lubrication system of icengine

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Need for Lubrication:

Need for Lubrication In an I.C. engine, moving parts rub against each other causing frictional force. Due to the frictional force, heat is generated and the engine parts wear easily. Power is also lost due to friction, since more power is required to drive an engine having more friction between rubbing surfaces. To reduce the power lost and also wear and tear of the moving part substance called lubricant is introduced between, the rubbing surfaces.

Functions of a Lubricant:

Functions of a Lubricant Lubricant reduces friction between moving part. It reduces wear and tear of the moving parts. It minimizes power loss due to friction. It provides cooling effect. While lubricating it also carries some heat from the moving   parts and delivers it to the surroundings through the bottom of the engine (crank case). It helps reduce noise created by the moving parts.

Engine parts to be lubricated:

Engine parts to be lubricated Crank shaft Crank pin Big and small end of the connecting rode Piston pin Internal surfaces of cylinder walls Piston rings Valve mechanisms Cam shaft etc.

Types of lubrication system:

Types of lubrication system Petrol lubrication system or Mist lubrication system . Wet sump lubrication system. Dry sump lubrication system.

Petrol Lubrication System :

Petrol Lubrication System This system of lubrication is used in scooters and motor cycles. About 3% to 6% of lubricating oil is added with petrol in the petrol tank. The petrol evaporates when the engine is working. The lubricating oil is left behind in the form of mist. The parts of the engine such as piston cylinder walls, connecting rod are lubricated by being wetted with the oil mist.

Two – Stroke I.C Engine:

Two – Stroke I.C Engine


Disadvantages If the added oil is less, there will not be sufficient lubrication and even result in seizure of the engine. If the added oil is more, it will lead to excess exhaust smoke and carbon deposits in the cylinder, exhaust parts and spark plugs.

Wet sump Lubrication System:

Wet sump Lubrication System Engine Lubrication Two types of wet sump engine lubrication systems are used in internal-combustion engines. They are: Splash system The pressure-feed system.

PowerPoint Presentation:

The pressure-feed system, with small modifications, is the more popular for more popular for modern automobile engines . The splash system is used on most lawn mower and outboard engines. A wet-sump system is simple, low cost, and light weight. That's why virtually every production engine in the world uses wet-sump lubrication.

Pressure – feed system:

Pressure – feed system In the pressure-feed system, oil is forced by the oil pump through oil lines and drilled passageways. The oil, passing through the drilled passageways under pressure, supplies the necessary lubrication for the crankshaft main bearings, the connecting-rod bearings piston-pin bushings, camshaft bearings, valve lifters, valve push rods, and rocker studs. Oil passing through the oil lines is directed to the timing gears and the valve rocker shafts in order to lubricate these parts.

Pressure feed system:

Pressure feed system

Pressure feed system:

Pressure feed system

PowerPoint Presentation:

The cylinder walls are lubricated by oil thrown off the connecting-rod and piston-pin bearings. Some engines have oil spit holes in the connecting rods that line up with drilled holes in the crankshaft journal during each revolution, and through or spit a steam of oil onto the cylinder walls. Since the oil in the passageways is under pressure, each time the drilled holes in the crankshaft and connecting rod line up with the holes in the bearings, the pressure forces the oil through these drilled passages into the crankshaft and connecting rod, lubricating their respective bearings.

PowerPoint Presentation:

After the oil has been forced to the area requiring lubrication, it falls back down into the oil pan ready to be picked up again and returned through the system. As the oil falls, it is frequently splashed by the moving parts onto some other part requiring lubrication.

The Splash system:

The Splash system The splash system is used only on small four-stroke-cycle engines such as lawn mower engines. As the engine is operating, dippers on the ends of the connecting rods enter the oil supply, pick up sufficient oil to lubricate the connecting-rod bearing, and splash oil to the upper parts of the engine. The oil is thrown up as droplets, or fine spray, which lubricates the cylinder walls, piston pins and valve mechanism.

Splash system:

Splash system

Dry Sump Lubrication System:

Dry Sump Lubrication System In a wet sump, the oil pump sucks oil from the bottom of the oil pan through a tube, and then pumps it to the rest of the engine. In a dry sump , extra oil is stored in a tank outside the engine rather than in the oil pan. There are at least two oil pumps in a dry sump -- one pulls oil from the sump and sends it to the tank, and the other takes oil from the tank and sends it to lubricate the engine. The minimum amount of oil possible remains in the engine.

Dry sump Lubrication:

Dry sump Lubrication

PowerPoint Presentation:

A dry-sump system has several advantages over wet, but the main one is additional power. Because there is only a minimum of oil in the pan, windage‚oil clinging to or splashing against the rotating assemblies of the engine is greatly reduced.

PowerPoint Presentation:

In addition to evacuating oil from the pan, the external oil pump creates a vacuum inside the pan and block that further increases horsepower by improving ring seal. Other advantages of a dry-sump system are increased oil capacity because of the external tank, the ability to easily add remote oil coolers, and because the pan doesn‚store oil, it can be quite shallow to allow for lower engine placement.


Disadvantages A dry-sump system is More complicated, More expensive, and Heavier, but it offers continuous lubrication under all conditions and the promise of increased power through reduced windage .





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