All types of lubricating and cooling system which are used in I.C. engine are discussed over here.

1. LUBRICATING AND
COOLING SYSTEM

2. LUBRICATING SYSTEM
• Lubrication is a process of reducing friction and
WEAR between the surface of two parts which are
moving relative to each other by interposing a
substance called a LUBRICANT in between them.
It is divided as follows,
 (1) petroil system (4) wet sump system
 (2) splash system (5) dry sump system
 (3) pressure system (6) combination system

3. SPLASH
 In splash lubricating system, oil is splashed up
from the oil pan or oil trays in the lower part of the
crankcase. The oil is thrown upward as droplets and
provides adequate lubrication to valve mechanism,
piston pins, cylinder walls, and piston rings. A scoop
or dipper is made in the lowest part of connecting
rod. When engine runs the dipper dips in the oil
causes oil to splash.
 The splash system is no longer used in automotive
engines. It is widely used in small four-cycle
engines.

4. SPLASH LUBRICATING SYSTEM

5. PRESSURE
 Pressure lubrication systems provide a controlled
flow of clean oil to bearing for less wear and
longer engine life.
 High-efficiency pump in the oil pan supplies
lubricant to the crankshaft and connecting rod
bearing surfaces. The pressure system
incorporates a premium spin-on oil filter. Pressure
lubrication is used on select single cylinder
engines.

6. PRESSURE LUBRICATING SYSTEM

7. COMBINATION
 Combination lubrication system is combination of
splash and pressure lubrication system. In this the
lubricating oil is supplied by a pump under pressure
to main and cam shaft bearings.
 The oil Is also directed in the form of spray from
nozzle or splashed by a scoop or dipper on the big
end to lubricate bearings at the big end of the
connecting rod , crank pin, gudgeon pin, piston rings
and cylinder.

8. COMBINATION LUBRICATING SYSTEM

9. COOLING SYSTEM
 Cooling system is used to control the
temperature of internal combustion engine parts
to prevent overheating and to maintain all
operating dimensions, clearances, and
alignment by circulating coolant, oil and a fan.
Following two types are used for cooling I.C.
engine,
 (1) Air cooling
 (2) Water cooling

10. AIR COOLING
 Air cooling system is generally used in small engine say
up to 15-20 kW and in aero plane engines.
 In this system FINS or EXTENDED surfaces are
provided on engine cylinder walls, cylinder head, etc.
Heat generated due to combustion in the engine
cylinder will be conducted to the fins and when the air
flows over the fins, heat will be dissipated to air.
 The amount of heat dissipated to air depends upon :-
 (1) Amount of air flowing through the fins.
 (2) fin surface area.
 (3) Thermal conductivity of metal used for fins.

11. AIR COOLING SYSTEM

12. WATER COOLING
 In this method, cooling water jackets are
provided around the cylinder, cylinder head,
valve seats etc. The water when circulated
through jackets, it absorbs heat of combustion.
This hot water will then be cooling in the radiator
partially by a fan partially by the flow developed
by the forward motion of the vehicle. The cooled
water is again re-circulated through the water
jackets.

13. WATER COOLING SYSTEM

14. COMPARISON
PETROL ENGINE
 It is S.I. (SPARK
IGNITION) engine.
 Petrol engine are lighter
than diesel engine.
 In petrol engine the
mixture of air and petrol is
drawn by falling piston
during suction stroke.
 Fuel is sent to cylinder
through carburetor.
DIESEL ENGINE
 It is C.I. (COMPRESSION
IGNITION) engine.
 Diesel engine are heavier
and pull heavy loads
easily.
 In diesel engine only air is
drawn by the falling piston
during suction stroke.
 Fuel is sent to cylinder
through fuel injector.

15. THANK YOU