with typical OHV engines. The exhaust valve(s) were driven by a camshaft, but were located in the engine block as with side-valve engines.

The 1894 prototype Diesel engine used overhead poppet valves actuated by a camshaft, pushrods and rocker arms, therefore becoming the first OHV engines. In 1896, U.S. patent 563,140 was taken out by William F. Davis for an OHV engine with liquid coolant used