Lapping valves (Mazda Familia BG)

1. Even perfectly machined valve seats and new valves must be lapped together to ensure optimum sealing. This is especially important in diesel engines.



2. Valves can be lapped only with fine-grained grinding paste. A suction cup is installed on the valve plate for rotation. The formation of grooves during lapping can be avoided by frequently removing and rotating the valve further.

Caution! After lapping, the grinding paste must be completely removed.

3. The lapping process is controlled by applying to the contact surface "Preussischblau" or "Bleiweiss", and also with fuel. Insert the valves, fill the combustion chamber with fuel, fuel should not flow out to the valve guide. Otherwise, the grinding process should be repeated.

Text taken from an online platform (mazbook.ru)