1999-2003 of release
Repair and operation of the car
Subaru of Legasi, Autbek
+ Cars Subaru Legacy, Outback
+ Operation manual
+ Routine maintenance
Check of compression pressure in cylinders and tightness of the block
Diagnostics of a condition of the engine with use of the vacuum gage
The engine lubrication system - the general information
+ the repair Procedures which are not connected with extraction of the engine from the car - four-cylinder engines
+ the repair Procedures which are not connected with extraction of the engine from the car - six-cylinder engines
+ General and capital repairs of engines
+ Cooling systems, heating
+ Power supply system and release
+ Electric equipment of the engine
+ Manual box and differential
+ Automatic transmission
+ Brake system
+ Suspension bracket and steering
+ Onboard electric equipment
General informationScheme of an arrangement of the main components of the 4-cylinder opposite SOHC engine
Design of a head of cylinders of the 4-cylinder opposite SOHC engine
Design of camshafts of the 4-cylinder opposite SOHC engine
Design of components of a head of cylinders of the 6-cylinder opposite DOHC engine
Design of camshafts of the 6-cylinder opposite DOHC engine
In this Chapter the device and procedures of service of engines of two types is described: with one (SOHC) or two (DOHC) camshafts of the top arrangement for each of heads of cylinders.
4-cylinder engines 2.0 and 2.5 of l
On models 2.0 and 2.5 of l 4-cylinder opposite petrol engines which are horizontally installed in forward part of the car are installed. These 4-stroke engines with liquid cooling and one (on a head) a camshaft of the top arrangement (SOHC) are supplied with the 16-valvate mechanism of gas distribution and made mainly of an aluminum alloy. Fuel moves in the engine by method of the distributed injection (MFIS).
Block of cylinders
The block of cylinders is made of an aluminum alloy by a molding method under pressure and supplied with the pig-iron sleeves of cylinders of dry type which are filled in in unit semi-blocks.
The structure of the cast block of cylinders allows to provide effective heat removal and gives it high durability with rather small weight.
The cranked shaft is established in five radical bearings of the increased durability the fifth of which is persistent and limits the size of an axial side play of a shaft.
Installation sites of radical bearings of a cranked shaft are developed in such a way that sufficient rigidity at a minimum level of a working noise background is provided.
The oil pump is located on the center in forward part of the block of cylinders, the water pump of the cooling system – in forward part of the left semi-block. In back part of the right semi-block the oil separator catching the oil suspension containing in karterny gases is established.
Heads of cylinders
Heads of cylinders are made of an aluminum alloy by a molding method under pressure.
The head of cylinders forms combustion chambers of tent type with the central arrangement of spark plugs and four valves (two inlet and two final) on the cylinder. Inlet and final valves are located on the different parties of the cylinder.
The central placement of spark plugs in combustion chambers promotes the distribution of turbulences increasing efficiency of combustion of air and fuel mix.
At the expense of an opposite arrangement of inlet and final valves the cross and line scheme of gas distribution is realized.
Metal laying of a head of cylinders is created from steel corrosion-proof sheets and has the three-layer design differing in the increased heat resistance and the providing reliability of sealing of a joint of the interfaced surfaces for a long time.
The drive of camshafts of the left and right heads of cylinders is carried out by means of one gear belt which is also used for the drive of the water pump located in the left semi-block of the power unit. Adjustment of a tension of a gas-distributing belt is made by the automatic regulator of a tension that excludes need of manual adjustments.
The camshaft keeps in a head of cylinders on four necks.
Two persistent flanges limit the size of an axial side play of each of camshafts.
The maslotok providing supply of greasing and cooling of the GRM components are provided in axial part of shaft.
In yokes of the drive of valves the screw and a nut intended for correction of valvate gaps are built in.
6-cylinder engines of 3.0 l
Models of 3.0 l are equipped with the 6-cylinder petrol engine of an opposite design which is horizontally installed in forward part of the car. These 4-stroke engines with liquid cooling and two (on a head) camshafts of the top arrangement (DOHC) are supplied with the 24-valvate mechanism of gas distribution and made mainly of an aluminum alloy. Fuel, as well as on 4-cylinder engines, moves by method of the distributed injection (MFIS).
Level of the vibrations made by opposite 6-cylinder engines, considerably below than at engines of a V-shaped design (V6). Besides, the similar design at high compactness allows to organize good dynamic balancing. Decrease in the noise background arising during the operation of the engine is helped by also following constructive decisions:
· The cranked shaft is established in seven radical bearings of the increased durability and has diameter of 64.0 mm that is 4 mm more, than on the previous models;
· Chains of the GRM drive are equipped with the hydraulic regulator of a tension and closed by a cover;
· The pallet of a case made of an aluminum alloy increases rigidity of a joint of the left and right semi-blocks, giving thereby additional durability to the zones forming beds of radical bearings of a cranked shaft;
· The engine is connected to transmission by more rigid 11-bolted connection in comparison with 8-bolted connection used in the previous models.
Use of the chain drive of camshafts which is not needing service allowed to reduce the full length of the power unit.
One more distinctive feature of 6-cylinder opposite engines used on the Subaru Legacy models is the low level of the content in the fulfilled gases of toxic components.
Block of cylinders
Each of semi-blocks is equipped with the independent cooling contour. Water shirts round sleeves of cylinders are open from heads (the open scheme) that considerably increases efficiency of cooling of components.
The special form of the top part of the pallet of the case made of an aluminum alloy promotes suppression of considerable fluctuations of level of oil and, besides, forms part of contours of greasing and cooling, and also spiral chamber of the water pump and the camera of the thermostat.
Heads of cylinders