What does 'OHV' stand for in engine terminology?

“What does ‘OHV’ stand for in engine terminology?” — OHV means overhead valve.

In an overhead-valve engine, the intake and exhaust valves sit in the cylinder head above the combustion chamber. The camshaft is usually mounted in the engine block, and pushrods plus rocker arms transfer its motion to the valves. This layout is why OHV engines are also commonly called pushrod engines.

OHV is often confused with OHC, or overhead camshaft. Both designs place the valves above the combustion chamber, but an OHC engine places its camshaft in the cylinder head. OHV engines can be compact and mechanically durable, especially in V-shaped engines, although their extra valvetrain parts can limit high-rpm performance.

The design dates to the early development of internal-combustion engines. Rudolf Diesel’s 1894 prototype used overhead poppet valves operated by a camshaft, pushrods, and rocker arms. Buick introduced one of the first production OHV cars, the 1904 Model B.