THE BEECHMONT CREST AUTOMOTIVE LEARNING ZONE
Camshaft Location
The camshaft can be located in either the engine block (cam-in-block) or the cylinder head (overhead cam).
A cam-in-block engine is also called an overhead valve (OHV) engine. Push rods in a cam-in-block engine operate the rocker arms and valves.
No push rods are used in an overhead cam (OHC) engine, because the cam shaft is located at the cylinder head, where it can directly act upon the valves (or with only a rocker arm). The advantages of an overhead cam engine are a.) lower valve train weight because of reduced parts and b.) improved high-RPM efficiency.