lubrication system automobile

1. Internal Combustion Engines
Presented by – Manmeet Singh
Assistant Professor
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2. Purpose of Lubrication
 Reduce the frictional resistance
Protect the engine against wear.
Serve as a cooling agent by picking up
heat.
Remove all impurities from the
lubricated region.
Form a seal between piston rings and
the cylinder walls to prevent blowby.
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3. Lubrication
Systems
❖ Mist lubrication
system❖ Wet sump lubrication system
❖ Dry sump lubrication system
Four
Stroke
Engines
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Two Stroke
Engines
The wet sump system is employed in relatively
small engines, such as automobile engines,
While the dry sump system is used in large
stationary, marine and aircraft engines.

4. Mist Lubrication Systems
In two-stroke engines, the charge is compressed
in the crankcase, and as such it is not suitable to
have the lubricating oil in the sump.
Therefore, such engines are lubricated by adding 3
% to 6 % oil in the fuel tank itself.
The oil and fuel mixture is inducted through the
carburetor.
The fuel gets vaporized and the oil, in the form of
mist, goes into the cylinder through the crankcase.
The main advantage with this system lies in the
simplicity and low cost as the system does not
require any oil pump, filter etc.
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5. WET SUMP LUBRICATION SYSTEMS
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In the wet sump system, the bottom of the
crankcase contains an oil sump (or pan) that
serves as the oil supply reservoir.
Oil dripping from the cylinders and bearings
flows by gravity back into the wet sump
where it is picked up by a pump and re-
circulated through the engine lubricating
system.
The types of wet sump systems used are:
1. the splash and circulating pump system
2. the splash and pressure system
3. the full force-feed system

6. SPLASH AND CIRCULATING PUMP SYSTEMD:IDM
VIDEODOWNLOADEDMPEONLINE - 18-SPLASH
LUBRICATION.SWF.MP4
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C a m s ha f t
C o n n e c tin g ro d
be a ri n g s
M a in be a r in g
m a in
b e a rin g
O il
trou g h s
Lo w e r
o il p a n
O il p u m p
O il S t r a iner

7. SPLASH AND PRESSURE SYSTEM
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C a m s h a ft
C o n n e c tin g ro d be a rings
M a in be a r in g
m a in
be a rin g
O il p u m p
O il S t r a iner

8. FULL FORCE FEED SYSTEMD:IDM
VIDEODOWNLOADEDAUTOMOTIVE BASICS -
HOW ENGINE LUBRICATION SYSTEM
WORKS.MP4
Camshaft
Oil pump
Oil Strainer
Header main
line bearing
End leakage
from rod
connecting rod bearing
Main bearing
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9. DRY SUMP LUBRICATING SYSTEM
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Oil
Cooler
Pressure
release
valve
Vent
Filter By-P ass
Presuure
relief valve
Filter
Scavenging pum p
Strainer
E ngine crankcase
Oil pum p
To
Bearings
Supply
Tank
D ry sump

10. Properties of Lubricating Oil
❖The oil used in an engine must serve as
a lubricant, a coolant and an agent for
removing impurities.
❖It must be able to withstand high
temperatures without breaking down. The
oil must operate over a good range of
temperature.
❖They must not oxidize on the chamber
walls, piston crown or at the piston
rings.
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Oil
shoul
d
have high
fil
m
strength to
prevent metal-to-metal contact even
under extreme loads.

11. PROPERTIES OF LUBRICATING OIL
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(a)Viscosity: The lubricating oil
should have the correct viscosity
so that it flows easily to all the
moving parts.
❖If oil viscosity is too high, more
work is required to pump it and
to shear it between the moving
parts. This results in greater
friction work, reduced brake
work and hence reduced power
output.
❖Viscosity is highly
on temperature,
with decreasing
dependent
increasing
temperature.
❖The fuel consumption may
increase by as much as 15 %.

12. Selecting right viscosity- Rating of Lubricating Oil
engines use high viscosity grades oil.
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❖ Lubricatin
g
oil
i
s
generally rated using a
viscosity scale established by the SAE
.Commonly used viscosity grades are:
SAE 5
SAE 10
SAE 20
SAE 30
SAE 40
SAE 45
SAE 50
❖The oil with lower viscosity grades is less
viscous and is used in cold-weather operation.
Modern high temperature, high speed, close
tolerance

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RATING OF LUBRICATING OIL – VISCOSITY INDEX
❖When certain polymers are added to oil, the
temperature dependency of oil viscosity is reduced.
These oils have low viscosity grades when they are
cold and higher as they become hot.
❖As for example, SAE 10W-30
means that the oil has a grade 10
when it is cold (W stands for winter)
and 30 when it is hot.
❖Commonly used oils in this
category are:
SAE 5W-20 SAE 10W-40
SAE 5W-30 SAE 10W-50
SAE 5W-40 SAE 15W-40
SAE 5W-50 SAE 15W-50
SAE 10W-30 SAE 20W-50

14. Rating of Lubricating Oil
(b)Specific Gravity: This property is of little
importance except as an indicator of weight
and volume. The specific gravity of oil varies
from 0.85 to 0.96.
(c)Pour Point: It indicates the temperature
below which the lubricating oil loses its fluidity
and will not flow or circulate in the system. This
characteristics of the oil is important at low
temperature.
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15. Rating of Lubricating Oil
(d) Oxidation Stability: Oxidation stability of an
oil is its resistance to oxidation. Due to
oxidation, oil forms deposits on the piston
rings, and thereby loses its lubricating
property. Some inhibitors are used to
counteract these tendencies.
(e) Acidity and Neutralization
lubricating oil should have low
Number:
Th
e acidity.
The
neutralization number is a measure of acidic or
alkaline contents of oil.(TAN Number)
(f) Oiliness: Oiliness is responsible for the
boundary layer of molecules that can adhere or
cling to a metal surface and provide lubrication
after most of the oil gets displaced or squeezed
out.
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16. CLASSIFICATION OF
LUBRICANTS
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• Animal
• Vegetable
• Mineral
• Synthetic

17. Types of Lubricating Oil
Q Vegetable oils have been used in the
past, especially for racing car engines.
The main advantages of these oils are their
high film strength, and they have a good
lubricity.
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Q Later, specially formulated
have replaced their use
mineral
in
oil
s
highperformance engines.
Mineral oils are most readily available and
cost effective. They readily respond to
additives, and can be produced in a wide
range of viscosities.
The main disadvantage lies with its wax
content that affects cold performance and
can clog filters.

18. ANIMAL LUBRICANTS
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• Lubricants with animal
origin:
– Tallow
– Tallow oil
– Lard oil
– Neat’s foot oil
– Porpoise oil
• These are highly stable at normal
temperatures
• Animal
lubricant
s
may not be used
fo
r
internal combustion because they
produce fatty acids.

19. VEGETABLE LUBRICANTS
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of mineral• There are three
classifications
lubricants:
– Solid, Semisolid, Fluid
• Examples of vegetable lubricants are:
– Castor oil, Olive oil, Cottonseed oil
• Animal and vegetable oils have a lower
coefficient of friction than most mineral oils
but they rapidly wear away steel.
Mineral Lubricants
• These lubricants are used to a large extent
in the lubrication of aircraft internal
combustion engines.

20. SYNTHETIC
LUBRICANTS
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• Because of the high operating
temperatures of gas-turbine engines,
it became necessary to develop
lubricants which would retain
theircharacteristics at temperatures that
cause petroleum lubricants to
evaporate and break down.
• Synthetic lubricants do not break
down easily and do not produce
coke or other deposits.

21. Additives
❖ Corrosion and Rust Inhibitors
❖ Anti-foam Agents
❖ Detergent-Dispersants
❖ Pour Point Improvers
❖ Oiliness and Film-strength
Agents
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22. Conclusions
In order to minimize friction between the
moving parts and hence wear, lubrication
system in an engine plays a significant
role. The lubrication system is designed to
deliver clean oil at the correct temperature
and pressure to every part of
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the engine. Lubricatin
g
oil can be
supplied to the various engine
components by a splash system or by a
pressurized system or a by a combination
of both. In two-stroke engines, oil is mixed
with the fuel itself.