The presentation is on IC Engine Lubricating System.

1. WELCOME TO OUR PRESENTATION
TOPIC: LUBRICATION SYSTEM

2. Presentation Group No: 02
MEC-401| Section: B
Name ID Serial
Md. Masud Rana 16307024 08
Rafiqul Islam 16307039 09
Md Al Amin 16307040 10
Salauddin Kader 16307070 11
Ariful Hasan 16307081 12
Md. Shimoon Hassan 17107002 13
Md. Shahraj Hossain 17107003 14

3. Contents
1. Definition of lubrication
2. Properties of a lubricant
3. Purpose of lubrication
4. Lubrication regions of an engine
5. Lubricating systems
6. Types of lubrication system
7. Components of Lubrication System
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4. WHAT IS LUBRICATION
The action of applying lubricant such as oil or grease to an engine or
component so as to minimize friction and allow smooth movement.
In an IC engine, moving parts rub each other causing wear and tear and
reduces the power almost. so , lubrication is necessary for an IC engine.
Types of lubricant:
➢Solid Lubricants: graphite ,molybdenum ,mica
➢Semi-solid Lubricants: heavy greases
➢Liquid Lubricants: mineral oil obtained by refining petroleum oil,
vegetable oils obtained from olive, linseed, caster and animal oil
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5. PROPERTIES OF LUBRICANTS
➢ Viscosity
❑ It is a measure of the resistance to flow of an oil
❑ It is measured in Saybolt Universal Seconds (SUS)
❑ It is expressed in centistokes ,centipoises and redwood seconds
➢ Viscosity Index
❑ Viscosity of oil decreases with increase in temperature
➢ Cloud Point
❑ If an oil is cooled , it will start solidifying at some time .
❑ temperature at which oil starts solidifying , is called cloud point
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6. PROPERTIES OF LUBRICANTS
➢Pour Point
❑ It is temperature just above which the oil sample will not flow under certain
prescribed conditions
❑ This property is important for operation of engines and substances at low
temperature conditions
➢ Flash Point And Fire Point
❑ The temperature at which vapor of an oil flash when subjected to a naked
flame is called flash point
❑ Fire point is the temperature at which the oil ,it once lit with flame ,will burnt
steadily at least for 5 seconds 6

7. PURPOSES OF LUBRICATION
The main purposes of lubrication are as follow:
oMinimizes power loss by reducing the friction between the moving parts.
oReduces the wear and tear of the moving parts.
oProvides cooling effect to the hot engine parts.
oProvides cushioning effect against vibrations caused by the engine.
oCarries out the internal cleaning of the engine.
oHelps piston rings to seal against high-pressure gases in the cylinder.
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8. LUBRICATION REGIONS OF AN ENGINE
• Cylinder piston and piston rings
• Main bearing
• Crankshaft
• Crank pin and piston pin
• Big end and small end connecting rod
• Camshaft
• Valves
• Timing gears
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9. LUBRICATING SYSTEMS
Lubricating system is a mechanical system of lubricating internal combustion
engines in which a pump forces oil into the engine bearings.
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10. TYPES OF LUBRICATING SYSTEMS
The basic types of lubricating systems are as follows:
1. Petrol Lubrication System
2. Wet-Sump Lubrication System
i. Splash System
ii. Pressure-Feed System
iii. The Splash & Pressure Lubrication System
3. Dry-Sump Lubrication System
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11. PETROL LUBRICATION SYSTEM
➢ This system is used in 2 stroke cycle
engines
➢ The lubrication oil (2% to 3%) is mixed
with the petrol in the fuel tank
➢ The oil and the fuel mixture is inducted
through carburetor
➢ The optimum fuel oil ratio used is 50:1
➢ Petrol gets evaporated and the oil
lubricates the main parts of cylinder
➢ Fuel oil ratio used is important for the
good performance of engine
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12. PETROL LUBRICATION SYSTEM
Advantages:
➢ separate lubricating system is not required
➢ No maintenance cost for lubrication system
➢ Weight of engine is reduced by avoiding separate lubricating system
Disadvantages:
➢If oil is less then there is chance of seizure of the engine
➢More oil makes excess air in the exhaust
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13. WET-SUMP LUBRICATION SYSTEM
➢ In this system a big oil sump is provided at the base of crank case.
➢ From the sump oil is pumped to different parts of the engine
➢ The main types of Wet sump lubrication system are:
• Splash lubrication system
• Pressure lubrication system
• Splash and pressure lubrication system
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14. SPLASH LUBRICATION SYSTEM
Applicable to small four-stroke engines like the engines of lawn mower,
golf carts etc.
The lubricating oil is filled in the sump
Scoop/dippers are attached to the caps on the end of connecting rod
When system moves to Bottom Dead Centre (BDC), scoops dip into the
through and collect oil.
Then the scoop splashes lubricating oil to the piston, cylinder, big end of
connecting rod, main bearing and cam shaft bearing
The splashed oil settles on engine parts and then to sump again
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15. SPLASH LUBRICATION SYSTEM
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16. PRESSURE-FEED SYSTEM LUBRICATION SYSTEM
Applicable to high-speed stationary, marines and most automobile engines
In this system , lubrication is done with the help of pressure pump which is
submerged in the sump
With the help of pressure pump after filtration oil is forced under pressure
to different parts of the engine through oil tubes
From the bearing, oil floats to connecting rod through oil holes between
connecting rod and cam shaft
Then this oil flows to piston pin through oil holes and sprayed over piston,
piston rings, cylinder valves and other parts
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18. SPLASH AND PRESSURE LUBRICATION SYSTEM
• Applicable to medium-speed stationary engines
• Splash system is not sufficient when bearing loads are higher hence
lubricating oil under pressure is supplied by oil pump to main and
crankshaft bearings
• Oil pump also supplies oil under pressure to pipes which directs a stream of
oil against the dippers (scoop) on the connecting rod bearing cups
• Other parts are lubricated by splash of oil by scoop
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20. DRY-SUMP LUBRICATION SYSTEM
➢ Used in aircraft engines and motor cycle
➢ In dry sump , extra oil is stored in a tank outside the engine rather than oil
pan
➢ In this system ,the lubrication oil is passed through the pipes using
scavenging pumps
➢ After lubrication, the oil is again collected by special connecting sections
and passed to heat exchanger for cooling
➢ Scavenging pump has greater capacity than oil feed pump and it is placed
externally to sump
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22. DRY-SUMP LUBRICATION SYSTEM
Advantages:
➢ Improvements to vehicle handling and stability.
➢ Improved engine reliability due to consistent oil pressure.
➢ Increased oil capacity, by using a larger external reservoir than would be
practical in a wet-sump system
➢ Having the pumps external to the engine makes them easier to maintain or
replace
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23. DRY-SUMP LUBRICATION SYSTEM
Disadvantages:
➢ Dry-sump systems add cost, complexity and weight
➢ The extra pumps and lines in dry-sump engines require additional oil and
maintenance
➢ The large external reservoir and pumps can be tricky to position around
the engine and within the engine bay due to their size
➢ Inadequate upper valvetrain lubrication can also become an issue if too
much oil vapor is being pulled out from the area, especially with multi-staged
pumps
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24. COMPONENTS OF LUBRICATION SYSTEM
• Oil sump
• Oil filter
• Piston cooling nozzles
• Oil pump
• Oil galleries
• Oil cooler
• Oil pressure indicator/light
• Oil strainer 24

25. OIL SUMP
• Lowest part of the crank
chamber.
• Provides a covering for the
crankshaft and contains oil in it.
• It is also known as oil pan.
• It is made of steel pressings and
also by aluminum or cast iron.
• It contains drain plug at its
lowest part to drain out the oil.
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26. OIL FILTER
• The function of filter is to
remove the impurities from the
lubricating oil which may
damage the engine bearings.
• It consists of a filtering element
placed in metallic casing.
• At the center of the filtering
element a perforated metal tube
is fitted which collect the filtered
oil and supply it to oil gallery.
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27. OIL PUMP
• Located inside the crankcase .
• Function is to supply oil under
pressure to various engine parts to
be lubricated.
• Types:
• Gear pump
• Rotor pump
• Plunger pump
• Vane pump
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28. OIL GALLERIES
An oil gallery is an internal
passageway in the block of an
automobile engine that conducts
oil to key components such as
the main bearings.
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29. OIL COOLER
• To cool the lubricating oil in heavy
duty engines .
• It is just like a simple heat
exchanger.
• Oil is cooled either by cold water
from the radiator or by the air
stream.
• Water type oil cooler are most
commonly used because they
act as reversible cooler.
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30. OIL PRESSURE INDICATOR/LIGHT
• The level of the oil pressure in the crankcase system.
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31. OIL STRAINER
• It is simply a wire mesh screen.
• It is attached to the inlet of the
pump so that the oil going into the
oil pump is free from impurities.
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32. CONCLUSION
Lubrication must be done properly and right type of lubricant should be
used. Improper or inadequate lubrication of engine will cause serious
trouble such as scored cylinders, worn or burnt out bearing, misfiring
cylinders, dirty spark plug, stuck piston rings, engine deposits and sludge
and excessive fuel consumption.
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