Withdrawal
1. Using a special key (09221-32001), loosen the cylinder head bolts.
2. Gradually turn away bolts of a head of the block of cylinders in specified on fig. sequences.
3. Using a special tool (09222-21001), valve spring compressor, remove the cotters.
4. Arrange these parts in such a way that they fit into place during assembly.
5. Using pliers, remove the valve seals.
Note. Do not reuse sealing caps.
Examination
Cylinder head
1. Completely remove scale, sealant and crankcase. After cleaning the oil passages, blow them out with compressed air.
2. Visually inspect the cylinder head for cracks, damage, and coolant leaks.
3. Using a ruler with a sharp edge and a feeler gauge, check the flatness of the bottom surface of the cylinder head, as shown in the figure.
Deviation from the flatness of the cylinder head:
- Rated value - max. 0.05 mm
- Limit value - 0.20 mm
Valve bushings
Check clearance between valve stem and bushing. If the clearance exceeds the allowable value, replace the valve bushing.
Clearance between valve stem and sleeve:
- Rated value:
- Inlet valve - 0.03-0.06 mm
- Exhaust valve - 0.05-0.09 mm
- Limit value:
- Inlet valve - 0.10 mm
- Exhaust valve - 0.15 mm
Valve
1. Replace the valve if its stem is worn (wear or damage). Also replace the valve if the stem end (surface in contact with the automatic lash adjuster) has indentations.
2. Check the contact strip of the valve face and, if necessary, grind it or replace the valve.
3. Replace the valve if the cylinder head size is less than the minimum value.
Size of the cylindrical part of the valve head:
- Rated value:
- Inlet valve - 1.2 mm
- Exhaust Valve - 2.0mm
- Limit value:
- Inlet valve - 0.7 mm
- Exhaust valve - 1.5mm
Valve springs
1. Check the free height of each spring, replace if necessary.
2. Using a square, measure the deviation of each spring from vertical. At a considerable deviation of a spring from verticality replace it.
valve spring:
- Rated value:
- Free height - 50.5 mm
- Force - 32.9 kgf / 40.4 mm
- Deviation from verticality - max. 2°
- Limit values:
- Free height - 49.5 mm
- Force - 32.9 kgf / 41.4 mm
- Deviation from verticality - max. 4°
Valve seat reconditioning
1. Check bushings for wear before rebuilding seats. If necessary, replace worn bushings, then restore the valve seats.
2. After restoring the valve seats, use a valve seat cutter and extension.
3. After reconditioning, the valve and its seats should be lightly lapped using lapping paste.
4. Check valve seats for pitting. If the sinks are oversized, replace the seat with a new one.
5. After installing the lower plate, valve spring, upper plate and crackers, measure the height of the valve spring in the installed position. The measurement results allow the size of the valve seat shells to be determined.
Height A of valve spring in installed position (for intake and exhaust valves):
- Nominal value - 40.4 mm
- Limit value - 41.4 mm
Valve seat replacement
1. Cut off the inside surface of the valve seat to reduce its thickness, then remove the seat.
2. Adjust the diameter of the valve seat hole in the cylinder head to the diameter of the oversized seat for press fit installation.
3. Heat the cylinder head to approximately 250°C and press the oversized seat into the cylinder head bore at normal temperature.
4. Machine the valve seat as shown.
5. Using lapping paste, lap the valve.
Valve seat dimensions
Name | Size, mm | Dimension mark | Height H of the valve seat, mm | The inner diameter of the hole in the cylinder head, mm |
Inlet valve seat | 0,3 O.S.
0,6 O.S. | 30
60 | 7,9-8,1
8,2-8,4 | 44,300-44,325
44,625-44,625 |
Exhaust valve seat | 0,3 O.S.
0,6 O.S. | 30
60 | 7,9-8,1
8,2-8,4 | 38,300-38,325
38,625-38,625 |
Valve seat contact strip width:
- Inlet valve - 0.9-1.3 mm
- Exhaust valve - 0.9-1.3 mm
Valve bushing replacement
1. Using a special tool (09222-32200), press the old valve bushing towards the bottom of the cylinder head.
2. Rotate the valve stem bore to match the press fit of the new oversized bushing.
Valve repair sleeves
Size, mm | Dimension mark | Bore diameter in the cylinder head, mm |
0,05 O.S. | 5 | 13,050-13,068 |
0,25 O.S. | 25 | 13,250-13,268 |
0,50 O.S. | 50 | 13,500-13,518 |
3. Using a special tool (09222-32200), press in the valve bushing. The valve sleeve must be pressed in from the top side of the cylinder head. Be aware that valve stems have different lengths.
4. After pressing the bushings, insert new valves into them and check the clearance.
5. After replacing the valve stems, check that the valve face and seat are in proper contact.
Note. Do not install when changing bushings of the same size.
Installation
1. Install the lower valve springs.
2. Using a special tool (09222-32100) push the sealing caps into place.
Note:
- Do not reuse old sealing caps.
- Incorrect installation of the sealing cap may cause oil to leak down the valve stem.
3. Apply engine oil to each valve. Insert the valves into the sleeves: Do not force the valves into the sealing caps.
4. Valve springs should be installed with the coated side facing the top poppet.
5. Using a special tool (09222- 21001), compress the spring and install the crackers. After installing the valves before releasing the spring of their adaptation, check the correct installation of crackers.
Note. When compressing the spring, make sure that the sealing cap is not pressed against the bottom of the upper spring plate.
6. Clean the bottom surface of the cylinder head and the top surface of the block itself.
7. Check the identification marks on the cylinder head gasket.
8. Position the gasket so that its surface with the identification mark faces the cylinder head.
Note. Do not apply sealant to this surface.
9. Using a special tool (09221-32001) and a torque wrench, tighten the cylinder head bolts in the sequence shown in the figure.
10. When tightening the head bolts, repeat tightening 2 or 3 times in succession, increasing the tightening torque each time, until the required torque is reached.
- Tightening torque: Cylinder head bolts Cold engine (engine coolant temperature about 20°C) - 105-115 Nm.