Valve Seat: Testing and Inspection
CONTACT WIDTH1. Produce a contact pattern on each valve by the following procedure:
- Give a uniform coat of a smooth coloring compound to the valve seat. There are many compounds available for this purpose. The manufacturer's instructions should be carefully followed to get proper results.
- Using a valve lapper, produce a contact pattern on each valve by rotating while tapping each valve head to the valve seat.
2. The pattern produced on seating face of each valve must be a continuous ring without any break and width of the pattern must be within 1.3 to 1.5 mm (0.0512 to 0.0590 inch) for both intake and exhaust valves.