Technician A measures valve lash on an OHC engine by rotating the engine to TDC for number 1 cylinder then measures the gap between the cam and tappet for all the valves. Technician B sets the engine at TDC for number 1 cylinder then measures the gap between the cam and tappet only on the valves that are closed. He then rotates the crankshaft 360 degrees and measures the gap between cam and tappet for the remaining valves. Who is correct?
A)A only
B)B only
C)both A and B
D)neither A nor B

Question

Quizplus · Accepted Answer

Technician B is correct because valve lash should be measured when the valves are closed, which requires rotating the engine to ensure each valve is in the correct position. Technician A's method is incorrect as it does not ensure all valves are closed when measuring.

Technician a Measures Valve Lash on an OHC Engine by Rotating