VALVES AND VALVE SPRINGS ENG

2.Lap:

●Valve face

●Valve seat

NOTE:

After refacing the valve seat or replacing the valve and valve guide, the valve seat and valve face should be lapped.

Lapping steps:

●Apply a coarse lapping compound to the valve face.

CAUTION:

Do not let the compound enter the gap between the valve stem and the guide.

●Apply molybdenum disulfide oil to the valve stem.

●Install the valve into the cylinder head.

●Turn the valve until the valve face and valve seat are evenly polished, then clean off all of the compound.

NOTE:

For best lapping results, lightly tap the valve seat while rotating the valve back and forth between your hands.

●Apply a fine lapping compound to the valve face and repeat the above steps.

NOTE:

After every lapping operation be sure to clean off all of the compound from the valve face and valve seat.

●Apply Mechanic’s blueing dye (Dykem) to the valve face.

●Install the valve into the cylinder head.

●Press the valve through the valve guide and onto the valve seat to make a clear pattern.

●Measure the valve seat width again. If the valve seat width is out of specification, reface and relap the valve seat.

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