Skip to main content
Camshaft with pushrods- Rocker arm Valve Piston Connectingrod Crankshaft sprocket Drive chain Camshaftsprocket Cam Tappet Pushrod

When the camshaft is mounted in the engine block, long pushrods operate the rocker arms which in turn open the valves. This overhead-valve (OHV) system is less efficient than an overhead camshaft because the number of moving parts limits the speed at which the engine can run safely.

Articles Title

The engine - how the valves open and close

Engine with overhead camshaft An overhead-cam (OHC) engine needs fewer parts to operate the valv...