Automotive engines rely on valves to let the fuel-air mixture in and exhaust out, and most modern pushrod and overhead cam engines use lifters to open and close the valves. While the original ...

Overhead-valve internal-combustion ... in which there are OHV-style lifters and rocker arms but the camshaft lives in the cylinder head instead of the block and therefore needs no pushrods to ...

Many gasped when Ford switched its V8 engines in the F-150 to an overhead valve cam (duh!) design, and the debate about whether it produced a better engine is still ongoing. Nevertheless ...