Gasoline engines
In-line petrol engines are mounted transversely at the front of the vehicle. The transmission assembly is located to the left of the engine and transmits the torque developed by the latter to the front wheels of the car.
The cylinder block is made of aluminum alloy and equipped with dry liners.
Observe the prescribed tightening torques for screwed connections, as cast aluminum is a soft material and overtightening component fasteners can damage the threaded holes!
The crankshaft rotates in main bearings equipped with plain bearings. Thrust half rings regulating the axial play of the shaft are mounted on the central support of the shaft.
The connecting rods are mounted on the working journals of the crankshaft equipped with plain bearings and horizontally cut lower heads. The connecting rods are attached to the pistons by means of piston pins planted in their upper heads - in the pistons the pins have a floating fit. The aluminum cast pistons are equipped with three piston rings, two compression rings and one (lower) oil scraper.
The camshaft rotates in a bed mounted on top of the cylinder head and is driven by the crankshaft via a rubber toothed belt (the same belt is used to drive the water pump). DOHC engines use two camshafts, also driven by a rubber toothed belt. The eccentric cams of the camshaft act on the valve actuator levers, the working ends of which rest against the ends of the spring-loaded valve stems threaded into the guide bushings and equipped with oil caps. Opposite ends of the levers rest on hydraulic compensators that automatically adjust valve clearances.
The engine lubrication system is powered by a gear oil pump driven by the crankshaft trunnion. Oil is drawn through a strainer-equipped oil pick-up from the engine sump and filtered by a full-flow replacement oil filter. The oil moves along the oil flows provided in the casting of the block and is distributed in two main directions: to the bearings of the crankshaft and camshaft. Oil is supplied to the bearings under pressure through special drillings in the shaft bodies. Lubrication of the camshaft cams and valve components, as well as other internal engine components, is carried out by the splash method.
General scheme of operation of the engine lubrication system
1 - gear (rotary) oil pump
2 - Oil intake
3 - Oil pan
4 - Full flow oil filter
5 - Pressure reducing valve
6 - Main oil flow
7 — a radical neck of a cranked shaft
8 - Connecting rod neck of the crankshaft
9 - Maslotok vertical oil supply
10 - Camshaft neck Crankcase gases are removed from the engine block using a semi-closed ventilation system. Gases are discharged through the cover of the gas distribution mechanism and enter the intake pipeline through a special hose.
SOHC diesel engines
Engines 4-cylinder in-line, 8-valve, single overhead camshaft (SOHC), installed transversely in front of the vehicle. The transmission assembly is attached to the engine on the left and transmits torque to the front wheels.
The cylinder block is made by cast iron with cylinders molded directly in its body (block with dry sleeves).
The crankshaft rotates in five main bearings equipped with plain bearings. Thrust half rings regulating the axial play of the shaft are planted in the upper half of the central (third) supports.
The connecting rods are mounted on the shaft with their lower horizontally cut heads equipped with plain bearings. Cast aluminum pistons are connected to the connecting rods by means of piston pins floating freely in the upper heads of the connecting rods and fixed in the piston bosses with retaining rings. Each piston is equipped with three piston rings - two compression and one (lower) oil scraper.
The intake and exhaust valves are spring-loaded and move in guide bushings pressed into the cylinder head.
The camshaft is driven from the crankshaft by means of a toothed belt and rotates directly in the block head. The valve drive is carried out from the camshaft using drive levers installed directly under the cams. The selection of valve clearances is carried out automatically by equipping the support legs of the drive levers with hydraulic compensators.
The lubrication system is organized similarly to that described above for gasoline engines, with the only difference being that in order to increase the intensity of cooling of the piston bottoms, an oil sprayer is installed in the base of each of the cylinders of the block. To maintain normal oil temperature at increased loads, the engine is additionally equipped with an oil cooler.
All engines
The list of repair work performed without removing the engine from the car
The following repairs can be carried out without removing the engine from the vehicle:
- Compression check;
- Removal and installation of the cover of the gas distribution mechanism;
- Removal and installation of the timing cover;
- Removal and installation of timing drive components (belt/chains, cogwheels/sprockets);
- Removal and installation of a camshaft (ov) and valve levers / pushers);
- Removal and installation of the cylinder head;
- Removal and installation of pistons with connecting rods *;
- Removal and installation of the oil pan;
- Removal, refurbishment and installation of the oil pump;
- Removal and installation of the oil cooler (with appropriate equipment);
- Replacement of crankshaft seals;
- Checking the condition and replacing the suspension mounts of the power unit;
- Removal, condition check and installation of a flywheel/drive disk.
*Although after removing the head and sump (without removing the engine) it becomes possible to dismantle the connecting rod and piston assemblies, this opportunity should not be abused due to the difficulties associated with the need to maintain cleanliness and carry out a number of preparatory procedures. In view of the foregoing, a description of this procedure is given in Part General and overhaul of the engine.
Before starting work, thoroughly clean the engine compartment and external surfaces of the power unit using one of a wide range of special solvents. This treatment will prevent dirt from getting inside the engine.
If necessary, depending on the nature of the work ahead, the hood can be removed in order to provide freedom of access to the components to be serviced (see chapter Body), - in order to avoid accidental damage to the paintwork, cover the fenders of the car with special covers, or simply with old blankets.
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