theory and design of automotive...

THEORY AND DESIGN OFAUTOMOTIVE ENGINES

Prof. B Dinesh Prabhu P E S C E Mandya

Syllabus• I - Introduction

1. General - History, Types of Power Plant, Principle of operation & Classification of Engines


2. Two Stroke & Four Stroke Engines;Principles of Engine Operation (SI & CI),Scavenging - Systems, Theoretical Processes…, Valve/ Port Timing…,Merits & Demerits…,scavenging pumps

Syllabus…• II - Engine Components

– Classification/Types,– Function,– Materials,


– Materials,– Constructional Details,– Design and– Manufacturing Processes

of The Engine Components

Syllabus…3. Cylinder Head, Cylinders & Liners4. Piston, Rings & Pin5. Connecting Rod6. Crank Shaft


6. Crank Shaft7. Flywheel, Camshaft8. Valve & Valve Mechanism9. Crank case10.Manifolds

Chapter 1General

Historical development of automobilesTypes Of Power PlantTypes Of Power Plant

Principle of Engine OperationClassification Of Engines

“History is very valuable,because it is the combination of

the hard work & sacrifices that brilliant


people made to forge theworld that we live in.”

- Anonymous

History•Automobiles Through the Years

Since originated on late 1800s,Changed and Developed in response to

-Consumer Wishes,


-Consumer Wishes,-Economic Conditions, and-Advancing Technology

Current designs continue to reflect economic awareness, although many different markets exists

History…•4,000 Years ago

Used for Transportation in India•15th Century

Portuguese & Chinese Created Wheel


Portuguese & Chinese Created Wheel that Turned Under its Own Power

•1600Small Steam-Powered Engine Models developed

Cugnot Steam Tractor•1769-First Automobile-By Nicolas Cugnot

Three-wheeled steam-powered vehicleSpeed ≈ 3.2 km/h (2mph)

Had to stop every 20min


Had to stop every 20minto build up fresh head of steam

Few Records• 1801 Heavy steam automobiles introduced in

England• 1802 Steam powered coach journeyed 160km

(100mi)• Mid 1800-England-extensive network of steam


• Mid 1800-England-extensive network of steam coach lines

• 1830 Steam carriages used for first omni bus service in London

• 1906 Stanley steamer established world land speed record 205.44km/h(121.573mph)

Internal - Combustion Engine• 1860 One-cylinder engine, kerosene- fuel.• 1864 Two-cylinder gasoline engine• 1876 Otto built four-stroke gas engine2-stroke engines accomplish the same steps, but


2-stroke engines accomplish the same steps, but less efficiently & with more exhaust emissions.

• 1885 Gasoline-powered engine mounted onto bicycle-motorcycle &

• 1887 First car- included steering tiller & 4-speed gearbox - Daimler & Maybach

• In 1885 German engineer Gottlieb Daimler mounted an engine of his own design into a wood-framed vehicle.

• The vehicle had 4 wheels, including 2 round stabilizing wheels.

• World’s first


• World’s firstmotorcycle.

Early Car• 1885 First practical car (gasoline car) – By Karl Benz

Incorporating differential drive & other components


components

Design Improvements• 1891 Peugeot automobile paced 1,046-km

(650-mi)• 1894 Instead of installing engine under

seats, front-mounted engine under hood


seats, front-mounted engine under hood along with clutch, gears, & separate construction of the chassis designed

• 1899 Fiat in Italy – began building cars

Horseless Carriage• 1893

-By Duryea brothers -Original Horseless Carriage - -America’s First Internal Combustion Motor Car


-Henry Ford built IC Engine• 1896- Henry Ford used

engine power on bicyclesteered by tiller

Early Electric Cars• 1800s Electric engines (quiet, slow speed

& not scaring to horse & people), enjoyed great popularity

• 1899 Electric car designed & driven to set


• 1899 Electric car designed & driven to set a record of 105.8810 km/h(65.79 mph)

• Most electric cars-top speed 48km/h (30mph), could go only 80km (50mi) before recharging

20th Century• For many years commonly used power sources

- steam engines, gasoline engines and electric motors.

• Gasoline powered engines became universal


• Gasoline powered engines became universal choice to have – longer trips & faster speeds

• 1902 First American car (Locomobile)had 4-cyinder,water cooled, front mounted gasoline engine – verysimilar in design to most cars today

Shaping Up!• 1906 Gasoline powered cars had

- a hood covered front mounted engine- two kerosene/acetylene lamps (head lights)- fenders covering wheels & step up platforms


- fenders covering wheels & step up platforms- passenger compartment-behind engine

• 1911 Electric self starter introduced to replace hand crank to start engineElectric head lights introduced

Ford• 1903 First automobile – Ford Model A

each year new Ford models B, C...• 1908-1927 – 15 million cars of Model T

adopting innovative


adopting innovativeassembly linemethod

Affordable for anaverage wage earner!

Assembly of a Model TTwo workers mount an engine into the chassis of a Ford Model


of a Ford Model T that was put together at earlier points on the assembly line.

Luxury Automobiles(For comfort & style rather than speed)• 1909 Rolls-Royce Silver Ghost

-quiet 6-cylinder engine, leather interior, folding windscreens & aluminum body.


folding windscreens & aluminum body.

Desgin Improvements• 1920 Synchromesh Transmission

(for easy gear shifting), improved carburetors,shatterproof glass,


shatterproof glass, heaters, balloon tires, 4 - wheel hydraulic brake systems, pressed-steel wheels, andmechanically operated wind shield wipers incorporated

Vintage Models Made to individual specifications• 1929 – Graham Paige DC Phaeton

8-cylinder engine & aluminum body


Improvements• 1930 -1937

Large Engines (12-16 cylinder) &large -luxurious BodiesIndependent front suspension, (made big


Independent front suspension, (made big cars more comfortable )more reliable braking systems,higher-compression engines (for more hp)

• 1936 - Mercedes introduced World’s first Diesel Car

Convenient, Reliable& Inexpensive

•1937 Pontiac De Luxe Sedanroomy interior rear hinged back door

suited to the needs of families


suited to the needs of families

Improvements• 1940 Automatic transmission, sealed-beam

headlights, and tubeless tiresStudebaker Champion two-door sedan


“Car For The People”• 1949 A combination of look and economy

that remained popular for more than four decades.


decades.

VW Beetle

“Car For The People”


Volkswagen “Beetle” With a rear-mounted engine and rounded, bug like shape, appealed to buyers seeking utilitarian good looks, easy serviceability, and fuel efficiency. The classic Beetle became the best-selling car of all time, with more than 21 million sold.

VW New Beetle In early 1998 Volkswagen put the first “New Beetle” on the American market

New Features• 1950 Air conditioning

electrically operated car windowsseat adjusters.


seat adjusters.change over from the 6-volt to the12-volt ignition system, for better engine performance and more reliable operation of electrical accessories.Power steering & Power Brakes!

PowerfulHigh-performance Cars

• 1957 Mercedes-Benz 300SL-Gullwingcompact & stylized230kmh(144mph)


230kmh(144mph)-Door opens upwardLike gull’s wings

• 1957 Cadillac El Dorado convertibleconsumers loved the look, demanded fins of increasing size

Consumers Loved The Look


of increasing sizeuntil 1960s

Improvements•1960 American cars-built Small, Increased

Engine Size & Horse Power Heating and ventilating systems became standard equipment.


became standard equipment.Automatic transmissions, power brakes & power steering-widespread.Styling prevailed over practicality!

•1970 Catalytic converters introduced to reduce exhaust emissions.

•1964 - Mustang Ford’s best early sales success since introduction of Model T.

popular characteristicssmall, fast design,

“Muscle Car”


small, fast design,excellent handling,powerful engine &distinctive look.

Advances in Technology•1980 Digital speedometer & electronic

prompts to service parts-Sporty cars & family mini vans-Better engine control & use of


-Better engine control & use of innovative types of fuel

•1981 On-board computer to monitor engine performance

-A solar-powered vehicle, traveled 3,000 km (1,864 mi) in Australia in six days.

Modern Cars• 1992 MR-2 Turbo T-bar Toyota

aerodynamically shaped, light & compact


New Technologies• 1997 Gas-Electric Hybrids-Toyota Prius

four-seat hybrid electric vehicle (HEV)first HEV- Japan


Better-smarter•1990s Pollution control laws adopted•1996 EV1 all electric car – first sold by GM

- Redesigned, quieter Diesel engines by Volkswagon – used in passenger cars!


Volkswagon – used in passenger cars!- Engines run on Hydrogen tested

• Expanded use of computer technology, development of stronger & lighter materials & research on pollution – produce better-smarter automobiles

Computer control!•1990s Computer control of automobile systems

In modern cars, CPU -manages overall engine performance. Microprocessors regulating other systems share data with the CPU


data with the CPU Computers manage F/A mixture ratios, ign.timing, &

emission levels, adjust antilock braking & traction control systems, control air conditioning, heating, sound system & information displayed in dash board

New Technologies•1980s The notion that a car would “talk” to

its driver was science fiction; by the 1990s it had become reality.

•1990s Onboard navigation - By using the


•1990s Onboard navigation - By using the satellite-aided global positioning system (GPS), a computer in the automobile can pinpoint the vehicle’s location within a few meters

New Technologies…• The onboard navigation system uses -

electric compass, digitized maps, a display screen showing location of vehicle relative to intended destination


intended destinationAfter mentioning, computer locates destination & directs driver, offering alternative routes if neededAlso GPS system helps in emergency situations to locate & direct the concerned

New Technologies…• Cars equipped with computers and cellular

phones can link to Internet to obtain constantly updated traffic reports, weather information,route directions and other data


route directions and other data• Built-in computer systems may be used to

automatically obtain business information over Internet and manage personal affairs while driving

Looking Ahead• Devises to

-reduce driver errors and poor driving habits.-prevent intoxicated drivers from starting their vehicles.-Anti-collision systems with sensors and


-Anti-collision systems with sensors and warning signals-slow the vehicle if it is following another vehicle too closely-warn drivers when another vehicle is in their “blind spot.” Courtesy – Microsoft Encarta

Types Of Power Plant • An Engine is a device which transforms one

form of energy into another form.• Most Engines convert thermal energy into

mechanical work &therefore they are called Heat Engines.


Heat Engines.• Heat Engine is a device which transforms the

chemical energy of a fuel into thermal energy & utilizes this thermal energy to perform useful work.

• Thus thermal energy is converted to mechanical energy in a Heat Engine.

Heat Engines


Classification of Heat Engines


Heat Engines• Of the various types of heat engines,

the most widely used ones are

Ø Reciprocating internal combustion engine,


Ø Reciprocating internal combustion engine,Ø Gas turbine andØ Steam turbine

Advantages Reciprocating I C Engine • Mechanical simplicity and improved power

plant efficiency (absence of heat exchangers)• All its components work at an average temp.


• All its components work at an average temp.which is much below the maximum temp. of the working fluid in the cycle. Therefore, very high working fluid temperatures can be employed resulting in higher thermal efficiency.

• Higher thermal efficiency can be obtained with moderate maximum working pressure of the fluid in the cycle

• Weight of power ratio is less than that of the

Advantages…


• Weight of power ratio is less than that of the steam turbine plant

• It has been possible to develop reciprocating internal combustion engines of very small power output with reasonable thermal efficiency and cost.

Disadvantages• Problem of vibration caused by the

reciprocating components. Considering all the above factors the

reciprocating internal combustion engines


reciprocating internal combustion engines have been found suitable for use in automobiles, motor-cycles and scooters, power boats, ships, slow speed aircraft, locomotives and power units of relatively small output.

Cross Section of a SI Engine


Basic geometry ofreciprocating IC EngineVc Clearance,Vd Displaced, and


Vd Displaced, andVt Total cylinder volumesTC (TDC) top dead centreBC (BDC) bottom dead centre

2-Stroke Operating Cycle


Engine Classifications


Engine Classifications…1.Application.2.Basic engine design


Engine Classifications…3. Working cycle4. Valve or port

design & location.


(a) Cross, (b) Loop, (c) Uniflow Scavenging(c)

5. Fuel6. Method of mixture preparation.7. Method of ignition8. Combustion chamber design.

Engine Classifications…


8. Combustion chamber design.9. Method of load control.10.Method of cooling.

References:• Microsoft Encarta• Britanica Encyclopedia• Theory & Practice in IC Engines By C F Taylor


• Theory & Practice in IC Engines By C F Taylor• Fundamentals of I C Engines-J B Heywood• Internal Combustion Engines-Ganesan• Internal Combustion Engines-M L Mathur & S P

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