Question

Technician A says that a camshaft must open and close each valve at exactly the right time relative to piston position. Technician B says overhead cam engines can be belt-driven. Who is correct?

Answer 1

On single and double overhead cam engines, the cams are driven by the crankshaft, via either a belt or chain called the timing belt or timing chain. These belts and chains need to be replaced or adjusted at regular intervals.