
Email: [email protected]
Internet: http://www.speco.com.au