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

Device

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



The head of the block of cylinders is cast from aluminum alloy, has the pressed pig-iron saddles and the directing plugs of valves. The top part of plugs is condensed with rubber-metal maslootrazhatelny caps.
As spare parts the directing plugs with the increased outer 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 demountable. The top half is in cases of bearings, and lower – in a head of the block of cylinders. Openings in support are processed assembled with cases of bearings therefore they are not interchanged and the head of the block of cylinders can be replaced only assembled with cases.
Valves are put in action by camshaft cams through hydraulic pushers. Adjustment of gaps in the mechanism of the drive of valves with hydraulic pushers is made during the operation of the engine automatically.

Dismantling

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) turn off bolts of fastening of a head of cylinders in the order specified in the drawing (fig. 2.141).

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


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

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

Fig. 2.143. Removal of oil scraper caps


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

NOTE
Reuse of oil scraper caps of valves is not allowed.

Check of a head of the block of cylinders
Check a head of the block of cylinders for lack of cracks, damages and traces of leak 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 sealant and laying. After cleaning of channels for pass of oil blow them 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 the drawing of fig. 2.144.
If not planeness exceeds maximum permissible value in any direction, then 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.

Details of the valvate mechanism

Fig. 2.145. Cleaning of the valve


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

Fig. 2.146. Valve check


Check each valve and its core for lack of wear, damages and deformation of a plate (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 a valve core end face. Thickness of the removed layer when machining an end face of a core of the valve has to be minimum. Besides, process a working facet of a saddle of the valve.
Replace the valve if the plate thickness of the valve is less than 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.

Springs of valves

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


Check length of each spring of the valve in a free state. If length of a spring is less than maximum permissible value, replace a spring of the valve (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 is more than maximum permissible value, replace a valve spring.

Valve spring
Nominal rate of length of a spring in a free state: 48,86 mm.
Spring length under load of 183 N: 39,00 mm.
Spring length under load of 400 N: 30,50 mm.
Deviation of an axis of a spring (not perpendicularity): 1,5 ° or it is less.
Maximum permissible value
Spring length in a free state: 47,86 mm.
Deviation of an axis of a spring (not perpendicularity): 3 °.

The directing plugs of valves

Fig. 2.149. Check of a gap between the directing plug and a core of the valve


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

Restoration of a saddle of the valve

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



Check a valve saddle for lack of traces of an overheat and uneven contact with a working facet of a plate of the valve. If necessary or restore (mechanically process), or replace a valve saddle. Before restoration of a saddle of the valve check the directing valve plug for 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 machine equipment). Width of a contact surface of a saddle of the valve has to correspond to nominal rates and the spot of contact has to be located evenly on the center of a working facet of a plate of the valve. After restoration of a saddle the valve and a saddle of the valve should be ground in with use of pritirochny paste.

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

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 a head of cylinders to temperature about 250 °C 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.

Replacement of the directing valve plug

Fig. 2.152. Vypressovka of an old guide of the plug of the valve


By means of the special tool (a mandrel for installation of the directing plug 09221-22000A/B) a vypressuyta the old directing valve plug from a head of the block of cylinders in the direction of a surface 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 the directing plugs for inlet and final valves


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

NOTE
Do not install the directing valve plug 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.

Assembly
Apply 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 an oil scraper cap


By means of the special tool (a mandrel for installation of an oil scraper cap 09222-22001) establish by easy blow an oil scraper cap to the place of (fig. 2.154).

NOTE
Reuse of oil scraper caps is not allowed.
The wrong installation of an oil scraper cap can lead to emergence of leak of oil via the directing valve plug.

Oil a valve core engine. Insert the valve into the directing plug.
Do not apply effort at pass of a core of the valve through an oil scraper cap. After installation of the valve check smoothness of its movement.

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 install a plate of a spring of the valve (fig. 2.155).

Fig. 2.156. Installation of crackers


By means of the special tool (the device for compression of valvate springs 09222-28000 and an adapter 09222-28100) squeeze 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 you watch that the plate of a spring did not concern an oil scraper cap.

Clear the privalochny planes under laying on a head and the block of cylinders.
Check compliance of identification tags of laying of a head of cylinders to specifications.
Install laying of a head of cylinders on the block of cylinders by an identification tag up (to a head of cylinders).

Fig. 2.157. Order of 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 the order shown in the drawing of fig. 2.157.
Moment of an inhaling of bolts of fastening of a head of the block of cylinders:
M10-25 of N · m + (60–65 °) + (60–65 °);
M12-30 of N · m + (60–65 °) + (60–65 °).