Word forms: (regular plural) overhead valves
( Automotive engineering : Vehicle components , Engine, transmission, and exhaust ) valve
An overhead valve
is a valve in the cylinder head of an engine.
He pressed the button on the starter motor and the overhead valve unit burst into life.
Modern racing cars are built with an overhead cam engine rather than an overhead valve engine.
Overhead valve engines have the valves located above the combustion chamber, in the cylinder head.
Collins English Dictionary. Copyright © HarperCollins Publishers