Technician A says that it is normal for the piston to remain stationary at TDC for a few degrees of crankshaft rotation. Technician B says that if the intake valve is open more at TDC than the exhaust valve, the cam is retarded. Who is right?
A)Technician A only
B)Technician B only
C)Both A and B
D)Neither A nor B

Question

Quizplus · Accepted Answer

Technician A is correct because during the four-stroke cycle, the piston does indeed pause momentarily at Top Dead Center (TDC) due to the crankshaft and connecting rod mechanics. This is a normal part of the engine's operation. Technician B is incorrect because the relative opening of the intake and exhaust valves at TDC does not directly indicate cam timing (advanced or retarded); it depends on the camshaft design and the engine's valve timing setup.

Technician a Says That It Is Normal for the Piston