Lapping of valves

Even with perfectly machined seats and new valves, they must rub against each other to ensure optimal sealing. This is especially important for a diesel engine.



Valves may only be lapped using fine-grained grinding paste. To perform the necessary rotational movements, a tool with a rubber suction cup is installed on the valve head. The formation of scratches on the landing chamfers during lapping is eliminated by frequent lifting and uniform rotation of the valve.

Attention. Grinding paste must be carefully removed after lapping.

The appearance of the working surface during the lapping process can be controlled using Preupischblau or Bleiweiβ, as well as using fuel. Loosely insert the valve into the guide, fill the combustion chamber with fuel, fuel must not flow to the valve guide. Otherwise, repeat the lapping process.