2.3.8. Dismantling, check and assembly of a head of the block of cylinders

Fig. 2.140. Head of the block of cylinders and klapanny mechanism

The head of the block of cylinders is cast from an aluminum alloy, has the pressed pig-iron saddles and directing plugs of valves. The top part of plugs is condensed with rezinometallichesky maslootrazhatelny caps.

As spare parts directing plugs with the increased external diameter are delivered.

In the top part of a head of the block of cylinders support under camshaft necks are located. Support are executed by the demountable. The top half is in cases of bearings, and bottom – in a head of the block of cylinders. Openings in support are processed assembled with cases of bearings therefore they are not interchangeable and it is possible to replace a head of the block of cylinders only assembled with cases.

Valves are put in action by camshaft cams through hydraulic pushers. Adjustment of gaps in the mechanism of a drive of valves with hydraulic pushers is made at operation of the engine automatically.

Fig. 2.141. Order of a reversing of bolts of fastening of a head of the block of cylinders

By means of the special tool (keys for a bolt of fastening of a head of the block of cylinders 09221-32001, 09221-11000) unscrew bolts of fastening of a head of cylinders in an order specified in drawing (fig. 2.141).

Fig. 2.142. Removal of crackers, plates of a spring, a spring and the valve by means of the special adaptation

By means of the special tool (the adaptation for compression of klapanny springs 09222-28000 and an adapter 09222-28100) take crackers from a plate of a spring of the valve. Then remove a plate of a spring of the valve, a valve spring, a saddle of a spring of the valve and the valve (fig. 2.142).

NOTE Store details for each of valves separately a set not to mix them at installation.

Fig. 2.143. Removal of maslosjemny caps

By means of the special tool (a stripper of maslosjemny caps 09222-29000) remove maslosjemny caps (fig. 2.143).

NOTE The reuse of maslosjemny caps of valves is not allowed.

Check a head of the block of cylinders on lack of cracks, damages and traces of leakage of cooling liquid. At detection of cracks replace a head of cylinders.

Completely clear a head of the block of cylinders of a scum, a deposit and the remains of old hermetic and laying. After cleaning of channels for pass of oil blow them the compressed air to remove a possible contamination.

Fig. 2.144. Check of not planeness of a privalochny surface of a head of the block of cylinders

Check not planeness of a privalochny surface of a head of the block of cylinders in the directions shown in drawing fig. 2.144.

If not planeness exceeds maximum permissible value in any direction, or replace a head of cylinders, or slightly grind a privalochny surface of a head of cylinders.

Not planeness of a privalochny surface of a head of cylinders:

– the nominal rate – is less than 0,03 mm;

– maximum permissible value – 0,06 mm.

Fig. 2.145. Valve cleaning

By means of a wire brush carefully clear the valve (fig. 2.145).

Fig. 2.146. Valve check

Check each valve and its core on lack of wear, damages and plate deformation (fig. 2.146).

Replace the valve if necessary. If at an end face of a core of the valve dents were formed or there is a considerable wear, process an end face of a core of the valve. The thickness of a removed layer when machining an end face of a core of the valve should be minimum. Besides, process a working facet of a saddle of the valve.

Replace the valve, if thickness of a plate of the valve less maximum permissible value.

Values of thickness of a plate of the valve are given below.

Nominal rate:

- the inlet valve – 1,15 mm;

- the final valve – 1,35 mm.

Maximum permissible value:

- the inlet valve – 0,80 mm;

- the final valve – 1,00 mm.

Fig. 2.147. Measurement of length of a spring of the valve in

Check length of each spring of the valve in a free condition. If length of a spring less maximum permissible value, replace a valve spring (fig. 2.147).

Fig. 2.148. Check of a deviation of an axis of a spring

By means of a square check a deviation of an axis of each spring from a perpendicular to a basic surface (not perpendicularity) (fig. 2.148).

If not perpendicularity more maximum permissible value, replace a valve spring.

Nominal rate of length of a spring in a free condition: 48,86 mm.

Length of a spring under load of 183 N: 39,00 mm.

Length of a spring under load of 400 N: 30,50 mm.

Axis deviation springs (not perpendicularity): 1,5 ° or it is less.

Maximum permissible value

Length of a spring in a free condition: 47,86 mm.

Axis deviation springs (not perpendicularity): 3 °.

Fig. 2.149. Gap check between the directing plug and a valve core

Check a gap between the directing plug of the valve and a valve core (in several points on length). If a gap more maximum permissible value, replace directing plug of the valve (fig. 2.149).

Values of size of a gap between the directing plug and a core of the valve are given below.

Nominal rate:

- the inlet valve – 0,02–0,05 mm;

- the final valve – 0,035–0,065 mm.

Maximum permissible value:

- the inlet valve – 0,10 mm;

- the final valve – 0,13 mm.

Fig. 2.150. Scheme of restoration of a saddle of the valve

Check a valve saddle on lack of traces of an overheat and non-uniform contact to a working facet of a plate of the valve. At need or restore (mechanically process), or replace a valve saddle. Before restoration of a saddle of the valve check directing plug of the valve on lack of wear. If the directing plug is worn-out, at first replace it, and then restore a valve saddle. Restoration of a saddle of the valve is made by the special tool (mills or on the stanochny equipment). The width of a contact surface of a saddle of the valve should correspond to nominal rates and the spot of contact should be located evenly on the center of a working facet of a plate of the valve. After saddle restoration the valve and a saddle of the valve should be ground in with use of pritirochny paste.

Mechanically process (cut off) a replaced saddle of the valve from within for reduction of thickness of its walls.

Fig. 2.151. The scheme of boring of an opening in a head of the block of cylinders

Chisel an opening in a head of the block of cylinders for installation of a saddle of the valve of the corresponding repair size (the increased diameter) (fig. 2.151).

Heat up a head of cylinders to temperature approximately 250°С and press a new saddle of the repair size in a landing opening of a head of cylinders.

Grind in the valve to a new saddle with use of pritirochny paste.

Width of a contact surface of a saddle of the valve for the inlet channel – 1,1–1,5 mm, for the final channel – 1,3–1,7 mm.

Fig. 2.152. Vypressovka of the old directing plug of the valve

By means of the special tool (an opravka for installation of the directing plug 09221-22000A/in) выпрессуйте the old directing plug of the valve from a head of the block of cylinders in the surface direction under laying (fig. 2.152).

Chisel an opening of a head of the block of cylinders for installation of the directing plug of the valve of the corresponding repair size (the increased diameter).

Fig. 2.153. A difference of values of length of directing plugs for inlet and final valves

By means of the special tool (an opravka for installation of the directing plug 09221-22000A/in) press the new directing plug of the valve from the top surface of a head of cylinders. Pay attention to a difference of values of length of directing plugs for inlet and final valves (fig. 2.153).

NOTE Do not establish directing plug of the valve if it does not correspond to the repair size.

After installation of the directing plug of the valve insert the new valve and check that the gap between the directing plug and a core of the valve corresponds to nominal rate.

After replacement of the directing plug of the valve check correctness of landing of the valve in a saddle. If necessary process a valve saddle.

Put engine oil on all rubbing and rotating details.

Establish saddles of springs of valves.

NOTE Carefully clear all details before assembly.

Fig. 2.154. Installation of a maslosjemny cap

By means of the special tool (an opravka for installation of a maslosjemny cap 09222-22001) easy blow establish a maslosjemny cap into place (fig. 2.154).

NOTE The reuse of maslosjemny caps is not allowed. The wrong installation of a maslosjemny cap can lead to emergence of leakages of oil via directing plug of the valve.

Grease a valve core with engine oil. Insert the valve into directing plug.

Do not apply effort at pass of a core of the valve through a maslosjemny cap. After installation of the valve check smoothness of its moving.

Fig. 2.155. Scheme of installation of a spring of the valve

Establish a valve spring so that the painted round of a spring was located about a plate of a spring (above), and then establish a plate of a spring of the valve (fig. 2.155).

Fig. 2.156. Installation of crackers

By means of the special tool (the adaptation for compression of klapanny springs 09222-28000 and an adapter 09222-28100) compress a spring of the valve and establish crackers. Before removal of the special tool after installation of the valve check reliability of installation of crackers (fig. 2.156).

NOTE At compression of a spring of the valve watch that the plate of a spring did not concern a maslosjemny cap.

Clear the privalochny planes under laying on a head and the block of cylinders.

Check compliance of identification labels of laying of a head of cylinders to specifications.

Establish laying of a head of cylinders on the block of cylinders an identification label up (to a head of cylinders).

Fig. 2.157. Order of a tightening of bolts of fastening of a head of the block of cylinders

Tighten bolts of fastening of a head of the block of cylinders the nominal moment in an order shown in drawing fig. 2.157.

Moment of an inhaling of bolts of fastening of a head of the block of cylinders:

M10-25 N · m + (60–65 °) + (60–65 °);

M12-30 N · m + (60–65 °) + (60–65 °).