Question

What is the clearance between rocker arm and valve stem is known as _______

(a) Valve clearance

(b) Sleeve

(c) Tappet clearance

(d) Buffer space

This question was posed to me during an interview.

My question is from Diesel Engine Vs. Petrol Engine in division Internal Combustion Engine of Farm Machinery

Answer 1

The correct choice is (c) Tappet clearance

To explain I would say: Tappet clearance is the clearance between the rocker arms and the point where they rest on the valves. Usually both the surface are flat surfaces. In four-stroke engines, rockers arms arrangement opens and closes the inlet and outlet valves.