This is a tubular metal shaft that rotates in an engine and features cam lobes that control the intake and exhaust valves. You can find the camshaft within the engine block in overhead valve engines, and is situated just above the cylinder head in overhead cam engines. Most engines have just one camshaft, but a V-shaped (e.g., V6 or V8) single overhead cam engine will have two. An inline (e.g., a non-V-shaped 6-cylinder) dual overhead cam engine has two camshafts,whereas a V-shaped dohc engine has four cams.