Question

Practically, Valve overlap at what range at TDC?

(a) 10°-30°

(b) 40°-75°

(c) 20°-60°

(d) 80°-150°

I had been asked this question in an online interview.

This key question is from Valve Timing in section Valve Timing Technologies of Automotive Engine Design

Answer 1

The correct choice is (c) 20°-60°

For explanation: Practically, Valve overlap at  20°-60° range at TDC and Valve overlap at  80°-150° range at BDC. Valve overlap is the time during which both the inlet and exhaust valves remain open at the same time.