2. Friction generates heat
Some part of energy applied in
rubbing the two surfaces is thus lost
It is essential to reduce friction
The fluids which minimize friction
are called lubricants
The main purpose of a lubricant is to
save mechanical energy
3. Functions of lubricating oilFunctions of lubricating oil
Reduces friction between the moving parts
Reduces wear of the moving parts as far as
possible
Acts like a cooling medium
Reduces noise between striking surfaces
To provide sealing action
To provide cushioning effect
To provide cleaning action
4. Viscosity – high viscosity index (VI)
Petroleum lube oils – VI - 100-100
Can be increased to 120-130 by means of additives
Physical stability
Chemical stability
Resistance against corrosion
Flash point – should be high
Cleanliness
Resistance against extreme pressure
Requirements of lubricantsRequirements of lubricants
5. Types of lubricantsTypes of lubricants
According their origin oils are classified as followsAccording their origin oils are classified as follows
Animal oils:Animal oils:
Animal oils: obtained from Animal fat, Easily oxidizedAnimal oils: obtained from Animal fat, Easily oxidized
and become gummy after some useand become gummy after some use
Vegetable oilsVegetable oils
produced from Seeds ,fruits of plants, trees etc. Easilyproduced from Seeds ,fruits of plants, trees etc. Easily
oxidized and become gummy after some useoxidized and become gummy after some use
6. Types of lubricantsTypes of lubricants
According their origin oils are classified as followsAccording their origin oils are classified as follows
Mineral oilsMineral oils
derived from petroleumderived from petroleum
Following are advantages over above two oilsFollowing are advantages over above two oils
Greater chemical stability at higher temperturesGreater chemical stability at higher tempertures
More plentiful and cheaperMore plentiful and cheaper
Synthetic lubricantsSynthetic lubricants
Examples:silicon fluids,poly glycol ethers etcExamples:silicon fluids,poly glycol ethers etc
Following are advantages over mineral oilsFollowing are advantages over mineral oils
Higher Considerably less oil consumptionHigher Considerably less oil consumption
7. Types of lubricantsTypes of lubricants
According their origin oils are classified as followsAccording their origin oils are classified as follows
Greases: they are suspension of metallic soapsGreases: they are suspension of metallic soaps
dispersed in lubricating oil.dispersed in lubricating oil.
These are used where retention of liquid lubricants isThese are used where retention of liquid lubricants is
difficult and where high temperatures are encountereddifficult and where high temperatures are encountered
eg: in axleseg: in axles
Solid lubricants – Graphite is used as cylinderSolid lubricants – Graphite is used as cylinder
lubricant and ,it is stable at high temperature and lowlubricant and ,it is stable at high temperature and low
coefficient of friction. Use of graphite is that it fill thecoefficient of friction. Use of graphite is that it fill the
pores of the metal and makes it friction free.pores of the metal and makes it friction free.
8. Viscosity ratingViscosity rating
According to The Society of Automotive Engineers
(SAE)
0W,5W,10W,20W,25W – for winter use
10,15,20,30,40,50,60,80,100,150,200,300 – for summer
use
Multigrade oils – 10W/30
First Number in the oil weight represents the oil's viscosity at 0First Number in the oil weight represents the oil's viscosity at 0
degrees F(-18 ºC). The lower the first number in an oil's weight, thedegrees F(-18 ºC). The lower the first number in an oil's weight, the
thinner it is at low temperatures. Oil that is thinner at coldthinner it is at low temperatures. Oil that is thinner at cold
temperatures is typically better suited for winter driving.temperatures is typically better suited for winter driving.
The second number, the number after the W, represents oil's viscosityThe second number, the number after the W, represents oil's viscosity
at 210 degrees F(99 ºC). The higher the number, the thicker the oilat 210 degrees F(99 ºC). The higher the number, the thicker the oil
will stay at high temperatures. Thicker oil at high temperatures iswill stay at high temperatures. Thicker oil at high temperatures is
better for summer driving.better for summer driving.
9. Oil additivesOil additives
The chemical substances which are added to the
lubricating oil either to reinforce some of its natural
properties or to provide it with certain new
properties which it does not possess originally
Oxidation inhibitors – amines, sulphides or phenols
with metals like tin, zinc or barium
Corrosion inhibitors - oxidation inhibitors with
metal salts
Detergents – high temperature deposits – gums and
varnishes
and dispersants – low temp deposits – cold sludge
Anti scuff additives - to polish moving parts like
piston, cylinder walls, cams etc.,
Viscosity index improvers
Anti foaming additives – polyorganosiloxanes
10. Parts which require lubricationParts which require lubrication
Main crankshaft bearing
Big end bearings
Gudgeon pin bearings
Piston rings and cylinder walls
Timing gear
Camshaft and camshaft bearings
Valve mechanism
Electrical equipment
12. Petroil systemPetroil system
Used generally for two-stroke enginesUsed generally for two-stroke engines
Simplest of all types of lubrication systemsSimplest of all types of lubrication systems
Certain amount of lubricating oil is mixedCertain amount of lubricating oil is mixed
with the petrol itself (2-3% of oil)with the petrol itself (2-3% of oil)
less: Insufficient lubrication causes damageless: Insufficient lubrication causes damage
to engineto engine
more: excessive carbon depositsmore: excessive carbon deposits
13. Splash system
Con rod
or
scoop
•Employed for motorcycles
•Cheapest method
•The scoop causes the oil
to splash on the cylinder
walls each time it passes
through its BDC position
•This affects the lubrication
of engine walls, gudgeon
pin, crank shaft bearings,
big end bearings etc
14. Pressure system of lubricationPressure system of lubrication
Universally used in modern car enginesUniversally used in modern car engines
An oil pump takes the oil from the wet sumpAn oil pump takes the oil from the wet sump
through a strainer and delivers it through athrough a strainer and delivers it through a
filter to the mail oil gallery at a pressure offilter to the mail oil gallery at a pressure of
200-400 kPa200-400 kPa
23. Oil pumpsOil pumps
Its function is to supply oil
under pressure to the various
engine parts
Generally located inside the
crank case below the oil level
24. Gear pumpGear pump Its construction isIts construction is
very simplevery simple
One gear is drivenOne gear is driven
from cam or crankfrom cam or crank
shaftshaft
The other gear is freeThe other gear is free
to revolve on its ownto revolve on its own
bearingbearing
The oil is drivenThe oil is driven
between the gearbetween the gear
teeth from the inletteeth from the inlet
side and forced outside and forced out
the outlet sidethe outlet side
Universally used type pump
It can deliver oil at a pressure
of about 2-4kg/cm2
25.
26.
27. Rotor oil pump
The two gears
mesh internally
The oil is
displaced from
the inlet to the
outlet side in
the same way
as in the gear
pump
28. The cam shaft rotates the drive shaft which rotates
the inner rotor which turns the outer rotor
29. Plunger pumpPlunger pump
The plunger
reciprocates in
the pump body
While moving up
the plunder sucks
oil from
the inlet
And while
moving down it
forces out the oil
from the outlet
Used in splash
system
30. Vane pumpVane pump
Vane pumps are used for
liquid transfer applications
Vanes extend from slots in
the rotor, sweeping liquid
through a cam-shaped
cavity. The vanes provide
very low slip and high
volumetric efficiency.
31. Oil filtersOil filters
An oil filter is a device used to
decontaminate oil that contains
suspended impurities.
A major application is in forming part
of the lubrication system of engines in
which filters are typically detachable
units due to the need for regular service
or replacement.
The filtration of oil in engines is
essential for enhancing longevity and
performance.
37. Oil pressure gaugesOil pressure gauges
Electrically operated
Oil pressure warning light and switch
Oil pressure warning system
38.
39. Engine ServicingEngine Servicing
Automobile service is necessary toAutomobile service is necessary to
keep the motor vehicles in akeep the motor vehicles in a
condition ofcondition of
SafetySafety
ReliabilityReliability
ComfortComfort
CleanlinessCleanliness
Performance andPerformance and
Economy
40. It includesIt includes
High pressure lubricationHigh pressure lubrication
Power washingPower washing
Wheel alignmentWheel alignment
Wheel balancingWheel balancing
Body and wing repairsBody and wing repairs
Transmission service and testingTransmission service and testing
Repair of automobile engine andRepair of automobile engine and
electrical equipmentelectrical equipment
41. By servicing and tuning of theBy servicing and tuning of the
engineengine
Greater powerGreater power
Faster acceleration andFaster acceleration and
High road speedsHigh road speeds
can be obtainedcan be obtained
42. Types of serviceTypes of service
Self diagnosed servicesSelf diagnosed services
LubricationLubrication
Washing bodyWashing body
Wing repairsWing repairs
Repairs of brakes, tyresRepairs of brakes, tyres
Steering alignment etcSteering alignment etc
Performance servicesPerformance services
For correcting engine performance andFor correcting engine performance and
Electrical troublesElectrical troubles
43. Procedure of engine serviceProcedure of engine service
Engine disassemblyEngine disassembly
Cleaning of partsCleaning of parts
Inspection of partsInspection of parts
Condition of engine partsCondition of engine parts
44. Engine DecarbonizationEngine Decarbonization
Engine decarbonization is a process utilizingEngine decarbonization is a process utilizing
chemicals to remove soft and semi-hardenedchemicals to remove soft and semi-hardened
gum, varnish, resin and carbon depositsgum, varnish, resin and carbon deposits
from thefrom the air/fuel delivery systemsair/fuel delivery systems andand
combustion chamberscombustion chambers of internal combustionof internal combustion
engines.engines.
Benefits of the service include improved fuel economy,Benefits of the service include improved fuel economy,
engine performance and reduced emissions.engine performance and reduced emissions.
This process is performed to reduce or removeThis process is performed to reduce or remove
depositsdeposits
Recommendations will be time and mileage based.Recommendations will be time and mileage based.
45. A wire brush is used to remove heavyA wire brush is used to remove heavy
carbon deposits from cylinder headscarbon deposits from cylinder heads
and valves. {Some special wire brushand valves. {Some special wire brush
operates on an electric drill motor}operates on an electric drill motor}
Scrapers should be used to clean theScrapers should be used to clean the
piston heads and groovespiston heads and grooves
47. Nitriding is a process that infuses
nitrogen ions into the surface of steel to
increase its surface hardness on a
molecular level.
Nitriding offers the end-user a uniform
hardened layer without internal stresses,
and that’s what makes it perfect for
crankshafts.
48. Engine ReboringEngine Reboring
A cylinder is rebored because:A cylinder is rebored because:
1. The piston to cylinder bore clearance1. The piston to cylinder bore clearance
is too largeis too large
2. There are deep scratches, grooves in2. There are deep scratches, grooves in
the bore that hinder cylinder sealingthe bore that hinder cylinder sealing
3. The bore is out round compared to3. The bore is out round compared to
the piston.the piston.
49. To increase the power of anTo increase the power of an
engine we can increase theengine we can increase the
cylinder capacity. cylinder capacity.
The best way to increase theThe best way to increase the
cylinder capacity of an engine iscylinder capacity of an engine is
by physically making eachby physically making each
cylinder a larger diameter. cylinder a larger diameter.
50. Engine block reboring meansEngine block reboring means
that the engine block isthat the engine block is
machined to a bigger sizemachined to a bigger size
cylinder.cylinder.
It smoothes out the bores andIt smoothes out the bores and
makes them like new.makes them like new.
51. Blow-byBlow-by
If the cylinderIf the cylinder
becomes oval due tobecomes oval due to
wear some of the gaswear some of the gas
escapes through theescapes through the
piston rings.piston rings.
The gas which leaksThe gas which leaks
through the pistonthrough the piston
rings is calledrings is called blow-blow-
byby..
It reduces theIt reduces the
efficiency of an engine.efficiency of an engine.
52. Effects of piston blow-byEffects of piston blow-by
The partially burnt A/F mixture
contaminate the lube oil in the
crank case, which may deteriorate
the performance of the engine
lubricating oil
This A/F mixture may cause an
explosion in the crank case
Corrosion of engine parts
53. Crankcase ventilationCrankcase ventilation
A steady flow of air is carried
through the engine crank case
which carries away the products of
combustion along with it in the
form of vapour or mist.
Methods
1. Road draft system
54. Road draft system
The air stream due to motion of the vehicle, and
supplemented by the cooling fan enters the engine
at the top and is then circulated in the crank case
where it carries the vapor after which it comes out
through the outlet and goes into the atmosphere
55. The Positive Crankcase Ventilation
valve, or PCV valve, is a one-way
valve that ensures continual
evacuation of gases from inside a
gasoline internal combustion
engine's crankcase.
Positive Crank case ventilationPositive Crank case ventilation
57. Positive Crank case ventilationPositive Crank case ventilation
Fuel and
air saver
technolo
gy
(FAST)
58. ReferenceReference
Automobile engineering vol 2 by kirpal singhAutomobile engineering vol 2 by kirpal singh
unit-6-lubrication and lubricants page numberesunit-6-lubrication and lubricants page numberes
193193
Editor's Notes
Physical stability: it should not vaporize beyond certain limit
Chemical stability: there should not be any tendency to for oxide formation.(oxidation products being sticky substances clog the lines)
Resistance against corrosion: oil should not have any tendency to corrode the pipe lines,crank case etc
Flash point – should be high to avoid flashing of oil vapors
Cleanliness: it should be clean and stable itself so that the crank case and oil lines are kept clean
Resistance against extreme pressure: when oil is subjected to high pressures for example in bearings oil may be driven out.oil should have sufficient resistance against this tendency.
Animal oils: obtained from Animal fat,Easily oxidized and become gummy after some use
Vegetable oils: produced from Seeds ,fruits of plants,trees etc.Easily oxidized and become gummy after some use
Mineral oils:derived from petroleum
Following are advantages over above two oils
Greater chemical stability at higher tempertures
More plentiful and cheaper
Synthetic lubricants-Examples:silicon fluids,poly glycol ethers etc
Following are advantages over mineral oils
Higher Considerably less oil consumption
Animal oils: obtained from Animal fat,Easily oxidized and become gummy after some use
Vegetable oils: produced from Seeds ,fruits of plants,trees etc.Easily oxidized and become gummy after some use
Mineral oils:derived from petroleum
Following are advantages over above two oils
Greater chemical stability at higher tempertures
More plentiful and cheaper
Synthetic lubricants-Examples:silicon fluids,poly glycol ethers etc
Following are advantages over mineral oils
Higher Considerably less oil consumption
Animal oils: obtained from Animal fat,Easily oxidized and become gummy after some use
Vegetable oils: produced from Seeds ,fruits of plants,trees etc.Easily oxidized and become gummy after some use
Mineral oils:derived from petroleum
Following are advantages over above two oils
Greater chemical stability at higher tempertures
More plentiful and cheaper
Synthetic lubricants-Examples:silicon fluids,poly glycol ethers etc
Following are advantages over mineral oils
Higher Considerably less oil consumption