3.2. 2,0 liters petrol engine
In this part of the management types of the works on repair of engines with volume of 2,0 l performed directly on the car are described. If the engine was removed from the car and understood, then all preliminary operations on dismantling are excluded.
It should be noted that despite a real possibility of capital repairs without removal of the engine of such knots as conrod and piston group, this type of works usually cannot be executed as some independent operation. For repair krivoshipno-conrod and other mechanisms as a rule it is necessary to execute some additional actions (for example, cleaning of details and washing of oil channels is obligatory). For this reason such works are included in the list of the main procedures of capital repairs of the engine.
Description of the engine
The engine of 2,0 l (1998 cm / a cube) belongs to the SR series, installed on the Nissan cars.
The engine is 16-valvate, with the top arrangement of 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.
The crankshaft is 5-basic. The axial side play of the crankshaft is regulated by selection of the persistent half rings established near the top insert of the average (3rd) radical bearing.
Conrod bearings consist of two inserts inserted into a rod and into a rod cover parallel to a crankshaft axis. 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 aluminum alloy, on pistons three rings – two compression and one oil scraper are provided.
The block of cylinders is cast from cast iron, in the block cylinders are chiseled. On engines of the considered type of an opening of cylinders sometimes are called "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 to vypressovat independently from each other and to replace new.
Cam-shafts have the drive from a chain and operate 16 valves via levers. Levers are installed directly under cam-shafts. Gaps in valves are regulated automatically by means of hydraulic devices. The lower support of necks of cam-shafts are the beds chiseled in inflows of a head of cylinders.
The oil pump with the drive from a crankshaft sock is intended for lubricant of the engine. Oil passes through an oil receiver 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. Conrod bearings are greased under pressure through openings in the crankshaft, under pressure also basic necks of a cam-shaft are greased. Cam-shaft cams, cores of valves and other details of the engine are greased with spraying. On some models the oil cooler intended for maintenance of temperature of oil at the constant level in extreme operating conditions of the engine is provided.