Valve Wear Check Points
1. Butt; 2. Grooves for crackers; 3. Rod; 4. Chamfer; 5. Inlet valve; 6. Belt; 7. Exhaust valve
Typical valve face wear
Cleaning
1. Remove any gasket residue from the split surfaces of the head, being careful not to damage the surfaces. Remove carbon deposits from combustion chambers, valve heads and scale from cooling channels. Run and clean all threaded holes.
2. Wash all parts of the valve mechanism with solvent, being careful not to damage them.
Examination
Head
1. Carefully inspect the head for cracks and signs of coolant intrusion. If cracks are found, replace the head.
2. Check the deformation of the split surface of the head. If the deviation from the plane exceeds the norm, then the head should be reground.
3. Check the condition of the valve seats. In the presence of pitting (fossae), cracks, traces of burning, head repair in a car service will be required.
4. Check valve side play (arrow). If half of the total play on the indicator exceeds the norm, then the sleeve should be replaced (carried out in a car service).
Valves
5. Check the valves carefully (see pic. Valve Wear Check Points), check for cracks on the chamfers of the valves, traces of uneven development, metal carryover and burnout. Check for cracks in the necks and stems and for bending of the stems by turning the valve in the guide.
6. Check the wear of the ends of the rods (see fig. Typical valve face wear). The presence of any of these defects indicates the need for valve repair.
7. Measure the width of the edge band (1) each valve and compare with the standard value. If this distance is less than normal, then replace the valve.
Valve train parts
8. Measure the free length of the spring. Replace shrink springs. Before installing the springs on a repaired engine, it is necessary to check them under load on a special stand in a car service.
9. Check the verticality of the springs. If a deviation of the spring from the vertical is detected, the spring should be replaced.
10. Check up presence of visible traces of wear and cracks on plates of springs and crackers. Replace parts with any defects.
11. If during the check it turns out that the wear of the parts does not exceed the norm, then assemble the cylinder head by installing the parts in their original places. Repair of the cylinder head of any complexity should be done in a car service.