What is the reason that OEMs specify greater valve lash for exhaust valves?
A) they run hotter and expand more
B) they run cooler and contract less
C) they are shorter than intake valves
D) they are longer than intake valves

Question

Quizplus · Accepted Answer

Exhaust valves run hotter than intake valves due to their direct exposure to the hot exhaust gases. This increased temperature causes the metal of the exhaust valves to expand more than the intake valves. To accommodate this expansion and prevent the valves from remaining slightly open when they should be closed (which would lead to loss of engine power and potential damage), OEMs specify greater valve lash (clearance) for exhaust valves.

What Is the Reason That OEMs Specify Greater Valve Lash