AHSANULLAH UNIVERSITY OF SCIENCE

AND TECHNOLOGY (AUST)

ME-4203: AUTOMOBILE ENGINEERING

Dr. Abu Hamja 
Assistant Professor, MPE 

Acknowledgment:
Fazlar Rahman; Asst. Prof.; AUST
 ME-4203 (Automobile Engineering)
Engine Types and Classification (Chapter ‐12):
 Automotive engines can be classified according to (12‐1): 
o Number of cylinders.
o Arrangement of cylinders.
o Arrangement of valves and valves trains.
o Type of cooling.
o Number of strokes per cycles (two or four).
o Type of fuel burned.
o Method of ignition.
o Firing order.
o Reciprocating or rotary.
 Number and Arrangement of Cylinders (12‐2): Figure 12‐1
o In a row (in line)
o In two rows or banks set at an angle V (V‐type)
o In two rows or banks opposing each other (flat, pancake or 
horizontally opposed type).
o Like spokes on a wheel or radial type.

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 ME-4203 (Automobile Engineering)
Engine Types and Classification (Chapter ‐12):
 Number and Arrangement of Cylinders (12‐2): 

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 ME-4203 (Automobile Engineering)
Engine Types and Classification (Chapter ‐12):
 Three cylinders engines (12‐3):
 Two or three cylinders in line engines are also popular in some country used in 
small and light weight vehicle.
 Normally camshaft and crankshaft are hollow to save weight, cylinder blocks 
are made of aluminum.
 V belt from cranks shaft drive the alternator and water pump. Camshaft driven 
by toothed timing belt and distributor driven directly at the end of camshaft.

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 ME-4203 (Automobile Engineering)
Engine Types and Classification (Chapter ‐12):
 Three Cylinders Inline Engines (12‐4):

Figure: Inline 3 cylinder engine

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 ME-4203 (Automobile Engineering)
Engine Types and Classification (Chapter ‐12):
 Four cylinders in line engines (12‐4): Fig 12‐3; 12‐4; 12‐5; 12‐6 & 12‐7
o Four cylinders can be arranged 
 In a line: Fig 12‐3; 12‐4
 Four cylinders are installed in a row.
 Camshaft is in the cylinder block and driven by timing chain 
from the crankshaft.
 Engine with this type of valve train is often called an 
overhead‐valve (OHV) engine or pushrod engine.
 In a V (V‐type): Fig 12‐6
 Four cylinders are arrange in two rows in an angle 90 or 60 
degrees.
 Crankshaft has only two connecting‐rods journals. Connecting 
rods from opposing cylinders are attached to the same 
journal.

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 ME-4203 (Automobile Engineering)
Engine Types and Classification (Chapter ‐12):
 Four Cylinders Inline Engines (12‐4): Fig 12‐3; 12‐4; 12‐5; 12‐6 & 12‐7
o Four cylinders can be arranged 
 In a V (V‐type):
 Engine is difficult to balance with counterweights on the
crankshaft to overcome the roughness & vibration a balance
shaft is used in the engine which turns opposite of crankshaft.
 Opposed (flat or pancake):
 The Volkswagen Beetle has an opposed (flat or pancake) air
cooled engine. It mounted in the rear of the car to drive the
rear wheel.
 Liquid cooled flat‐four engine is installed in the front of the
car to drive the front wheel.
 Sprockets and toothed timing belts turn the two camshafts.
 Compact size. Normally used in light weight vehicle and
motorcycles.

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 ME-4203 (Automobile Engineering)

Engine Types and Classification (Chapter ‐12):
 Four Cylinders Inline Engines: 

Fig. 12‐3: Inline 4 cylinder engine with camshaft in the   
cylinder block.

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 ME-4203 (Automobile Engineering)

Engine Types and Classification (Chapter ‐12):
 Four Cylinders Inline Engines: 

 Oil pump has separate drive.
 Valve operate by tappets.
 Camshaft driven by sprocket  and timing 
belt.
 Chrysler Corporation engine.

Fig. 12‐4: 4‐Cylinder Inline engine.

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 ME-4203 (Automobile Engineering)

Engine Types and Classification (Chapter ‐12):
 Four Cylinders Inline Engines: 

 4 valve per cylinder.
 Two overhead camshaft.
 Valve tappets and no pushrod.
 Sprockets and a chain drive
operates camshaft.
 One camshaft for intake valve & 
other one for exhaust valve.
 General Motors Corporation 
engine.

Fig. 12‐4: 4‐Cylinder Inline engine.

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 ME-4203 (Automobile Engineering)
Engine Types and Classification (Chapter ‐12):
 Four Cylinders Inline Engines (12‐4):

Figure: Inline 4 cylinder engine

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 ME-4203 (Automobile Engineering)
Engine Types and Classification (Chapter ‐12):
 Four Cylinders  Inline Engines (12‐4):

Figure: Inline 4 cylinder engine
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 ME-4203 (Automobile Engineering)
Engine Types and Classification (Chapter ‐12):
 V‐4 Engines (12‐4):

Figure:  V4 Engine
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 ME-4203 (Automobile Engineering)
Engine Types and Classification (Chapter ‐12):
 V‐4 Engines (12‐4):

Figure:  V4 Engine
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 ME-4203 (Automobile Engineering)
Engine Types and Classification (Chapter ‐12):
 Four Cylinders V‐4 Engines: 

 Only  two connecting‐rod journals.
 Each connecting‐rod attached with 
two cylinders.
 Reduce roughness and vibration, 
engine uses a balanced shaft.
 Balance shaft turn opposite 
direction of crankshaft.
 Ford Motor Company of Germany.

Fig. 12‐4: 4‐Cylinder V4 engine.
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 ME-4203 (Automobile Engineering)
Engine Types and Classification (Chapter ‐12):
 Opposed Four Cylinders Engines:

Figure:  Opposed 4 Cylinder Engine
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 ME-4203 (Automobile Engineering)
Engine Types and Classification (Chapter ‐12):
 Five Cylinders Engines (12‐5):

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 ME-4203 (Automobile Engineering)
Engine Types and Classification (Chapter ‐12):
 Opposed Four Cylinders Engines:

Figure:  Opposed 4 Cylinder Engine
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 ME-4203 (Automobile Engineering)
Engine Types and Classification (Chapter ‐12):
 Four Cylinders Flat or Opposed Engines: 

 Two camshaft, one in each side.
 Camshaft operated by sprockets 
and timing belt.
 Liquid cooled Subaru of America, 
Inc engine.

Fig. 12‐4: 4‐Cylinder Flat engine.

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 ME-4203 (Automobile Engineering)
Engine Types and Classification (Chapter ‐12):
 Five Cylinders Inline Engines (12‐5): Figure 12‐8; 12‐9
o Several manufactures used five cylinder Inline engines. Mercedes
makes five‐cylinder Inline diesel engine.
o Mounted in longitudinally or transversely.

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 ME-4203 (Automobile Engineering)
Engine Types and Classification (Chapter ‐12):
 Five Cylinders Engines (12‐5):

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 ME-4203 (Automobile Engineering)
Engine Types and Classification (Chapter ‐12):
 Five Cylinders Inline Engines (12‐5):

 Five cylinder SI engine.
 Used in four wheel drive car.
 Engine mount longitudinally.
 4 valves per cylinder total 20 
valves.
 Two camshaft, valve operates 
by bucket tappets.
 Audi of America, Inc engine.

Fig. 12‐8: Five cylinder double‐overhead camshafts.

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 ME-4203 (Automobile Engineering)
Engine Types and Classification (Chapter ‐12):
 Five Cylinders Inline Engines (12‐5):

 Five cylinder turbocharged SI 
engine.
 Used in front wheel drive car.
 Engine mount transversely.
 Separate oil supply line to 
turbocharged bearing.
 Direct spray of cooling oil to the 
underside of piston.
 Thermostatically controlled  oil 
cooler system.
 Oil‐cooled engine.
 Volkswagen of American, Inc.

Fig. 12‐8: Five cylinder turbo charged engine.

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 ME-4203 (Automobile Engineering)
Engine Types and Classification (Chapter ‐12):
 Six Cylinders Inline Engines (12‐6): Figure 12‐10; 12‐11; 12‐12
o Six cylinder engine can be Inline, V‐type or Opposed.

 6 cylinder inline SI engine.
 Engine use pushrod.
 Camshaft in the cylinder 
block.
 Oil pump mounted side of 
camshaft and driven by gear 
of the camshaft.
 Chrysler Corporation 
engine.

Fig. 12‐10: Inline 6 cylinder engine.

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 ME-4203 (Automobile Engineering)
Engine Types and Classification (Chapter ‐12):
 Six Cylinders Inline Engines (12‐6): Figure 12‐10; 12‐11; 12‐12

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 ME-4203 (Automobile Engineering)
Engine Types and Classification (Chapter ‐12):
 Six Cylinders Inline Engines (12‐6): Figure 12‐10; 12‐11; 12‐12

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 ME-4203 (Automobile Engineering)
Engine Types and Classification (Chapter ‐12):
 Six Cylinders V6 Engines (12‐6): Figure 12‐11; 12‐12
o V6 engine has two rows of three cylinders at angle 60 or 90
degrees.
o Some V6 engine has double‐over‐head camshafts.

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 ME-4203 (Automobile Engineering)
Engine Types and Classification (Chapter ‐12):
 Six Cylinders V6 Engines (12‐6):

 4 camshafts two in each cylinder head.
 Camshafts driven by timing belt.
 Camshafts are in the cylinder block.
 Valves operated by pushrods.
 Ford Motor Company engine.

Fig. 12‐10: Inline V6 engine.

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 ME-4203 (Automobile Engineering)
Engine Types and Classification (Chapter ‐12):
 Six Cylinders V6 Engines (12‐6): Figure 12‐11; 12‐12

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 ME-4203 (Automobile Engineering)
Engine Types and Classification (Chapter ‐12):
 Six Cylinders Opposed Engines (12‐6): Figure 12‐13
o Ferrari, Porsche and Subaru make six‐cylinder Opposed engines
with overhead camshafts.

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 ME-4203 (Automobile Engineering)
Engine Types and Classification (Chapter ‐12):
 Six Cylinders Opposed Engines (12‐6): Figure 12‐13
o Flat opposed six cylinder engine shown below used in Honda
motorcycles.

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 ME-4203 (Automobile Engineering)
Engine Types and Classification (Chapter ‐12):
 Six Cylinders Opposed Engines (12‐6):

 Single overhead camshaft in 
each cylinder.
 Subaru of America engine.

Fig. 12‐13: Opposed 6 cylinder engine.

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 ME-4203 (Automobile Engineering)
Engine Types and Classification (Chapter ‐12):
 V8 Engines (12‐7): Figure 12‐14
o Engine has single crankcase and camshaft. Crankshaft has four
crankpins.
o Connecting rods from opposing cylinders are attached to a single
crankpin i.e. each crankpin attached two connecting rods.
o Normally chain from the crankshaft drives an idler sprocket which
drives the timing chain that turns the camshafts.
o Cylinders might have more than 2 valves.
o V8 engine used in high performance and commercial vehicle.

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 ME-4203 (Automobile Engineering)
Engine Types and Classification (Chapter ‐12):
 V8 Engines (12‐7):

Figure: 2013 Bentley Continental GT V8

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 ME-4203 (Automobile Engineering)
Engine Types and Classification (Chapter ‐12):
 V8 Engines (12‐7):

Figure: 2013 Bentley Continental GT V8

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 ME-4203 (Automobile Engineering)
Engine Types and Classification (Chapter ‐12):
 V8 Engines (12‐7):

 Camshaft in cylinder block.
 Overhead valves with 
pushrods.
 Timing chain drive the 
camshaft.
 Four valves in each cylinder.
 Ford Motor Company 
engine.

Fig. 12‐14: V‐8 engine

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 ME-4203 (Automobile Engineering)
Engine Types and Classification (Chapter ‐12):
 Twelve and Sixteen Cylinder Engines (12‐8):
o Used in passenger cars, buses, trucks and industrial equipment.
o Cylinders are most often in two banks (V or opposed). Some
designs have three banks (W type) or 4 banks (X type).
o BMW, Ferrari, Jaguar and Lamborghini use 16 cylinders engine.

Figure: Bugatti, 16 cylinders 1500 hp, 261 mph top speed, $2.6 million

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 ME-4203 (Automobile Engineering)
Engine Types and Classification (Chapter ‐12):
 Twelve and Sixteen Cylinder Engines (12‐8):

Figure: Bugatti Veyeron; W16 type engine.

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 ME-4203 (Automobile Engineering)
Engine Types and Classification (Chapter ‐12):
 Twelve and Sixteen Cylinder Engines (12‐8):

Bugatti Chiron; 2016 Geneva Auto Show; Priced $2.6 million; Speed of 261 
mph or 420 kph; Top speed 500 kph (311 mph); 16 cylinders;  1500 hp.

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 ME-4203 (Automobile Engineering)
Engine Types and Classification (Chapter ‐12):
 Radial Engine:
o Engine cylinders are installed radially at a certain angular space.
o Radial engine also known as star engine.
o Radial engines are used in aircraft, motorcycle, tanks and also in
racing car.

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 ME-4203 (Automobile Engineering)
Engine Types and Classification (Chapter ‐12):
 Radial Engine:

41
 ME-4203 (Automobile Engineering)
Engine Types and Classification (Chapter ‐12):
 Radial Engine:

42
 ME-4203 (Automobile Engineering)
Engine Types and Classification (Chapter‐12):
 Arrangement of Valve and Valve Trains (12‐9): 
o There are several different arrangements of valve and valve trains.
Differences that affect engine classification include:
 Location of camshaft.
 Nature of drive of camshaft.
 Type of valve train.
 Number of valves per cylinder.
o Location of camshaft: Figure 12‐14, 12‐15
 Camshaft is either in the cylinder block or on the cylinder head.
o Nature of drive of camshaft: Figure 12‐16
 Camshafts are driven by timing gears, sprockets and timing 
chain, or sprockets and toothed timing belt.
 Some engines use a combination of timing chain and timing 
belt to drive the camshafts.

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 ME-4203 (Automobile Engineering)
Engine Types and Classification (Chapter‐12):
 Arrangement of Valve and Valve Trains (12‐9): 
o Types of Valve Train: Figure 12‐17; 12‐17A, 12‐17C
 Overhead camshafts and camshaft in block or overhead 
camshaft valve.
 In each type rotating cam lobe actuates the valve train to open 
the valve.
 Camshaft in the cylinder block may also drive the ignition 
distributor.  A shaft from the distributor drives the engine oil 
pump.
 An eccentric on the camshaft operates the mechanical fuel 
pump.
o Number of valves per cylinder:
 Some engines have more than two valves per cylinder. Some
engines have three, four five or even six valves in each cylinder.
 Additional valves in cylinders improves the volumetric
efficiency and allow more burned gases exit more freely.

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 ME-4203 (Automobile Engineering)
Engine Types and Classification (Chapter‐12):
 Arrangement of Valve and Valve Trains (12‐9): 

Timing Gear Timing Chain

Figure: Timing Gear and Chain to drive camshaft in cylinder block

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 ME-4203 (Automobile Engineering)
Engine Types and Classification (Chapter‐12):
 Arrangement of Valve and Valve Trains (12‐9): 

Figure: Timing belt and chain camshaft in cylinder head.

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 ME-4203 (Automobile Engineering)
Engine Types and Classification (Chapter‐12):
 Arrangement of Valve and Valve Trains (12‐9): 

Fig. 12‐17: Types of valve trains.

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 ME-4203 (Automobile Engineering)
Engine Types and Classification (Chapter‐12):
 Arrangement of Valve and Valve Trains (12‐9): 

Figure: Timing Chain with guide to drive camshaft in cylinder head.

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 ME-4203 (Automobile Engineering)
Engine Types and Classification (Chapter‐12):
 Arrangement of Valve and Valve Trains (12‐9): 

Figure: Timing Belt with tensioner to drive camshaft in cylinder head.

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 ME-4203 (Automobile Engineering)
Engine Types and Classification (Chapter‐12):
 Arrangement of Valve and Valve Trains (12‐9): 

Figure: Timing Belt with tensioner to drive camshaft in cylinder head.

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 ME-4203 (Automobile Engineering)
Engine Types and Classification (Chapter‐12):
 Arrangement of Valve and Valve Trains (12‐9): 

Figure: Overhead camshaft
in cylinder head

Figure: Camshaft in engine block with pushrod and rocker arm.

Figure: Overhead Camshaft with bucket tappet.

Figure 12‐18: Oil‐pump, Ignition distributor and fuel pump drive.

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 ME-4203 (Automobile Engineering)
Engine Types and Classification (Chapter‐12):
 Engine Rotation and Cylinder Numbering (12‐10): 
o Both SI and CI engines, crankshaft rotates in a counterclockwise
direction, as viewed from the flywheel or output end of the
engine.
o Cylinder number 1 usually assigned to the farthest cylinder from
the output end of the crankshaft. This is used in both
longitudinally or transversely installed engine.
o In V‐type or opposed‐cylinder engines, the cylinders may be
numbered in sequence in each bank. Number is 1 is assigned to
the farthest cylinder from the output end of crankshaft.
o Some manufacturers often refer to right‐hand or left‐hand location
of parts that are near or on the engine. Cylinder bank and
accessory locations are right or left when the engine is viewed
from the output end.

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 ME-4203 (Automobile Engineering)
Engine Types and Classification (Chapter‐12):
 Engine Rotation and Cylinder Numbering (12‐10):

Fig. 12‐19: Cylinder numbering. 

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 ME-4203 (Automobile Engineering)
Engine Types and Classification (Chapter‐12):
 Engine Firing Order (12‐11): Figure 12‐19
o The firing order is the sequence in which the cylinders deliver their
power strokes. It is designed to the engine.
o The crankpin and camshaft arrangement determine the firing
order.
o In most engine, firing order evenly distributes the power strokes
along the crankshaft.
o Most engine designs avoid firing two cylinders, one after another
at the same end of the crankshaft.
o Firing order of same type of engine may vary from manufacture to
manufacturer.
o Two firing order of 4 cylinders engines are 1‐3‐4‐2 and 1‐2‐4‐3.
o Main purpose of firing order is to reduced the torsional vibration
in the crankshaft and distribute power uniformly.
o Inline six cylinders engine firing impulse occurs every 120 degrees
of crankshaft revolution and firing order is 1‐5‐3‐6‐2‐4.

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 ME-4203 (Automobile Engineering)
Engine Types and Classification (Chapter‐12):
 Engine Firing Order (12‐11): Figure 12‐19

Fig. 12‐20: Engine firing order and cylinder numbering.

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 ME-4203 (Automobile Engineering)
Engine Types and Classification (Chapter‐12):
 Engine Firing Order (12‐11): Figure 12‐19

58
 ME-4203 (Automobile Engineering)
Engine Types and Classification (Chapter‐12):
 Classification by Cooling (12‐12):
o Almost all automotive engines are liquid‐cooled.
o Volkswagen Beetle engine and some others are air cooled. Air
cooled engines has fins in the cylinders that carry excess heat to
the atmosphere.
o Some light weight two or one cylinder engines uses air‐cooled
system. Example motor cycles, power lawn mowers etc.

59
 ME-4203 (Automobile Engineering)
Engine Types and Classification (Chapter‐12):
 Classification by Cycles (12‐13): Figure 12‐21A; 12‐21B
o Piston engines operate on either two‐stroke cycle or four‐stroke
cycle.
o 4 stroke engines have one power stroke in each revolution of
crankshaft and 2 stroke engines have two power strokes in each
revolution of crankshaft.
o Two stroke engines use port instead of valves.
o Two stroke has more pollution and less thermal efficiency than 4
strokes engine.
o Two stroke engines are light weight and compact.
o Two stroke engines are used motorcycles, scooters and other light
weight utility equipments.

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 ME-4203 (Automobile Engineering)
Engine Types and Classification (Chapter‐12):
 Classification by Cycles (12‐13):
o Two‐stroke engine:

61
 ME-4203 (Automobile Engineering)
Engine Types and Classification (Chapter‐12):
 Classification by Cycles (12‐13):
o Four‐stroke engine:

62
 ME-4203 (Automobile Engineering)
Engine Types and Classification (Chapter‐12):
 Classification by Fuel (12‐14):
o SI engine uses gasoline or gasohol which is blend of gasoline and
alcohol.
o Some SI engine uses LPG (liquified Petroleum gas) or CNG
(Compressed natural gas) especially in buses and trucks.
o CI engine uses light oil called diesel fuel.
o Some car engines are designed for flexible fuel i.e. it runs on
gasoline or alcohol blend fuels.
 Adiabatic Engines (12‐15):
o In conventional engine, a significant amount of heat leaves the
engine through lubricating system, cooling system and with
exhaust gas without converting useful mechanical work.
o The hotter engine runs with high efficiency but increasing of
engine temperature is limited by the melting temperature of
materials.
o So adiabatic diesel engine is under development which uses parts
with ceramic coating to withstand at high temperature.
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 ME-4203 (Automobile Engineering)
Engine Types and Classification (Chapter‐12):
 Adiabatic Engines (12‐15): Ceramic coated engine parts.

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 ME-4203 (Automobile Engineering)
Engine Types and Classification (Chapter‐12):
 Adiabatic Engines (12‐15): Ceramic coated engine parts.

Fig. 12‐22: Ceramic‐coated parts in a diesel engine (Ford Motor Company).

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 ME-4203 (Automobile Engineering)
Engine Types and Classification (Chapter‐12):
 Rotary Engines (12‐16): 
o In rotary engines, rotors spin to produce power. There is no need
to conversion of reciprocating motion of piston to rotary motion.
o There are two types of rotary engine: Gas‐turbine engine and
Wankel engine.
o Gas turbine engines are successfully used in airplanes, helicopters
and electric power generating system. It operates almost at
constant speed and it does not do well in automotive vehicle.
o Gas turbine engine delay in acceleration after driver depresses the
throttle. Gas turbine runs at very high speed with high operating
temperature and it required very expensive materials to construct.

66
 ME-4203 (Automobile Engineering)
Engine Types and Classification (Chapter‐12):
 Rotary Engines (12‐16): Gas turbine engine

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 ME-4203 (Automobile Engineering)
Engine Types and Classification (Chapter‐12):
 Rotary Engines (12‐16): Gas turbine engine

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 ME-4203 (Automobile Engineering)
Engine Types and Classification (Chapter‐12):
 Rotary Engines (12‐16): Gas turbine engine

Figure: Racing car with gas turbine engine (1967); Indianapolis Motor
Speedway; Pratt & Whitney gas turbine.

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 ME-4203 (Automobile Engineering)
Engine Types and Classification (Chapter‐12):
 Wankel Engine (12‐17): Figure 12‐23; 12‐24
o Wankel engine has rotors that spin in an oval chambers shaped like
a flat figure 8.
o It is a rotary combustion (RC) engine operates as four stroke cycle
engine.
o Engine output power is directly rotary motion instead of
converting reciprocating motion to rotary motion.

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 ME-4203 (Automobile Engineering)
Engine Types and Classification (Chapter‐12):
 Rotary Engines (12‐16): 

Fig. 12‐23: Two rotors Wankel engine (Mazda Motor of America, Inc.)

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 ME-4203 (Automobile Engineering)
Engine Types and Classification (Chapter‐12):
 Rotary Engines (12‐16): 

Fig. 12‐23: Sequence of action of rotor for single rotation.
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