Engine lubrication system

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The engine lubrication system provides:

• reducing friction and increasing the mechanical efficiency of the engine;
• reduction of wear of rubbing parts;
• cooling of engine parts and removal of wear products from engine parts.

Lubrication of rubbing parts, along with the selection of materials and the type of treatment of their surfaces, effectively increases the durability of the engine. The lubrication system also cleans the circulating oil from mechanical and other harmful impurities.

The oil reserve necessary for normal operation of the engine is located directly in the crankcase. Oil filling into the engine crankcase is carried out through the oil filler neck, hermetically sealed with a lid. The oil level is controlled by the marks on the pointer. Waste oil is drained from the system through a hole closed with a screw plug. Oil system capacity 3.75 l. Oil pressure on a warm engine at an average speed of 3.5-4.5 kgf / cm².

The engine lubrication system is combined: under pressure and splashing.

Main and connecting rod bearings, camshaft and oil pump drive shaft bearings, camshaft lobes and oil pump drive gear bushing are lubricated under pressure.

Oil flowing from the gaps and splashed by moving parts lubricates the cylinder walls, pistons with piston rings, piston pins in the piston bosses, the timing chain, the valve lever bearings, and the valve stems in their guide bushings.

The lubrication system includes: an oil pump, an inlet pipe with a small filter mesh attached to the pump housing, a full-flow oil filter mounted on the left front side of the engine, an oil pressure reducing valve built into the inlet pipe, an electric low oil pressure sensor and on the VAZ engine -2103 oil pressure gauge.


The oil pressure sensor 19 is connected to the signal lamp 20 on the instrument panel, which lights up when the oil pressure drops to 0.4-0.8 kgf/cm². When the engine is running with a good lubrication system, the lamp should go out (if the engine is not overheated). On the VAZ-2103 car, in addition to the control lamp, there is an oil pressure indicator 22 with a sensor 23 installed in the rear of the cylinder block, on an adapter screwed into the oil channel 18.

The circulation of oil during engine operation is as follows. The oil pump 1, driven by a pair of helical gears, sucks oil from the crankcase through the filter screen of the oil intake pipe 2 and delivers it through channel 3 to the full-flow filter. The filtered oil through channels 4 and 6 enters the longitudinal main channel 18, which runs along the block, on the left side, and from there through channels 7 and 8 drilled in the cylinder block, it penetrates to the main bearings of the crankshaft and the front bearing of the oil pump drive shaft. Oil is supplied to the central support of the camshaft through channels 17 drilled in the cylinder block, 16 in the head and 15 in the camshaft bearing housing.

The block head gasket has a copper-lined hole through which oil flows from block channel 17 to head channel 16.

The main bearing shells have holes through which oil enters the annular grooves of the shells. From the grooves, part of the oil goes to lubricate the main bearings, and the other through channels 24 drilled in the necks and cheeks of the crankshaft to the connecting rod bearings, and from them through the holes 47 in the lower heads of the connecting rods, a jet of oil enters the cylinder mirror at the moment the bearing hole coincides with channel in the crankpin.


The oil that has approached the central bearing of the camshaft through a groove in the bearing journal enters the central channel 13 of the camshaft, and from the channel through the holes in the cams and in the bearing journals - to the cams, levers and shaft bearings. Oil from the first bearing of the oil pump drive roller is supplied to the second one through channels 9 drilled in the roller itself. Oil is supplied to the oil pump drive gear bushing through a separate channel from the block cavity in front of the oil filter. The remaining parts are lubricated by splashing and gravity.

The timing chain is lubricated with oil that comes out of the front camshaft support and the front bushing of the oil pump drive shaft, and then sprayed by centrifugal force through the radial holes 11 on the sprockets of these shafts.

In order to ensure the necessary oil pressure in the line when the engine is running in any mode, as well as to compensate for the oil consumption that increases with engine wear, the oil pump has an excess capacity.

To prevent an increase in oil pressure above the allowable level, a pressure reducing valve is installed in the system, which bypasses excess oil into the oil receiver.

Oil pump 1 (see engine cross section) - gear type, installed inside the oil pan and fastened to the cylinder block with two bolts. The drive gear of the pump is fixedly fixed on the shaft, and the driven gear rotates freely on the axis pressed into the housing. The oil enters the pump through the oil intake pipe, passing through the filter mesh.


The oil filter is screwed onto the fitting and pressed against the annular collar on the block. The tightness of the connection is ensured by a rubber gasket installed between the filter cover and the block shoulder. The oil enters the filter through hole 25 and, having passed the filter element, exits into the main line of the block through the central hole 27 and the mounting fitting.

The filter has an anti-drain valve that prevents oil from draining from the system when the engine is stopped, and a bypass valve that operates when the filter element is clogged.

Oil filtration is performed by a paper element 28 and a non-woven liner. The filter insert cleans the oil more coarsely than the paper element and cleans the oil when starting a cold engine, when thickened oil does not pass through the paper element.

To ensure effective oil filtration, every 10,000 km of run, i.e. when changing the engine oil, the filter must be replaced.

During engine operation, some exhaust gases enter the crankcase. When starting the engine, gasoline vapors also condense in the cylinders, which, getting into the crankcase, dilute the oil and impair its lubricating properties. The water vapor present in the exhaust gases, condensing in the crankcase, foams the oil and leads to the formation of thick and sticky emulsions, and in combination with sulfur dioxide form acids that corrode the working surfaces of engine parts and accelerate their wear.

To remove gases and gasoline vapors from the crankcase, which increases the service life of the oil and increases the durability of the engine, forced crankcase ventilation is used. It also provides fresh air to the crankcase. Fresh air sucked in through pipe 35 passes filter element 36 of the crankcase ventilation system and enters the engine crankcase through pipe 30. Exhaust gases and gasoline vapors are sucked out of the crankcase through hose 42.

To prevent flames from entering the crankcase when «shot» in the carburetor, a flame arrester 41 is installed in the rod. In the exhaust hose, crankcase gases pass through the oil separator 45; the oil separated from the gases flows down the tube into the oil sump.

The body of the oil separator 46 in the tide of the cylinder block is closed with a cover 44.

To protect carburetor parts from resin deposits, crankcase gases are discharged through pipe 43 into the throttle space of the carburetor.

Care of the ventilation system consists in periodic flushing of its devices and changing the filter 37.