The camshaft sits above the cylinder head rather than down in the block. Double overhead cam gives each bank two shafts, allowing four valves per cylinder and higher safe revs.
Overhead cam (SOHC / DOHC)
Engine
in short
Engine
The camshaft sits above the cylinder head rather than down in the block. Double overhead cam gives each bank two shafts, allowing four valves per cylinder and higher safe revs.