This document provides an overview of farm machinery engine systems. It discusses the classification and components of internal combustion engines, including differences between two-stroke and four-stroke engines. The fuel, lubrication, ignition, cooling and governor systems are also mentioned. Tractor systems such as power transmission, steering, brakes and hydraulics are briefly covered. The summary discusses the key components and cycles of petrol and diesel engines in 2-3 sentences.

1. Farm Machinery and Power
Engine systems

2. Out line
 Introduction
 Classification of I.C. Engine
 Four stroke and two stroke Engine
 I.C. Engine terminology ,
 Difference between petrol engine and diesel engine ,
Two stroke cycle engines ,
 Difference between two stroke and four stroke cycle engines

3.  Fuel System
 Lubrication System
 Ignition System
 Cooling System
 Governor
Engine system
 Engine system
 Power transmission system
 Steering system
 Brake system
 Noise and vibration control
 Hydraulic system
Tractor system

4. Introduction
Heat engine is a mechanical device or machine which converts the
heat energy to mechanical work.
Or
Heat engine is an equipment which generate thermal energy and
transforms it into mechanical energy.
Mechanical
work
Heat
Energy
Engine

5. Internal Combustion Engine
the working fluid consists of a combustible fluid placed inside a
cylinder these engines, the fluid undergoes combustion inside the
cylinder and expands.
External Combustion Engine
The combustion takes place outside the cylinder. Heat then needs to
be transferred to the cylinder where work is done. Steam engines
are an example of external combustion engines.

6. Classification of Engine
2- stroke
4 -stroke
1. Air cooled
2. Water cooled
1.Spark ignition
2. Compression
ignition
Internal combustion IC – Engine
External combustion EC - Engine

7. I. C. ENG INES E. C. ENGINES
 Fuel combustion take
place inside the cylinder.
 Fuel combustion take place
outside the cylinder.
 Compact in size and more
efficient.
 Larger in size and less
efficient.
 Low initial cost.  More initial cost.
 Working fluid is mixture
of air and fuel.
 Working fluid is steam.
 Easier and quick starting
of these engines.
 Starting is difficult and more
time is required.
 Costly fuels are required
like petrol and diesel.
 Cheaper fuel may be used like
coal.
 More suitable for mobile
applications.
 Less suitable for mobile
applications.

8.  Cylinder
 Piston
 Piston rings
 Connecting rod
 Crank and
crankshaft
 Valves
 Flywheel
 Crankcase
 Camshaft
 Timing gear
Engine Component

9. Cylinder
 Part of the engine
where fuel is burnt
and power is
developed.
 Inside diameter is
called as bore.
 Sleeve is fitted tightly
in the cylinder to
prevent wearing of
block.

10. Close fitting hollow –
cylinder plunger moving
to and fro in the
cylinder.
Function – power
developed by the
combustion of fuel is
transmitted by piston to
the crank-shaft through
the connecting rod.
Piston

11. Piston Rings
Metallic rings inserted
into groves provided
at top end of the
piston.
Function – it maintains
a gas-tight joint
between the piston
and the cylinder.
Piston Rings are of two type
1. Compression Ring
2. Oil Ring

12. Connecting Rod
Link that connects the
piston and crankshaft by
means of pin joint.
Function – A connecting
rod, also called a con rod,
is the part of a piston
engine which connects the
piston to the crankshaft.
Together with the crank,
the connecting rod
converts the reciprocating
motion of the piston into
the rotation of
the crankshaft

13. Crankshaft
The crankshaft is a moving part of the internal combustion
engine (ICE). It's main function is to transform the linear motion of
the piston into rotational motion. The pistons are connected to
the crankshaft through the connecting rods. The crankshaft is
mounted within the engine block.
Camshaft
A camshaft is a rotating object— usually made of metal— that
contains pointed cams, which converts rotational motion to
reciprocal motion. Camshafts are used in internal combustion
engines (to operate the intake and exhaust valves), mechanically
controlled ignition systems and early electric motor speed
controllers.
Valves
These are devices which control the flow of intake and exhaust
gases.

14. Fly wheel
Flywheel, heavy wheel attached to a rotating shaft so as to smooth
out delivery of power from a motor to a machine. The inertia of
the flywheel opposes and moderates fluctuations in the speed of
the engine and stores the excess energy for intermittent use.
Mounted on crankshaft to maintain uniform rotation of crankshaft.
Crankcase
Enclosure for crankshaft and sump for lubricating oil.

17. In four stroke Petrol engine the vale operating for inlet is called inlet valve and the
valve operating for exhaust is called Exhaust valve. In Petrol engine SPARK plug
fitted at the top of cylinder head initiates the ignition of the air fuel mixture.
The piston performs four strokes to complete one working cycle.
The four different strokes are ; (1) SUCTION STROKE (2) COMPRESSION
STROKE (3) POWER STROKE (4) EXHAUST STROKE.
Otto cycle engine

18. Four stroke Petrol Engine

19. Pistons Position Du rin g The Four Stroke
Cycle

20. 
The four stroke Diesel engine is also consists of SUCTION,
COMPRESSION,POWER and EXHAUST strokes.
The basic construction of a four stroke diesel engine is same as that of four
stroke petrol engine, except instead of spark plug, a fuel injector is mounted in
its place .

21. Fo u r Stroke Diesel E n g i n e

22.  Suction stroke
 Compression stroke
 Power stroke
 Exhaust stroke
Four stroke petrol engine

23. SUCTION STROKE
Inlet is open exhaust is
closed.
Piston moves from
TDC to BDC.
Crankshaft revolves
half the rotation.
Cranking
Petrol air mixture
drawn into cylinder due
to pressure difference.

24. COMPRESSION STROKE
Both inlet and exhaust are
closed.
Piston moves from BDC to
TDC.
Crankshaft revolves half the
rotation.
Cranking
Petrol air mixture is
compressed to a ratio of
1:11.
This mixture is ignited by
spark plug.

25. POWER STROKE
Piston moves from TDC to
BDC.
Crankshaft revolves half the
rotation.
 burnt gases generate energy
and force the piston to move
down.

26. EXHAUST STROKE
exhaust is open and inlet
is closed.
Piston moves from BDC
to TDC.
crankshaft revolves half
the rotation.
energy for this stroke is
supplied by flywheel.
Burnt gases are expelled
out through outlet port.

27. Four Stroke Petrol Engine

28. Four Stroke Diesel Engine

29.  Inlet is open exhaust is
closed.
 Piston moves from TDC to
BDC and crankshaft
revolves half the
revolution.
 Cranking during first
cycle.
 Due to the pressure
difference air enters the
cylinder through air filter.
Suction stroke

30.  Inlet and exhaust are
closed.
 Piston moves from BDC to
TDC.
 Cranking required in first
cycle.
 Air will be compressed to
a ratio of 1:20.
 Diesel oil is sprayed into
cylinder by injector and
auto-ignition takes place.
Compression stroke

31.  Piston moves from TDC
to BDC.
 Inlet and exhaust valves
are closed.
 burnt gases generate
energy and force the
piston to move down till
injection of fuel is
complete.
Power stroke

32.  Exhaust is open and inlet is
closed.
 Piston moves from BDC to
TDC.
 Crankshaft revolves half the
rotation.
 Energy for this stroke is
supplied by flywheel.
 Burnt gases are expelled out
through outlet port.
Exhaust stroke

33. Four Stroke Diesel Engine

35. PETROL ENGINE DIESEL ENGINE
 Works on Otto cycle .  Works on Diesel Cycle .
 Petrol is used as fuel .  Diesel is used as fuel .
 Air and fuel mixture enters in cylinder
during suction stroke .
 Only Air is drawn during the suction
stroke
 Low compression ratio ranging from 4:1
to 8:1 .
 High compression ratio ranging from14:1
to 22:1 .
 The compressed charge is ignited by the
spark plug.
 The fuel injector is used in Diesel engine.
 High engine speed of about 3000 RPM .  Low to medium engine speed ranging
from 500 to 1500 RPM.
 The Thermal efficiency is 25-32 % and
is lower due to lower Compression ratio .
 The Thermal efficiency is 32-38 % and is
higher due to high Compression ratio .
 Lighter in weight because maximum
pressure and Temperature is less .
 Heavier in Weight because maximum
pressure and temperature is high .
 Less Costlier .  More Costlier .
 Maintanence cost is Less .  Maintanence cost is Slightly higher .
 Easier starting even in cold weather .  Difficult to start in cold weather .
 Running cost Higher because petrol is
Costlier .
 Running cost is Less because diesel is
Cheaper .

38. Two stroke Engine Four stroke Engine

39. STROKE
ENGINE TWO STROKE ENGINE
• Fourpistonstrokesrequiretocompleteonecycle .
• Twocompleterevolutionsofcrankshaftisrequiredto
completeone cycle.
• Equaltohalfofthespeedofenginecrankshaft. Number
ofpower stroke/min. n=N/2
• Powerisdevelopedineveryalternaterevolutionof crank
shaft.
• Thepowerisdevelopedineveryalternaterevolution,
henceheavy flywheelisrequired.
• TheseenginesareHeavier,largerandrequiredmore
space.
• Theinletandexhaustvalvearerequireandtheyare
operatedby valveoperatedbyvalveoperating
mechanism.
• Lubricatingoilconsumptionisless .
• Thermalefficiencyishigher.
• MechanicalefficiencyisLowbecauseofmorenumber
ofmoving parts.
• TheseEnginesareusedbasicallyinHighPower
ApplicationWhere more spaceisavailablelikeCars,
Truck,Tractors , Busesetc.
• Onlytwopistonstrokesrequiredtocompleteonecycle .
• Onlyonecompleterevolutionofcrankshaftisrequiredto
complete onecycle .
• Equaltothespeedofenginecrankshaft. Numberof
power stroke/min. n=N
• Powerisalsodevelopedineveryrevolutionofcrankshaft
hencefor samecylinder.
• Thepowerisdevelopedineveryrevolution, hencelighter
flywheel isrequired .
• Theseenginearelightermorecompactandrequireless
space.
• Inplaceofvalve,portsareusedwhichopensandcloseby
motion ofpiston itself.
• Lubricatingoilconsumptionismorebecauselubricatingoil
ismixed withfuel
• LessThermalefficiency.
• MechanicalefficiencyisHighbecauseoflessnumberof
moving parts.
• TheseEnginesareusedbasicallyinLowPowerApplication
Where lessspaceisavailablelikeMopeds,Scooters,Motor
cycleetc.
FOUR STROKE ENGINE

40. I.P.
B.P.
mech 
I.P.
mf  C.V
it 
B.P.
mf  C.V
bt 
a ir
it
re l 


41. 1
(r)
air  1




1 
1
 (1)
 1
 
 1
(r)
air 1
mf
kg /kWh
B.P.
SFC 

42.  Fuel : It is a substance consumed by
the engine to produce energy
 Eg. Petrol, Diesel, kerosene etc.
Fuel system
s.
no.
Name of the fuel API degree Specific
Gravity
Calorific value
(Kcal/kg)
1. Light diesel oil (LDO) 22 0.920 10300
2. High speed diesel
(HSD)
31 0.820 10550
3. Power Kerosene 40 0.827 10850
4. Petrol 63 0.730 11100
Important properties of oil

43. Quality of the fuel
 Volatility
 Calorific value of fuel
 Ignition quality
Cetane number (Diesel fuel)
Ocatne number ( Petrol fuel)
Fuel test
 Gravity test (API degree)
 Distillation test
 Vapour pressure test
 Sulphur content
 Carbon residue test
 Colour test
 Gum test

44. Type of fuel system
Spark Ignition
Mixture of air and fuel
compressed and ignited by
spark
Compression Ignition
Air alone is compressed
and fuel is injected at the
end of compression stroke

45. Fuel system of spark ignition engine (petrol engine)
1. Fuel tank
2. Sediment bowl
3. Fuel filters
4. Fuel lift pump
5. Carburettor
6. Spark plug
7. Inlet manifold

46. Working of the spark ignition system

47. Carburettor

48. Fuel tank
Fuel Filters
Fuel Filter

49. Fuel supply system of diesel engine
 Fuel tank
 Fuel lift pump
 Fuel filters
 Fuel injection
pump
 High pressure
pipeline
 Overflow valve
 Fuel injectors
Fig. Flow diagram Of fuel system in diesel engine

50. Working of Fuel system of diesel engine

52. Fuel injection pump