3.1. Petrol engines
This section describes repair operations which can be executed on the engine installed in the car. If repair of already removed engine is made, operations of dismounting can be ignored.
DESCRIPTION OF THE XU ENGINE
The engine with four cylinders installed cross in a forward part of the car. Coupling and the transmission are located on the left side of the engine.
The crankshaft leans on five main bearings. Persistent half rings are established on the second radical bearing.
In the lower heads of a rod inserts are established. Pistons fasten to rods piston fingers. On the engine 2.0 liters piston fingers are established on the sliding landing in rods and fixed by lock rings. On all other models – motionless landing in a rod. Pistons consist of aluminum alloy and have three piston rings, two sealing and one oil scraper.
On aluminum blocks of cylinders of the engine the block of cylinders has the "damp insert" type. Replaceable sleeves of cylinders are established from above the block of cylinders, and consolidation is made in the sleeve basis by a sealing ring of round section.
On engines with the pig-iron block of cylinders the engine has the usual type "dry insert". Cylinders are executed directly in material of the block of cylinders and can only be chiseled at repair of the engine.
On all models the cam-shaft puts a gear belt of the drive in action and operates eight valves (model of 1.6 liters) or sixteen valves (liter models 1.8 and 2.0) through the pushers located under camshaft cams. On models of 1.6 liters valvate gaps are regulated by laying which is established between pushers and the top end face of a core of the valve; on all other models the valvate gaps self-regulating at the expense of hydraulic pushers. The cam-shaft is located in covers of bearings which fasten bolts to the top part of a head of the block of cylinders. Closing of valves is made by springs which press a plate of the valve to a saddle. Saddles and guides of the valve can be replaced.
The pump of the cooling system puts a gear belt of the drive in action and is located on the right side of the block of cylinders.
Lubricant of the engine is produced under pressure created by the oil pump which is given (through a chain and an asterisk) from the right end of the crankshaft. Oil is sucked in via the mesh filter located in an oil receiver and then comes via externally installed filter to canals of the block of cylinders. From there oil arrives to the crankshaft (radical bearings) and a cam-shaft. Bearings of the lower head of a rod are supplied with oil through internal drillings in the crankshaft; to cam-shaft bearings oil also moves under pressure. Cams of a cam-shaft and valves are oiled sprayed, also as well as all other mobile details of the engine.
The oil heater is installed on some models to maintain constant oil temperature under big operational loadings. The oil heater is installed behind an oil filter and is cooled with cooling liquid from the engine cooling system.
Engines are identified not only their working volume, but also and an engine code. The code of the engine consists of three letters (for example: BFZ). The code is beaten out on the plate attached to the forward left side of the block of cylinders or beaten out directly on the forward party of the block of cylinders, to the left of an oil filter.
Repair operations which can be carried out on the engine installed in the car:
– check compression pressure;
– removal and installation of a cover of a head of the block of cylinders;
– removal and installation of a pulley of a bent shaft;
– removal and installation of a casing of a gear belt of the drive;
– removal and installation and adjustment of a tension of a gear belt;
– removal and installation mechanism of a tension of a gear belt;
– replacement of elements of the lubrication system of a cam-shaft;
– replacement of a cam-shaft and pushers;
– check and regulation of valvate gaps;
– removal and installation of a head of the block of cylinders;
– cleaning of a head of the block of cylinders and pistons;
– removal and installation of the oil pallet;
– removal, check and installation of the oil pump;
– replacement of oil consolidations of the crankshaft;
– removal and installation of the transmission;
– removal, survey and installation of a flywheel;
– removal and installation of the oil heater.