This document discusses internal combustion engines and their classification. It begins by explaining the basic components and functioning of internal combustion engines, including the four-stroke spark ignition engine and four-stroke compression ignition engine. It then classifies engines based on factors like number of cylinders, cylinder arrangement, thermodynamic cycle, type of fuel and cooling system. The document also discusses engine components like pistons, connecting rods, crankshafts and valves. It provides diagrams to illustrate the engine cycles and classifications. In conclusion, it briefly discusses alternative power sources for vehicles like electric, solar, fuel cell and hybrid technologies.

1. Automotive Engineering
A.J.Infant Jegan Rakesh M.E.,(PhD)
Assistant Professsor
Department of Mechanical Engineering
Karpagam Institute of Technology
Coimbatore

5. o Internal combustion engine
needs fuel, ignition and
compression in order to run
o Burns fuel and air in enclosed
space
o Produces hot burned gases
o Allows heat to flow to cold
outside air
o Converts some of this heat into
useful work
Internal Combustion Engine

6. Nicolaus August Otto
Born June 10, 1832
Died January 26, 1891
Gas-Motor Engine
Patent No. 4315
Inducted 1885
o Inventor of the four-stroke
spark-ignition internal
combustion engine
o In 1876 Otto built an engine
in which air-fuel mixture
could be compressed and
ignited by a spark
Petrol Engine

7. Rudolf Diesel
(1858 - 1913)
Oil Engine
German
Patent No. 67207
Inducted 1919
o Inventor of the four-stroke
Compression-ignition internal
combustion engine
o In 1893 Diesel was issued a
patent for a proposed engine, in
which air would be compressed so
much that the temperature would
far exceed the ignition
temperature of the fuel
.
Diesel Engine

9. Based on Configuration
Inline Engines:
The cylinders are arranged in a
line, in a single bank.
V Engines:
The cylinders are arranged in two
banks, set at an angle to one another.
Flat Engines:
The cylinders are arranged in two
banks on opposite sides of the
engine

10. IC Engine Classification
o Number of cylinders
1. Single-cylinder
2. Multi-cylinder
o Arrangement of the cylinders
1. In-line cylinders
2. V-shaped cylinders
3. Opposed cylinders
4. Radial cylinders
o Thermodynamic cycle
1. Otto cycle
2. Diesel cycle

11. IC Engine Classification
o Type of fuel used
1 Petrol engine
2 Diesel engine
o Type of cooling system
1. Air-cooled
2. Water-cooled
3. Liquid-cooled
o Stroke of the engine
1. Four-stroke engine
2. Two-stroke engine
3. Rotary engine (Eg. Wankel engine and Gas
Turbine)

12. IC Engine Classification
o Application of the engine
1. Constant speed engine
2. Variable speed engine
o Types of ignition system
1. Spark-ignition
2. Compression-ignition
o Firing Order
1. 1-3-4-2 or 1-4-3-2 (for 4-cylinder engine)
2. 1-5-3-6-2-4 (for 6-cylinder engine)
3. 1-5-4-2-6-3-7-8 (for V-8 engine)

13. o Stroke 1: Fuel-air mixture introduced into cylinder through
intake valve
o Stroke 2: Fuel-air mixture compressed
o Stroke 3: Combustion (roughly constant volume) occurs and
product gases expand doing work
o Stroke 4: Product gases pushed out of the cylinder through the
exhaust valve
Four stroke Spark Ignition (SI) Engine
Compression
Stroke
Power
Stroke
Exhaust
Stroke
A
I
R
Combustion
Products
Ignition
Intake
Stroke
FUEL
Fuel/Air
Mixture

14. Four stroke Spark Ignition (SI) Engine - Working

15. o Stroke 1: Air is introduced into cylinder through intake valve
o Stroke 2: Air is compressed
o Stroke 3: Combustion (roughly constant pressure) occurs and
product gases expand doing work
o Stroke 4: Product gases pushed out of the cylinder through the
exhaust valve
Four stroke Compression Ignition (CI) Engine
Compression
Stroke
Power
Stroke
Exhaust
Stroke
A
I
R
Combustion
Products
Intake
Stroke
Air
Fuel Injector

16. Four stroke Compression Ignition (CI) Engine - Working

17. Two stroke Spark Ignition (SI) Engine
o Stroke 1: Fuel-air mixture is
introduced into the cylinder and is
then compressed, combustion
initiated at the end of the stroke
o Stroke 2: Combustion products
expand doing work and then
exhausted
o Power delivered to the crankshaft on
every revolution

18. Two stroke Spark Ignition (SI) Engine - Working
Intake (“Scavenging”)
Compression Ignition
Exhaust
Expansion
Fuel-air-oil
mixture
Fuel-air-oil
mixture
Crank
shaft
Reed
valve
Exhaust
Port*
Transfer
Port*

19. Two stroke Compression Ignition (CI) Engine

20. Camshaft
Intake valve
Rocker arm
Piston
Connecting rod
Crankshaft
Oil pump
Exhaust valve
Carburetor
Crank sprocket Oil pickup
Timing belt
Cam sprocket
Air cleaner
Timing belt
tensor
Engine Anatomy

21. o A movable part fitted into a
cylinder, which can receive
and transmit power
o Through connecting rod,
forces the crank shaft to
rotate
Piston

22. o Four stroke: Three rings Top two are
compression rings (sealing the
compression pressure in the cylinder)
and the third is an oil ring (scrapes
excessive oil from the cylinder walls)
o Two Stroke: Two Rings Both the
rings are Compression rings
Piston Rings

23. o Attaches piston (wrist-pin)to the crank shaft (conn. Rod caps)
Connecting Rod

24. o Converts up and down or reciprocating motion into circular or
rotary motion
Crankshaft

25. o Minimum Two Valves pre Cylinder
o Exhaust Valve lets the exhaust gases escape the combustion
Chamber. (Diameter is smaller then Intake valve)
o Intake Valve lets the air or air fuel mixture to enter the
combustion chamber. (Diameter is larger than the exhaust
valve)
Valves

26. o Cam Shaft: The shaft that has
intake and exhaust cams for
operating the valves
o Cam Lobe: Changes rotary
motion into reciprocating
motion
Camshaft

27. o Valve Springs: Keeps the valves Closed
Valve Springs

28. o Attached to the crankshaft
o Reduces vibration
o Cools the engine (air cooled)
o Used during initial start-up
o Transfers power from engine
to drivetrain
Flywheel

29. o It provides the means of
ignition when the gasoline
engine’s piston is at the end
of compression stroke, close
to Top Dead Center(TDC)
o The difference between a
"hot" and a "cold" spark plug
is that the ceramic tip is
longer on the hotter plug
Spark Plug

30. Cylinder Head
o Part that covers and encloses
the Cylinder
o It contains cooling fins or
water jackets and the valves
o Some engines contains the
cam shaft in the cylinder head

31. o Foundation of the engine and
contains pistons, crank shaft,
cylinders, timing sprockets and
sometimes the cam shaft
Engine Block

32. Engine Operating Cycle

33. Valve Timing Diagram

34. Valve Timing Diagram – SI Engine

35. Valve Timing Diagram – CI Engine

36. Port Timing Diagram – SI Engine

37. o For proper combustion the ratio of the mass of air to the mass
of fuel in the cylinder must be roughly 15
o An IC engine is basically an air engine, the more air you get
into the cylinder, the more fuel you can burn, the more power
you get out
o Vary throttle position - Maximum intake pressure (and power)
achieved at wide-open-throttle (WOT) minimum at idle
Power Regulation

38. Power Regulation Methods
o Basic methods:
1. Manifold pressure
2. Air mass flow rate
3. Throttle position
o Engine Control Unit (ECU) activates the fuel injector solenoid
for a duration corresponding to measurement

39. o In spark ignition engines the air
and fuel are usually mixed prior to
entry into the cylinder
o Initially a purely mechanical
device known as a carburetor was
used to mix the fuel and the air
o Most modern cars use electronic
fuel-injection systems
Fuel Air Mixing

40. Electronic Fuel Injection

41. Basic Fuel Injection System

42. Multi-point Fuel Injection (MPFI) - Working

43. Gasoline Direct Injection (GDI) Engine
o Fuel is injected directly into
the cylinder during the intake
stroke or the compression
stroke
o High pressure injector
required, 5-10 Mpa
o Need bowl in piston design to
direct the fuel spray towards
the spark plug

44. Diesel Fuel Injection System
o With diesel engines fuel is sprayed directly into the cylinders
power is varied by metering the amount of fuel added (no
throttle)
o Diesel fuel injection systems operate at high-pressure, e.g., 100
Mpa
o fuel pressure must be greater than the compression pressure
o need high fuel jet speed to atomize droplets small enough for
rapid evaporation

45. Diesel Fuel Injection System
o Traditional Diesels high pressure produced locally within the
injector
o Latest Diesels use high pressure common rail with solenoid
actuated injectors

46. Common Rail Direct Injection
o Injection quantity, firing order and injection timing is controlled
by ECU(Electronic Control Unit)
o Variable start of injection
o Possibility of Pilot injection, Main injection, and Post injection
o Matching of injection pressure to the operating made

47. o These devices are used to increase the power of an IC engine
by raising the intake pressure and thus allowing more fuel to
be burned per cycle
o Knock or autoignition phenomenon limits the amount of
precompression
o Superchargers are compressors that are mechanically driven
by the engine crankshaft and thus represent a parasitic load
Supercharger and Turbocharger

48. o Positive displacement compressors: piston, Roots, and screw
o Most common is the Roots compressor – pushes air forward
without pressurizing it internally
o Dynamic compressor has a rotating element that adds
tangential velocity to the flow which is converted to pressure
in a diffuser
o Most common is the radial, or centrifugal type
Supercharger

49. o Turbochargers couple a compressor with a turbine driven by the
exhaust gas
o The compressor pressure is proportional to the engine speed
o Compressor also raises the gas temperature, so aftercoolers are
used after the compressor to drop the temperature and thus
increase the air density
Turbocharger

50. o Heat Transfer
 Conduction
 Convection
 Radiation
o Types of cooling systems
 Air cooling system
 Water cooling
 Liquid cooling system
o Heat Losses
 Radiant loss – 9%
 Output – 25%
 Exhaust loss – 33%
 Cooling system loss – 33%
Engine Cooling

51. Cooling System

52. o It reduces friction between moving parts which lessens both
wear and heat
o It acts as a coolant removing heat from the metal of the
engine
o It carries dirt and wear particles away from moving parts
cleaning the engine
o It seals the combustion chamber between piston ring and
cylinder wall
o It acts as a shock absorbers and it cushioning the engine parts
o These jobs keep the engine running smoothly and efficiently
Lubrication System

53. Lubrication System

54. Turbocharger

55. Where the turbocharger is located ?

56. Turbocharger Layout

57. Turbocharger Parts

58. Turbocharger cut-section
Turbo compressor
blades

59. Turbocharger working

63. • The figure expresses very well the
competition which batteries and fuel
cells face as vehicle power sources.
• The best power plant is one which has
characteristics which are up and to the
right in the figure.
• The best batteries fail by a significant
amount to match the specific power of
internal combustion piston engines or
gas turbines.

64. • They are even less attractive from the
standpoint of specific energy.
• Experimental batteries show promise in
improved specific energy but not to the
point of matching internal combustion
engines.
• Fuel cells do not appear attractive from
the standpoint of specific power, but they
do have desirable energy characteristics,

65. • The observation can be made that no
known battery or fuel cell system can
come close to matching the internal
combustion engine in terms of power
and energy, or expressed another way,
performance and range.
• Batteries are heavy, bulky, and costly.

66. • Fuel cells suffer from the same problems, and
additionally as Figure shows, the low power
levels limit top speeds and acceleration .
• These type power plants are low on
emissions, but as is frequently pointed out,
use of battery powered vehicles may just
transfer the emissions from the vehicle on the
road (internal combustion engine) to a fossil
fueled recharging station in the case of the
battery powered vehicle.

67. • The efficiency of a battery system is
lower than that of a conventional engine
when use of a central recharging power
station is considered.
• Efficiencies of fuel cell-electric drive
systems are remarkably high.

68. • The fuel requirements of the fuel cell are
reasonable for low power systems.
• The fuel needed for recharging batteries,
of course, is whatever is used at central
electric power generating plants, normally
fossil fuel, and possibly in the future,
nuclear fuel.
• These power plants use no lubricant.

75. The California Air Resources Board
(CARB) has told car manufacturers
in America that by the year 1998, 2%
of vehicles lighter than
3750lb(1700kg about the weight of
an average saloon car) must be zero
emission vehicles.
At the moment the only type of
vehicle that can do this is an electric
vehicle, or an EV for short.

76. • Although there are no direct emissions
from an electric vehicle, most of the
power that it uses comes from fossil
fuels burnt in power stations.
• Using electric vehicles means that
power stations will have to produce
more energy.
That means more pollution.
SO WHY USE THEM?

77. Why Encourage People to Use Them?
• Using electric vehicles is a step towards
decreasing air pollution to a great
extent.
• The use of electric cars and delivery
vans could make the air in cities much
easier to breathe by reducing fumes
and smog.
• Why is this?

78. • With the use of alternative power
sources such as Hydroelectric, Wind,
Solar, Wave and Tidal energies using
electric cars will make a lot more sense
than it does at the moment, as the use
of cars will then not indirectly produced
any harmful emissions.
• Until these alternative power sources
are used it is likely that the electric
vehicle will only benefit the state of air
pollution in the cities.

79. Why aren't people using electric vehicles now?
There are many reasons for this, the main ones
are given below:
• Fuels burnt in internal combustion engines
contain more energy for a given weight than the
batteries used by electric vehicles
• Conventional vehicles can go a lot further on a
full onboard fuel supply
• Conventional vehicles are faster than electric
vehicles

80. • Not all countries experience
problems with severe air pollution
• Only a few companies make electric
vehicles, very few of them sell any.
• All these problems are being worked
on at the moment though and there
have been some very good ideas for
solutions.

81. • As is often the case though things are
not going very quickly at the moment
the main problem is the amount of
energy As is often the case though
things are not going very quickly at the
moment the main problem is the
amount of energy that can be held
within batteries.
• Other things that effect the performance
of electric vehicles are the weight of the
vehicle, the vehicle aerodynamics and

82. Solar Powered Vehicle
Advantages
• Uses renewable energy source
• Uses photovoltaic cells to trap Solar energy
• Zero emission vehicle
Disadvantages
• Technology still in the nascent stage
• Quantum of energy obtained is very less

83. Fuel Cell Powered Vehicle
Advantages
• Renewable source of energy
• Near Zero emission levels
Disadvantages
• Technical constraints
• Expensive technology
• Storage problems

84. Electric Car
Advantage
• Zero Emission Levels
Disadvantages
• High Recharge Time
• Limited Range
• High Weight of Batteries
• Very High Cost

85. Hybrid Vehicle Technology

86. Hybrid Car
A hybrid car is combination of two or more
technologies that are combined to reduce
the overall disadvantages of the system and
improve performance.

87. A hybrid electric vehicle is one that uses both
an internal combustion engine and an electric
motor as its prime movers
Hybrid Electric Car

88. Types of Hybrid Vehicle
• Series Hybrid
• Parallel Hybrid

89. Generator
IC Engine
Power Control
Bus
Motor
Wheels
Battery
Series Hybrid Car

91. Series Hybrid Configuration
Advantages
• Simple to design
• Simple Control system
Disadvantages
• Low Reliability
• Mechanical Efficiency Low

92. Modes of Operation of a Series
Hybrid
• ZEV Mode
• Charging Mode
• Regenerative Mode

93. Generator
IC Engine Coupling Device
Motor
Wheels
Battery
Parallel Hybrid Car
Control
System

95. Parallel Hybrid
Advantages
• High Reliability
• High Mechanical Efficiency
Disadvantages
• Complex Control System
• Torque Coupler Required

96. Modes of Operation of a Series
Hybrid
• ZEV Mode
• Hybrid Mode
• Charging Mode
• Regenerative Mode

97. Components of a Hybrid Vehicle
•A small size IC Engine
•An electric prime mover (DC Series motor / AC
Induction Motor)
•A transmission system to the wheels
•A device for coupling the IC Engine and motor.
•A control system for the hybrid configuration (The
electronic hardware)
•A set of high-capacity batteries

98. FLEXIBLE ETHANOL FUEL
VEHICLE TECHNOLOGY

99. Some design and operation options appear to
be possible with the HEVs now being developed
✓ Regenerative braking capability, which helps
minimize the energy lost when driving.
✓ Engine is sized to average load, not peak load, which
reduces the weight of the engine.
✓ Fuel efficiency is greatly increased, while emissions
are greatly decreased.
HEVs can be operated using alternative fuels, therefore
they need not be dependent on fossil fuels.

100. • 20% OF THE WORLDS ENERGY CONSUMPTION IS
FOR MOBILITY IN ROAD SECTOR
• BY 550 MILLION AUTOMOBILES USING
NON-RENEWABLE PETROLEUM PRODUCTS.
• YEAR 2010 ABOUT 1.1 BILLION AUTOMOBILES
• UNREGULATED EMISSION TO INCREASE BY
ABOUT 65%
• DUE TO LARGE SCALE USE OF FOSSIL FUELS
IN THE MOBILITY SECTOR

101. INDEGENOUS PRODUCTION 33 M.TONNES
ANNUAL CONSUMPTION
GROWTH
8 %
CURRENT CONSUMPTION 100 M.TONNES
IMPORT 67 M.TONNES
COST OF IMPORT AT CURRENT
PRICE
Rs. 80,000 Crores
PETROLEUM USED IN
TRANSPORTATION SECTOR
80 %
Indian Petroleum Statistics

102. S.no Particulars Gasoline Diesel Ethanol Methanol
1 Specific Weight 0.75 0.83 0.79 0.795
2 Calorific Value
KJ/KG
43950 42970 26780 19665
3 Stoichiometric air –fuel ratio by weight 14.9 14.5 9.0 6.4
4 Boiling Temp. - C 30 -180 150 - 360 78.0 64.8
5 Calorific value of Stoichiometric mixture –
KJ/KG of mixture
2836 2772 2678 2658
6 Latent heat of vaporization –KJ/KG 335 - 418 544 - 795 904 1109
7 Self Ignition temp -C - About 300 557 575
8 Cetane Number 25 45 - 52 8 3
9 Octane Number (Motoring) 88 5 - 15 90 92
10 Transition Energy –MJ 0.25 0.25 0.30 0.30
Properties of Different fuels

103. TABLE I : COMPARISON OF FUEL PROPERTIES
Property Methanol Ethanol Gasoline E85
Chemical Formula CH3OH C2H5OH C4 to C12 Chains -
Octane No. (R+M)/2 100 98-100 86-94 96
Lower heating Value 8570 11500 18500 12500
(Btu/lb.)
Litre Equivalent 1.8 1.5 1 1.4
Km/Litre as
Compared to Gasoline 55% 70% 100% 72%

104. Fuel Tank Size 1.8 1.5 1 1.4
RVP(psi) 4.6 2.3 8-15 6-12
Air/Fuel Ratio 6.45 9 14.7 10
Vehicle Power 4% 5% Standard 3-5%
more more more

105. PREVIOUS WORK ON ETHANOL
Multi-cylinder
1) Spark Ignition Engine
1a) Four stroke automotive neat or blends
1b)Two stroke s.I.Engine neat or blends
2) Compression Ignition Engine
2a) Single cylinder
2b) Multi cylinder - Automotive (i) Diesel Ethanol
Dual fuel mode
(ii) Additive

106. ADVANTAGES OF ETHANOLAS FUEL
Higher Octane number enables the use of higher
compression ratios and hence higher thermal efficiencies
Enables lean burn operation, better combustion lower CO
and particle emission levels
Higher latent heat of vaporization increases engine overall
efficiency due to reduced heat loss, less tendency to knock
4 to 10 % higher torque and power
(Cont.)

107. 30 % lower carbon monoxide emission
However we get 20% lower mileage, because of low
calorific value
Aldehyde emission is more but can be controlled
using Platinum Paladium converters

108. ➢ GENERAL MOTORS CORPORATION
➢ FORD
➢ DAIMLER-CHRYSLER CORPORATION
➢ HONDA
➢ MITSUBISHI MOTORS CORPORATION
➢ MAZDA
➢ NISSAN
➢ HYUNDAI
PROMINENT FFV MANUFACTURES

109. Fuel Economy City : 13 MPG
Fuel Economy Highway : 18 MPG
Drive : Front Wheel
Engine Size : 3.3 L

113. CONCLUSIONS
1.There is a strong case for considering Ethanol as an alternative
fuel in transportation sector in India.
2. Technology is available for enhancing efficient production of
Ethanol from a number of sources.
3. To start with we can adopt E10 ( 10% Ethanol and 90%
gasoline) fuel.
4. The Government, the Automobile Industry, the Sugar
Industry, the Ethanol Industry and the Oil Industry should
jointly evolve a comprehensive Ethanol Fuel Program for India.
Such a program is to be implemented in a phased and in a
sustainable manner.

114. 5. The Government and Industries should encourage
Research and Technical Institutions to participate in R&D
Programs like the 2000 Ethanol Vehicle Challenge in USA.
6. We can start working on advanced design of FFV so that
larger quantities of Ethanol can be utilized when they are
available in our Country.
7. Form the Ethanol Coalition in India to make
recommendations.

115. One liter of petrol or one liter of diesel or I Cubic meter of
CNG/LPG burnt in engine is lost for ever.
WE WILL NEVER GET IT BACK.
Not with Ethanol.
Ethanol is a renewable fuel.
As long as we can grow sugarcane, we will continue to get
Ethanol year after year.

116. Possible gaseous fuels are:
• H2
• CNG
• LPG

117. Hydrogen as automotive fuel
• It is the least polluting fuel.
• But the problem is the safety.
• So hydrogen has to be tamed properly.

118. CNG as automotive fuel
• As NG is lighter than air it will escape and will not lie
on the ground.
• From the safety point of view this is a better fuel.
• Switching to CNG will reduce particulate matter and
hydrocarbon emission significantly.
• Problem is CNG is expensive to distribute and store.
• Require compression to about 200 bar.

119. • Both Bangladesh and Pakistan are piloting
CNG vehicles.
• Bajaj Auto in India has developed CNG
powered three wheelers.
• They use four-stroke engines.
• Bi-fuel operation is also possible but
expensive to manufacture.
• The long term viability of CNG vehicles
depends on favourable legislative and
regulatory atmosphere.

120. • For converting to natural gas, to make
economic sense, the retail price of CNG
needs to fall by 60% of the cost of the fuel
being replaced.
• Without this promotion of CNG vehicle cannot
be sustainable.
• In India it will be difficult to keep CNG prices
much lower than gasoline prices because
large scale import are involved.

121. • If market price are reflected the
economics of CNG vehicles will become
less favourable than they are today.
• Therefore, greater amount of insight in
assessing a CNG vehicle program is a
must.

122. • LPG as an automotive fuel
• LPG is a mixture of
(i) Propane
(ii) Butane
(iii) Butene

123. • This fuel is easy to distribute and store than
CNG.
• The fuel gets liquified at a pressure of 4 to 15
bars.
• LPG is much plainer automotive fuel than
gasoline.
• If it is to be used in two-stroke engines
lubrication problems are to be attended to.

124. • LPG contains fewer highly reactive
hydrocarbons compared to gasoline.
• However, this increases emissions and
lower the knock limited compression ratio.
• This diminishes the engine performance.

125. • LPG three-wheelers are used widely in
Thailand.
• Fueling vehicles with LPG as of now is illegal
in India.
• This situation is likely to change in the near
future.
• While not as good as CNG, LPG has superior
antiknock characteristics compared to
gasoline.