This document provides an introduction and overview of key automobile engine components. It begins by defining an automobile and describing different vehicle types classified by purpose, capacity, fuel used, number of wheels, and drive type. It then discusses the main internal combustion engine components including the cylinder, cylinder block, cylinder head, piston, piston pin, connecting rod, and crankshaft. For each component, it provides a brief definition of its function and materials typically used.

1. Automobile Engineering-
Introduction and Engine
Components
By
Dr.D.Thandapani

2. Automobile Engineering
An automobile is a self propelled vehicle used for
the transportation of goods and passengers.
A self propelled vehicle is that in which power
required for the propulsion is produced within.
Types / Classification of Vehicles Automobiles
1. Purpose:
a. Passenger vehicles – Car, Bus, Jeep
b. Goods vehicles – Truck
c.Special purpose vehicles –
Dumper,BullDozer,Mobile crane,Forklift,Loader

3. 2. Capacity:
a. Light Motor Vehicle – Car ,Jeep
b. Heavy Motor Vehicle – Bus, Truck
3. Fuel used:
a. Petrol vehicles – Scooter, Motor cycle,
car, Jeep
b. Diesel vehicles _ Car, Bus, Truck, Tractor
c. Electric cab vehicles _ Battery bike,
battery Truck, Fork lift
d. Steam type vehicles _ Steam road roller
e. Solar type vehicles _ Solar car

4. 4. Wheels:
a. Two wheelers _ Scooter, Motor cycle,
Moped
b. Three wheelers _ Autorickshaw,
Tempo
c. Four Wheelers _ Car, Jeep
d. Six Wheelers _ Truck, Bus
5. Drive of the Vehicles:
a. Left hand Drive
b. Right hand Drive
c. Front wheel drive
d. Real wheel drive
e. All wheel /4 wheel drive

5. Engine Locations

6. Rear-wheel-drive Front-wheel-drive

7. Four Wheel Drive 4X4

8. Drive Shaft

9. CHASSIS FRAME AND BODY
Introduction of Chassis Frame:
Chassis is a French term and was initially used to denote
the frame parts or Basic Structure of the vehicle. It is the
back bone of the vehicle. A vehicle with out body is called
Chassis.
The components of the vehicle like Power plant,
Transmission System, Axles, Wheels and Tyres,
Suspension, Controlling Systems like Braking, Steering
etc., and also electrical system parts are mounted on the
Chassis frame. It is the main mounting for all the
components including the body.
So, it is also called as Carrying Unit.

10. The following main components of the Chassis are
1.Frame: it is made up of long two members called side
members riveted together with the help of number of cross
members.
2.Engine or Power plant: It provides the source of power
3. Clutch: It connects and disconnects the power from the
engine fly wheel to the transmission system.
4. Gear Box
5. U Joint
6. Propeller Shaft
7. Differential
8. Front and Rear Axles
9.Steeing System
10. Braking and lighting system

11. FUNCTIONS OF THE CHASSIS FRAME:
1. To carry load of the passengers or goods carried
in the body.
2. To support the load of the body, engine, gear box
etc.,
3. To withstand the forces caused due to the
sudden braking or acceleration
4. To withstand the stresses caused due to the bad
road condition.
5. To withstand centrifugal force while cornering

12. TYPES OF CHASSIS FRAMES:
There are three types of frames
1. Conventional frame
2. Integral frame
3. Semi-integral frame
1. Conventional frame: It has two long side members
and 5 to 6 cross
members joined together with the help of rivets and
bolts. The frame sections
are used generally.
a. Channel Section - Good resistance to bending
b. Tabular Section - Good resistance to Torsion
c. Box Section - Good resistance to both bending and
Torsion

13. 2. Integral Frame: This frame is used now a days in most of the
cars. There is no frame and all the assembly units are attached
to the body.
All the functions of the frame carried out by the body itself.
Due to elimination of long frame it is cheaper and due to less
weight most economical also.
Only disadvantage is repairing is difficult.
3. Semi - Integral Frame: In some vehicles half frame is fixed in
the front end on which engine gear box and front suspension is
mounted.
It has the advantage when the vehicle is met with accident the
front frame can be taken easily to replace the damaged chassis
frame.
This type of frame is used in FIAT cars and some of the European
and American cars.

14. VARIOUS LOADS ACTING ON THE FRAME:
Various loads acting on the frame are
1. Short duration Load - While crossing a
broken patch.
2. Momentary duration Load - While taking a
curve.
3. Impact Loads - Due to the collision of the
vehicle.
4. Inertia Load - While applying brakes.
5. Static Loads - Loads due to chassis parts.
6. Over Loads - Beyond Design capacity.

15. The Automobile bodies are divided in three groups
According to Chassis design the body can divided
into
1. Conventional Type
2. Integral Type
3. Semi- Integral Type
According to other usage:
1. Light vehicle Bodies - cars, jeeps
2. Heavy vehicle Bodies – Busses, Lorries
3. Medium vehicle Bodies - Vans, Metadoors

16. REQUIREMENTS OF BODIES FOR VARIOUS TYPES OF
VECHILE:
The body of the most vehicle should fulfill the following requirements:
1. The body should be light.
2. It should have minimum number of components.
3. It should provide sufficient space for passengers and
luggage.
4. It should withstand vibrations while in motion.
5. It should offer minimum resistance to air.
6. It should be cheap and easy in manufacturing.
7. It should be attractive in shape and colour.
8. It should have uniformly distributed load.
9. It should have long fatigue life
10.It should provide good vision and ventilation.

19. 19
Automobile Bodies
• Most made of
stamped steel parts
• A few cars made of
aluminum (NSX
Cadillac Allenta)
• Some use composite
materials (Saturn or
GM Minivan)

20. 20
Chassis or Frame
• Under lying structure
of all vehicles
• Three types of frame:
• 1 – Full frame
• 2 – Unitized frame
called unibody
• 3 – Space frame

21. 21
Full Frame Chassis
• Uses welded steel alloy
metal
• C-channel or box frame
construction
• Note engine cradle in
front and rear axle hump
in rear
• Used on large cars and
most all trucks
• Body made in separate
unit and bolted to chassis

22. 22
Unitized Body Construction
• Called Unibody
• All body and frame
parts welded
together
• Light weight but
strong structurally
• Most cars use this
construction

23. 23
Space Frame Construction
• Newest type of
construction
• Hybrid unibody
• Used on race cars first
but now used in
passenger cars
• Many use plastic
fenders and body
panels

24. 24
Chassis Related Systems
• Braking
system
• Suspension
system
• Steering
system

25. Automobile Body Parts

27. Basic Engine
Parts
The core of the engine is the cylinder, with the
piston moving up and down inside the cylinder.
Most cars have more than one cylinder (four, six and
eight cylinders are common).
In a multi-cylinder engine, the cylinders usually are
arranged in one of three ways:
inline, V or flat (also known as horizontally opposed or
boxer), as shown in the following figures.
1) Inline - The cylinders are arranged in a line in a
single bank.

28. V - The cylinders are arranged in
two banks set at an angle to one
another.
Flat - The cylinders are arranged in
two banks on opposite sides of
the engine

40. Basically the cylinder liner is a cylindrical
shell which acts as the enclosure in which
the combustion takes place.
The cylinder liner forms the cylindrical
space in which the piston reciprocates.
It is under the fluid pressure due to
combustion and hence must withstand
the high level of hoop stress induced in it.
Cylinder liner

41. A cylinder liner is a removable component,
cylindrical in shape, inserted into the engine
block. It provides the surface for the piston to
slide and carry out its compression task. It can
be replaced when worn out.
Cylinder liners are made from close grained
cast iron.
In four stroke cycle engines they are simple
cylindrical shapes flanged at the top end to
provide location and secure them in the
cylinder blocks or to the water jacket.

44. Cylinder block is made from grey cast iron, the
cylinder liner is manufactured from cast iron
alloyed with chromium, vanadium and
molybdenum.
Cast iron contains graphite, which assists
lubrication, whereas the alloying elements help
resists corrosion as well as improve wear
resistance at higher temperature.
In wet liners the water is in direct contact with
outer surface of the liner whereas in dry liners the
water is in indirect contact with outer surface of
the liner, i.e. cylinder casting contains wet jackets.

47. Cylinder Block

48. A cylinder block is a unit comprising several cylinders
(including their cylinder walls, coolant passages,
cylinder sleeves if any, and so forth).
The metal casting in which the cylinders of an internal-
combustion engine are bored.
The metal casting containing the cylinders and cooling
channels or fins of a reciprocating internal-combustion
engine.
What Is the Function of Cylinder Head?
The function of a cylinder head is to coordinate
airflow in and out of the engine. The cylinder head
also acts as a housing for the valve-train and focuses
the combustion pressure on the piston head.

52. Piston
A piston is a cylindrical piece of metal in the form of a
inverted bucket that moves up and down inside the cylinder.
Pistons are constructed of aluminium alloy.
Parts include top, ring grooves, ring lands, skirt and piston
pin boss. Cooling fins on the bottom help the oil carry heat
away from the piston top.

57. A piston of an Internal combustion engine serves the
following functions:
1.The piston receives the thrust produced by combustion
and transmits the power to the connecting rod.
2.It reciprocated to cause different strokes
3.It acts as a bearing to the small end of connecting rod
4. It forms a movable wall of the combustion chamber
5. It transmits turning force to the crankshaft via the
connecting rod
6.It functions like a crosshead and transmits side thrust
,which is due to the angularity of the connecting rods, to
the cylinder walls

58. 4. The piston operation must not be noisy
5. The piston must have less coefficient of expansion
3. The piston must be a good conductor of heat so that
detonation is suppressed and higher compression
ratio is possible to get fuel economy.
The piston must possess the following qualities:
1. It must be strong enough to withstand high pressure
caused due to combustion of fuel
2. It must be light in weight to have minimum primary
and secondary forces, which are caused due to the
inertia forces of the reciprocating masses.

60. A piston pin, also known as a wrist pin, is a hardened
steel pin which connects an engine's piston to a
connecting rod. The piston pin is hollow to reduce
weight and is held in place with a number of different
methods.
Piston pins are made of hardened steel, many high-
performance applications utilize tool steel pins.
These tool steel pins are the strongest and most
durable, can withstand ultra high horsepower.
Piston: aluminum alloy; cast or forged
Connecting rod: low carbon, high strength steel;
forged, powder metallurgy
Piston pin: low carbon, high strength steel;

65. A connecting rod is an engine component that transfers motion from
the piston to the crankshaft and functions as a lever arm.
Connecting rods are commonly made from cast aluminum alloy and
are designed to withstand dynamic stresses from combustion and
piston movement.
The small end of the connecting rod connects to the piston with a
piston pin.
The piston pin, or wrist pin, provides a pivot point between the piston
and connecting rod.
Spring clips, or piston pin locks, are used to hold the piston pin in
place.

66. The big end of the connecting rod connects to the
crankpin journal to provide a pivot point on the
crankshaft.
Connecting rods are produces as one piece or two-
piece components.
A rod cap is the removable section of a two-piece
connecting rod that provides a bearing surface for the
crankpin journal.
The rod cap is attached to the connecting rod with
two cap screws for installation and removal from the
crankshaft.

67. Types includes
•Plain rod.
•Fork and Blade rod.
•Master and Articulated.
Plain type rods
Plain type rods used on inline
and opposed engines. Small
bushing at piston pin end is
pressed in place and reamed
to final dimensions.
Large end of rod includes a
cap , bolts , nuts and plain
bearing inserts. Rods are
numbered as to cylinder and
for cap-to-rod alignment.

68. Fork and blade connecting rod.
Fork and blade connecting rods are used on "V"
type engines.
One rod inside another allows cylinders to be
aligned and to share a common location on the
crankshaft.

69. Master and Articulating rod.
Master and Articulating rods are used on radial engines
Uses "Knuckle pins" to retain articulated rods to
master.

70. The crankshaft, sometimes abbreviated as crank, is the part of
an engine that translates reciprocating linear piston motion into
rotation.
To convert the reciprocating motion into rotation, the crankshaft
has "crank throws" or "crankpins", additional bearing surfaces
whose axis is offset from that of the crank, to which the "big ends"
of the connecting rods from each cylinder attach.
It is typically connected to a flywheel to reduce the pulsation
characteristic of the four-stroke cycle, and sometimes a torsional
or vibrational damper at the opposite end, to reduce the torsional
vibrations often caused along the length of the crankshaft by the
cylinders farthest from the output end acting on the torsional
elasticity of the metal.

72. Crankshaft Materials
• Cast iron
• Cast steel
• Forged steel
• Nodular iron
• Malleable iron
• Billet steel
• Titanium

73. Surface Treatments
• Surface treatments are used to improve wear
characteristics of crankshaft journals
• Surface treatments only affect a shallow area
and if the crank is ground it must be re-treated
to retain the same surface hardness