Question

The least coefficient of thermal expansion to avoid excessive thermal stress is experienced by which part of the valve?

(a) Head

(b) Face

(c) Stem

(d) Margin

This question was posed to me by my school teacher while I was bunking the class.

Enquiry is from Poppet Valves topic in section Valve Timing Technologies of Automotive Engine Design

Answer 1

Right option is (a) Head

The explanation is: The Least coefficient of thermal expansion to avoid excessive thermal stress is experienced by the head part of the valve because it experiences the heat from the combustion directly.