This document provides information about automobile engineering. It begins with definitions of an automobile and discusses the first automobiles invented by Cugnot and Karl Benz. The core components of an automobile are then outlined, including the basic structure, engine, transmission system, auxiliaries, controls, and superstructure. Details are given about engine components like the cylinder block, piston, connecting rod, and crankshaft. Different types of valves and valve actuation mechanisms are also summarized. Finally, the document discusses classifications of automobiles based on various factors.

1. AUTOMOBILE ENGINEERING
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REGENT EDUCATION & RESEARCH
FOUNDATION,GROUP OF INSTITUTION
PRESENTED BY: MD SHOHRAB ALAM
ROLL NO: 26300719002
DEPARTMENT: MECHANICAL ENGINEERING
YEAR:2019-2023
SEMESTER: 7TH SEMESTER
TOPIC NAME: AUTOMOBILE ENGINEERING

2. What is an ‘Automobile’??
• A vehicle producing power within itself for its propulsion is known
as a Self propelled vehicle.
• Eg. Moped, Scooter, motorcycle, Car, jeep, truck, tractor, ships,
aircrafts, rocket etc.
• A self propelled vehicle used for transportation of goods &
passengers on the ground is called an Automobile.
• Different from Aeronautical vehicles (planes, helicopters, rockets) &
marine vehicles (ships, boats, submarines)
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3. First Automobile
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Cugnot Steam Trolley, Steam Engine powered, 1768

4. Karl Benz
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Inventor of the first gasoline powered automobile, 1886

5. Benz Patent Motorwagen – 1886 – first production car powered
by an IC Engine – 954 cc, 2/3 hp or 0.5 kW at 250 rpm
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6. COMPONENTS OF AN AUTOMOBILE
1. The Basic structure
2. The Engine
3. The Transmission system
4. The Auxiliaries
5. The Controls
6. The Superstructure
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7. COMPONENTS OF AN AUTOMOBILE
1. The Basic Structure:
It consists of the frame, the suspension system, axles, wheels
and tyres.
2. The Engine:
It provides the motive power for all various functions which
the vehicle or any part of it, may be required to perform. The
engine for automotive use is IC type.
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8. 30 August 2022 8
ENGINE

9. COMPONENTS OF AN AUTOMOBILE
3. The Transmission System:
It consists of a Clutch, a gear box giving four, five or even
more different ratios of torque output to torque input, a
propeller shaft to transmit the torque output from the gear box
to the rear axle and a differential gear to distribute the final
torque equally between the driving wheels.
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10. Transmission System
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11. COMPONENTS OF AN AUTOMOBILE
4. The Auxiliaries:
The Electrical systems.
5. The Controls:
They consists of steering systems and brakes
6. The Super Structure:
In those cases where frameless construction is not
adopted there must be super structure i.e, the body.
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12. Engine Systems
1. Cooling System
2. Fuel System
3. Lubrication System
4. Ignition System
5. Electrical System
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13. Basic Engine Terminology
1. Bore: The inside diameter of the cylinder is called bore
2. Stroke: The linear distance along the cylinder axis between two
limiting position s is called stroke.
3. Top Dead Center ( T.D.C.) : The top most position of the piston
towards cover end side of the cylinder is called T.D.C.
4. Bottom dead Center ( B.D.C.) : The lowest position of the piston
towards the crank end side of the cylinder is called B.D.C.
5. Clearance Volume : The volume contained in the cylinder above
the top of the piston , when the piston is at top dead center , is
called the clearance volume.
6. Swept Volume: The volume swept through by the piston in moving
between T.D.C. and B.D.C, is called swept volume or piston
displacement.

14. Basic Engine Terminology
7. Compression Ratio: It is the ratio of Total cylinder
volume to clearance volume
Comp. Ratio
6:1 to 10:1 for Petrol engines
15:1 to 25:1 for Diesel engines
Comp. Temp.
250*C for S.I.
600*C for C.I.
Comp. Pressure
1 MPa for S.I.
3.5 MPa for C.I.

15. Classification Of Automobiles
1. Based on Purpose
1. Passenger Vehicles – Car, Bus, Motorcycle
2. Goods Vehicles – Lorry, truck, Pick up
2. Based on Capacity
1. Heavy Motor Vehicle (HMV) – large trucks, Buses, Tractor
2. Light Motor Vehicle (LMV) – Cars, Jeep, Motor cycles
3. Medium Vehicle – Small trucks, Minibus, Tempo
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16. Classification Of Automobiles
3. Based on Fuel Source
1. Petrol Engine 2. Diesel Engine
3. Gas Vehicles 4. Solar Vehicles
5. Hydrogen Vehicles 6. Electric Vehicles
7. Steam Engine vehicles
8. Hybrid Vehicles
9. Hybrid Electric Vehicles
4. Based on Type of Transmission
1. Automatic transmission vehicles – mostly American
2. Conventional transmission vehicles – Most Indian Vehicles
3. Semi - Automatic transmission vehicles – mostly British
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17. Classification Of Automobiles
5. Based on Make
1. MARUTI SUZUKI 2. HINDUSTAN MOTORS
3. TATA MOTORS 4. MAHINDRA & MAHINDRA
5. TVS MOTORS 6. HERO MOTOCORP
7. ASHOK LEYLAND8. EICHER MOTORS
9. FORCE MOTORS 10. BAJAJ AUTO LTD
11. ROYAL ENFIELD
12.VOLVO, VOLKSWAGEN, MERC BENZ, BMW,
CATERPILLAR, BENTLEY, AUDI etc.
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18. Classification Of Automobiles
6. With respect to the drive
1. Left Hand Drive 2. Right Hand Drive
3. Fluid Drive 4. Front Wheel Drive
5. Rear Wheel Drive 6. All Wheel Drive (AWD or 4WD)
7. With respect to the Suspension
1. Conventional – Leaf Spring
2. Independent – Coil, Torsion bar, MacPherson Strut
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19. Classification Of Automobiles
8. With respect to the Type of Engine
1. Reciprocating – Piston Engines
2. Rotary – Wankel Engine, Gas turbine
9. With respect to the body & doors
1. Sedan
2. Hatchback
3. Station Wagon
4. Convertible
5. Sports utility vehicle
6. Multi Utility Vehicle (MUV or MPV)
7. Delivery Vans etc
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20. Classification Of Automobiles
10. Based on no. of wheels
1. Two wheeler
2. Three wheeler
3. Four
4. Six
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21. The Transmission system
General layout of transmission system of an automobile
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22. Functions of transmission system
1. To disconnect the engine from the road wheels when required.
2. To connect the engine to the driving wheels without shock
3. To vary the leverage between the engine and driving wheels.
4. To reduce the engine speed permanently in a fixed ratio
5. To turn the drive through a right angle.
6. To make provision such that the driving wheels may rotate at
different speeds while taking turns.
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23. Various components of transmission
system
1) Engine
2) Clutch
3) Gearbox
4) Universal joints
5) Differential
6) Wheels
7) Front and rear axles
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24. .
 Clutch : Its purpose is to enable the driver to disconnect the
drive from the road wheels instantaneously and to engage
drive from the engine to the road wheels gradually while
moving the vehicle from rest.
 Gearbox : The gear box or the transmission provides the
necessary leverage variation between the engine and road
wheels.
 Differential : While taking turns, the driving wheels must at
different speeds. This is done with the help of differential.
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25. Engines
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27. Engine & Engine components
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28. 30 August 2022 28

29. Engine & Engine components
1. Cylinder Block 2. Cylinder head
3. Crankcase 4. piston
5. Piston rings 6. Piston pin
7. Connecting rod 8. Crank shaft
9. Flywheel
10. Valves and valves mechanism
11. Rocker arm 12. Camshaft
13. Accessories: Air cleaner, oil filter, automatic chokes,
automatic heat controls.
other parts: Spark plug, ignition devices, carburetor
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30. Engine components
1. Cylinder block
It consists of three parts.
 The cylinder in which the pistons slide up and down.
 The passages for the flow of cooling water.
 The bottom of the block supports the crankshaft, oil sump and
camshaft.
• Various engine accessories & clutch housing are bolted to it.
The Cylinder block is usually made from grey cast iron.
Sometimes its made with addition of nickel or chromium, Aluminium
and Compacted Graphite Iron(CGI) – heavy duty alloy.
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31. Engine components : 1.Cylinder block
Cylinder block and crankcase form a single casting
(monoblock). It gives a rigid structure and extra strength.
The Cylinder block may also have a separate crankcase
for the crankshaft.(Individual block)
Advantages of Monoblock
No water leakage, more rigid
Size is reduced, easy water circulation
Advantages of Individual block
Easy for repairing, less replacement cost
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32. Cylinder Block (Monoblock)
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33. 2. Cylinder Head
 The top of the cylinder is covered by a separate cast piece known as
the cylinder head. It is bolted to the cylinder block.
 It is usually made of grey iron or Aluminium alloy. Aluminium has
the advantage of light in weight and high heat conductivity.
 A flat piece of gasket is placed is placed between the cylinder head
and block to retain compression in the cylinder and to provide a gas
and water tight seal.
 Gasket made of Copper-asbestos-Copper.
• Camshafts, rockers & valves may be carried on the cylinder head.
• Water passages may also be provided to cool the valves, the head
and the spark plugs.
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34. 30 August 2022 34

35. 3.Piston
Piston helps to convert the chemical energy obtained by
the combustion of fuel into useful mechanical power.
The purpose of the piston is to provide a means of
conveying the expansion of the gases to the crankshaft through
the connecting rod.
It is provided with piston rings to provide a good seal
between the cylinder wall and piston. It has to withstand very
high temperatures of combustion.
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36. 36

37. Piston
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Materials Used
Aluminium alloys, Cast steel,
Cast Iron or Chrome Nickel

38. Engine components : Piston
Head or Crown: top of the piston
Ring grooves
Skirt: parts below the ring grooves
Lands: the portion that separates the grooves.
The piston must posses the following qualities
 Rigidity to withstand high pressure.
 Lightness to reduce weight and inertial forces.
 Good heat conductivity to reduce the risk of detonation
 Silence in operation
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39. 4.Piston rings
Fine grained alloy cast iron used for the piston rings.
 Cast Iron plated with Chromium, Cadmium or Tin.
Functions:
 Prevent the escape of burnt gases from the combustion
chamber past the piston (Crank case blow by).
 Prevent the leakage of oil into the combustion space.
 Heat from the piston is transmitted to the cylinder via piston
rings.
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40. Piston Rings
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41. 4.Piston rings
a. Compression rings:
o Prevents the blow by or escape of burnt gases to the crank case.
o 2 or 3 compression rings are fitted into the top grooves.
o A gap is formed in the ring to impart the property of radial
expansion and compression.
o This gap is necessary for assembly and renewal of ring
o Made from Cast Iron plated with Chromium, Cadmium and Tin.
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42. 4.Piston rings
b. Oil Control rings:
o These rings scrap off excessive oil from the cylinder wall and
return it to the oil sump.
o The oil control ring is fitted into the lower groove of the
piston.
o Oil control grooves has a series of slots. These slots transfer
the excess oil through the holes in the piston groove to the
inside of the piston and to the sump
o Made from steel, outer edges of the rings chromium plated
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43. 43

44. 5.Connecting rod
 The connecting rod usually has I-beam cross-section.
 Small end is connected to the piston pin and big end to the crank
pin
 The function of the connecting rod is to convert linear motion of the
piston into rotary motion of the crankshaft.
 The connecting rod carries the power thrust from piston to the
crank pin. So it must be strong, rigid and as light as possible.
 Always made from steel forgings, in few cases Aluminium alloy is
used.
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45. 5. Connecting rod
• Cross section is an “H” or “I”
• Types include :
a) Plain Rod
b) Fork and blade rod
c) Master and articulated
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46. a) Plain Rod
o Used on inline and opposed engines
o Small bushing at piston pin end is pressed in place and reamed to
final dimensions
o Large end of rod includes a cap, bolts, nuts, and plain bearing
inserts
o Rods are numbered as to cylinder and for cap-to-rod alignment
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47. b) Fork and Blade Connecting Rod
• Used on “V” type engines
• One rod inside another allows cylinders to be aligned and to
share a common location on the crankshaft
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48. Fork and Blade Type C Rod
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49. c) Master and Articulating Rod
o Used on radial engines
o Uses “knuckle pins” to retain articulated rods to master
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50. 6. Crank shaft
 It is the 1st part in the power transmission.
 The reciprocating motion of the piston is converted into rotary
motion of the crankshaft with the help of connecting rod.
 It consists of crankpins, webs, balancing weights and main
journals.
 Big end of connecting rod is connected to the crankpin of the
crankshaft.
 The crank shaft is supported by the main bearings on the
main journals.
 Made of Casting or forging of heat treated alloy steel.
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51. Crankshaft
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52. Engine components : 6.Crank shaft
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53. Valve Actuating Mechanisms
 To admit the air-fuel mixture in the engine cylinder and to force the
exhaust gases out at correct timings, some control system is
necessary, which is provided by the valves.
 The engine valves may be broadly divided into 3 main categories:
1. Poppet valve
2. Sleeve valve
3. Rotary valve
A most common type of valve used at present is poppet valve.
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54. Valves
• Usually made of Austenitic Stainless Steel which is a corrosion &
heat resisting material.
• Race engines use Beryllium-Copper alloy seats with Titanium
valves (21-4N) – 40% lighter than Steel.
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55. 55

56. Poppet Valve
• The valves are operated by cams mounted on a camshaft.
• According to the location of the valves,
the valve mechanisms are
a. Straight poppet valve mechanism
b. Overhead poppet valve mechanism
c. Overhead camshaft mechanism
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57. .
• The valve mechanism to operate
the valve when it is in the
engine block(as in L,T and F-
head).
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a. Straight (or side) poppet valve
mechanism

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59. b. Overhead poppet valve mechanism
• The valve mechanism to operate the
valve when it is in the cylinder head( as in
I and F head design).
• It requires two additional moving parts-
the push rod and the rocker arm. As the
cam rotates, it lifts the valve tappet.
• It actuates the push rod and thereby the
rocker arm end pushes the valve stem to
open the valve.
c
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60. Overhead Poppet Valve Mechanism
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61. 61

62. c. Overhead camshaft mechanism
• In this type, the camshaft is
mounted above the valve in the
cylinder head.
• The cam on the cam shaft operates
the valve directly. A small clearance
is provided in between the cam and
valve cap.
• The clearance is adjusted by
providing small shims in the bottom
of the cap.
c
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63. 63

64. SOHC & DOHC
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65. 65

66. Variable Valve Timing (VVT)
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67. Variable Valve Timing (VVT)
• Variable Valve Timing (VVT) is the process of
altering the timing of a valve lift event, and is
often used to improve performance, fuel
economy or emissions. It is increasingly being
used in combination with variable valve
lift systems.
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68. • 1. Phase changing systems: With a single
camshaft, all the valve events for both intake
and exhaust valves are shifted by the same
amount, whereas if separate camshafts are
used for intake and exhaust valves, such a
phase changing system can change the valves
events can be changed independently for the
intake and the exhaust valves.
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69. 2. Profile switching systems: these can change
independently the valve-event timing and the
valve lift. There are two camshafts with separate
cam profiles. The system enables the valve
operation to be switched between these
camshafts at a particular engine speed.
- High power output
- Low emission level
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70. 3. Variable event-timing systems: can change
both the phase and duration of valve events and
can be optimized for different engines speed
and load conditions due to which it is obtain:
I. Increase in full-load torque.
II. Reduction in part-load emissions.
III. Fuel economy e.g. decrease of exhaust
emissions.
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71. 4. Variable lift systems: the main adv. Of such
systems is reducing the pumping losses due to
convectional throttle.
5. Electronic valve actuation systems: due to
their precise control, these have the maximum
potential for optimizing the valve events.
Besides, all the valve events including the lift csn
be directly controlled.
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72. Automobile Chassis
• Chassis – French term used to denote the main structure of a vehicle
• It’s the backbone of the vehicle – made of steel.
• All moving parts are fitted to it.
• To give it extra strength it is provided with bolted, riveted or welded
cross pieces.
• All major units required to propel the vehicle, direct its motion,
stop it as well as permit to run smoothly over varying road surface
is known as chassis.
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73. Automobile Chassis
• The power unit is connected with the transmission.
• The structural frame fitted to the axles through the suspension
system carries the power train.
• For an automobile to propel safely on the road, the engine, the
transmission system, suspension, steering & brakes are included to
the basic frame. These units combined together – Chassis.
• The body or Cabin is jointed to the cabin by means of bolts & nuts
or by welding.
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74. 74

75. Chassis Components
• Frame
• Front Suspension
• Steering Mechanism
• Wheels, Tyres and axles – rear & front springs & shock absorbers
• Engine, Clutch & Gearbox
• Propeller shaft
• Radiator
• Differential, half shaft & universal joint
• Brakes & Braking system
• Fuel tanks, pipes & connecting fuel lines.
• Battery & electrical system
• Silencer
• Car Body
• Car Body accessories like lights, radio, wiper, mirrors etc.
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76. Desired qualities of a Chassis
• Fast pick up
• Strength & Safety
• Durability
• Dependability
• Ease of control
• Quietness
• Speed
• Power accessibility
• Low centre of gravity
• Simplicity of lubrication
• Economy of operation.
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