3.2. Petrol engine in volume 2,0 liters
In this part of the management types of works on repair of engines with volume of 2,0 l which are carried out directly on the car are described. If the engine acted in film from the car and understood, all preliminary operations on dismantling are excluded.
It should be noted that despite real possibility of major maintenance without removal of the engine of such knots as shatunno-piston group, this type of works usually it is impossible to execute as some independent operation. For repair krivoshipno-shatunny and other mechanisms as a rule it is necessary to execute some additional actions (obligatory cleaning of details and washing of oil channels, for example, is). For this reason such works are included in the list of the main procedures of major maintenance of the engine.
The engine of 2,0 l (1998 cm/cubes) belongs to the SR series, established on Nissan cars.
The engine 16-klapanny, with the top arrangement of the valves, four rowed cylinders and two cam-shafts. The engine settles down across a car axis, in its forward part. Transmission is established on the left side of the engine.
Crankshaft 5-basic. Axial люфт the crankshaft it is regulated by selection of the persistent half rings established near the top loose leaf of the average (3rd) radical bearing.
Shatunnye bearings consist of two loose leaves inserted into a rod and in a cover of a rod parallel to an axis of the crankshaft. Rods are connected to pistons by means of fingers which are established with a tightness in a head of a rod and fixed in the piston by spring lock rings. Pistons are cast from an aluminum alloy, on pistons three rings – two kompressionny and one maslosjemny are provided.
The block of cylinders is cast from cast iron, in the block cylinders are chiseled. On engines of considered type of an opening of cylinders sometimes are called as "dry sleeves".
Inlet and final valves are closed under the influence of spiral springs and move in the directing plugs pressed in a head of the block of cylinders together with saddles of valves. At the increased wear of a saddle and the plug it is possible выпрессовать independently from each other and to replace new.
Cam-shafts have a drive from a chain and operate 16 valves via levers. Levers are established directly under cam-shafts. Gaps in valves are regulated automatically by means of hydraulic devices. The bottom support of necks of cam-shafts are the beds chiseled in inflow of a head of cylinders.
The oil pump is intended for greasing of the engine with a drive from a crankshaft sock. Oil passes through a maslopriyemnik with the filter of rough cleaning and through the filter of thin cleaning screwed in the block of cylinders from which via lubricant channels in the block of cylinders and a case of the crankshaft goes to radical bearings of the crankshaft and to basic necks of a cam-shaft. Bearings are greased with Shatunnye under pressure through openings in the crankshaft, under pressure also basic necks of a cam-shaft also are greased. Cam-shaft cams, cores of valves and other details of the engine are greased with a razbryzgivaniye. On some models the maslookhladitel intended for maintenance of temperature of oil at constant level in extreme operating conditions of the engine is provided.