3.2. The petrol engine in volume of 2,0 litres
In this part of a management kinds of works on repair of engines with volume 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 is necessary to notice that despite real possibility of major repairs without removal of the engine of such knots as shatunno-piston group, this kind of works usually it is impossible to execute as some independent operation. For repair krivoshipno-shatunnogo and other mechanisms as a rule it is necessary to execute some additional actions (obligatory clearing of details and washing of oil channels, for example, is). For this reason such works are included in the list of the basic procedures of major repairs of the engine.
The engine description
The engine of 2,0 l (1998 sm/cube) concerns series SR, established on cars Nissan.
The engine 16-klapannyj, 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.
Коленвал 5-basic. Axial люфт коленвала it is regulated by selection of the persistent half rings established near to the top loose leaf of average (3rd) radical bearing.
Shatunnye bearings consist of two loose leaves inserted into a rod and in a cover of a rod in parallel of an axis коленвала. 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 aluminium alloy, on pistons is provided three rings – two компрессионных and one маслосъемное.
The block of cylinders is cast from pig-iron, in the block cylinders are chiseled. On engines of considered type of an aperture of cylinders sometimes are called as "dry sleeves".
Inlet and final valves are closed under the influence of spiral springs and move in directing plugs, запрессованных to a head of the block of cylinders together with saddles of valves. At the raised deterioration 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 through levers. Levers are established directly under cam-shafts. Backlashes 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 engine greasing with a drive from a sock коленвала. Oil passes through маслоприемник with the filter of rough clearing and through the filter of thin clearing screwed in the block of cylinders from which through lubricant channels in the block of cylinders and картера коленвала goes to radical bearings коленвала and to basic necks of a cam-shaft. Shatunnye bearings are greased under pressure through apertures inside коленвала, 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 разбрызгиванием. On some models it is provided маслоохладитель, intended for maintenance of temperature of oil at constant level in extreme working conditions of the engine.