 printable version
Cylinder Head
Removal and dismantling
| Fig. 2.33. Cylinder head: 1 - the cylinder head bolts, 63 Nm + weaken all bolts 20 Nm + to tighten on a corner 90 ?� + to tighten on a corner 90 ?�; 2 - washer; 3 - crackers; 4 - spring plate; 5 - the valve stem seal; 6 - a spring; 7 - spring seat; 8 - the directing plug of the exhaust valve; 9 - an inlet valve seat; 10 - inlet valve; 11 - the block of cylinders; 12 - cylinder head gasket; 13 - exhaust valve; 14 - the seat of the exhaust valve; 15 - cylinder head; 16 - the directing plug of the intake valve
|
Elements of the cylinder head shown in Fig. 2.33.
| Fig. 2.34. The sequence reversing of bolts of the cylinder head
|
Special tools 0921-32001 in the sequence shown in Fig. 2.34, unscrew the bolts of the cylinder head.
| Fig. 2.35. Using special tools to compress the valve spring
|
Special tools (09222- 28000, 09222-28100) compress valve spring and remove crackers (Fig. 2.35). Then remove the plate springs, valve spring, spring seat and the valve. Pliers, remove the valve stem seal.
Check Cylinder Head Check the cylinder head for cracks, damage and leakage of coolant. If there is a crack, replace the cylinder head. Completely remove scale, sealant, and carbon deposits. After cleaning, lubricating channels blow them with compressed air.
| Fig. 2.36. Directions flatness measurement mating surface of the cylinder head
|
Metal ruler and probe in the directions shown in Fig. 2.36, check the flatness of the mating surface of the cylinder head. If permissible flatness exceeded in either direction, replace or pereshlifuyte head. Rated flatness of less than 0.03 mm, the maximum permissible deviation - 0.2 mm. Valves Wire brush, clean the valve well. Inspect each valve for wear, damage, deformation and plate stock, if necessary, repair or replace it. If the end of the stem is worn or eaten, as appropriate, restore the chamfer. This recovery should be limited to the minimum metal removal. Check the width of the working facets. Replace the valve if the operating chamfer worn to the minimum limit. Nominal thickness of the bevel, mm: intake valves ..... 1.0 exhaust valves ..... 1.5 Maximum allowable edge thickness, mm: intake valves ..... 0.7 exhaust valves ..... 1.0 Valve springs Measure the length of each spring in a free state. If the spring length is not correct, replace it. Install the spring on a flat horizontal surface and square measure the deflection of the spring from the top of the vertical plane. The length of the spring in a free state - 45.82 mm, under a load of 25.3 kg -40 mm. The maximum permissible length of the spring in the free state - 44.82 mm. The deviation from the vertical plane of the spring - not more than 1.5 ?�. Maximum permissible deviation of a spring from a vertical plane - no more than 4 ?�. Valve guides Check the clearance between the stem and the valve guide. If the backlash exceeds maximum permissible, replace the valve guide to the bushing larger size. The nominal gap between the stem and the valve guide, mm: intake valves ..... 0,02-0,047 exhaust valves ..... 0,05-0,085 Maximum permissible backlash between the stem and the valve guide, mm: intake valves ..... 0.1 exhaust valves ..... 0.15
Repair the valve seat Check valve seat for the presence of heat and uniform contact with the working surface of the valve. If necessary, repair or replace the valve seat. Before repairing the valve seat, check the valve guide wear. If the valve guide sleeve is worn, replace it, and then repair the saddle. Repair the valve seat is held emery wheel or cutter. Width of a working facet of the valve seat must be within the limits specified in the technical data, and centered with a working surface of the valve. After repairing the valve and the valve seat is necessary to grind using lapping compound.
Replacing the valve seat
| Fig. 2.37. Cutting area of the old wall and the seat insert bore sizes nest saddle: a - zone of cutting; b - a new hole; with - the old port; D - diameter of the saddle
|
Any valve seat, which developed the service life can be removed after cutting most of its walls with a special tool (Fig. 2.37). After removing the saddle scan or treat it with a chisel a hole to the values shown in Table. 2.5.
Table 2.5 Allowances for the installation of the valve seat
Heat the cylinder head to a temperature of 250 ?� C and the press in her seat in an enlarged size, the saddle should be normal (room) temperature. Lapping, lap the valve to the new seat. The width of the contact of the valve seat - 0.9-1.3 mm.
Replacing the valve guide
| Fig. 2.38. Using special tools 09222- 21200 09222- 21200 A and B for pulling out the guide (1) of the valve head (2) Cylinder
|
The special tool 09222-21200 A press and squeeze out the valve guide toward the cylinder block (Fig. 2.38). Deal with the hole in the cylinder head for the new valve guide to the size of the new valve guide with a larger size. The size of the holes in the cylinder head must be less than the nominal and conform to the values given in the Table. 2.6.
Table 2.6 Repair size valve guide
Using the special tool 09222-21200 A and 09222-21200 B, press-fit the valve guide. Valve guide should be pressed from the upper side of the cylinder head. Remember that guides the intake and exhaust valves are different in length (46 mm - 54.5 mm, and the inlet - outlet).
A WARNING Press-fit the valve guide only oversized. |
After pressing in valve guides, insert new valves and check the clearance between the valve stem and the guide sleeve. When replacing the valve guides, check and, if necessary, replace the valve seat.
Assembly and installation of the cylinder head Install the saddle springs.
| Fig. 2.39. Using the device 09222- 22001 (1) to install the valve stem seal (2) onto the valve seat (3) of the valve spring
|
Special tools (09222- 22001) install the valve stem seal (Fig. 2.39).
A WARNING Before installation, carefully wipe every detail. On the surface of revolution and slip apply engine oil. |
A WARNING Do not reuse an old valve stem seals. Improper installation of the valve stem seal can lead to oil leakage through the valve guide. |
Apply a thin coat of engine oil to the stem of each valve. Insert the valves in the valve guides. Do not use force when entering the valve in the valve stem seal. After installation, check the smooth movement of the valve.
| Fig. 2.40. Location valve spring: 1 - spring retainer; 2 - the valve stem seal; 3 - spring seat; 4 - valve spring; 5 - spring coils, enameled
|
Install the valve spring so that the side coated with enamel, was sent to the plate spring (Fig. 2.40). The special adaptation compress the valve spring and establish crackers (see. Fig. 2.35). Check the location of the crumbs in the upper bracket of the spring, slowly unclench and remove the adaptation for spring compression.
A WARNING When the spring is compressed, make sure that the valve stem seal has not been pinned to the ground crackers. |
Clean both mating surface of the cylinder block and cylinder head. Check the identification label on the cylinder head gasket. Install the new cylinder head gasket so that the surface with an identification mark has been directed to the head unit.
A WARNING Measure the length of each bolt cylinder head. The maximum allowable length of 99.4 mm |
.
Establish a head on the cylinder block.
| Fig. 2.41. The sequence of the bolts fastening the cylinder head
|
Screw the bolts of the cylinder head in the order shown in Fig. 2.41. Tighten bolts in several stages: - New bolts - 63 Nm + weaken all bolts 20 Nm + to tighten on a corner 90 ?� + to tighten on a corner 90 ?�; - Previously used bolts - 20 Nm + to tighten on a corner 90 ?� + to tighten on a corner 90 ?�.
| 
