Valves, Grind
Valves can be reused once or twice after regrinding if there are no crater-like burns on the valve cone. Further regrinding cannot be recommended, as then the upper valve head edge becomes too thin and can become burnt very quickly, especially the exhaust valves.
The valve stem must not protrude further than dimension "I" from the cylinder head. Measure projection with KM-419. Do not regrind valve stem ends.
During all machining operations on valves, it must be ensured that the angle at the valve head is 92 ° , at the valve seat 90 ° . See also Technical Data.
This achieves a rapid slamming shut and unavoidable operating tolerances are compensated. Always adjust support for valve grinder to 92 ° .