Valve-actuating variable cam for engine

A valve-actuating variable cam for a reciprocating machine comprised of a camshaft journalled for rotation by said machine and driven in timed relationship with said machine, a first cam fixed upon said camshaft and rotatable with said camshaft, a second cam fixed for rotation with said camshaft and moveable relative to said first said cam in a direction radial to the axis of rotation of said camshaft, a shift rod slidably mounted within said cam shaft, said shift rod having a drive surface thereon driving a key element, said key element positioned within and engaging at least said second cam, means for moving said shift rod to a first position in which said first cam engages said valve, and to a second position in which said key pushes said second cam radially outwardly and said valve engages said second cam, wherein said means for moving includes a fluid passage extending through said camshaft and said shift rod, and a fluid port provided in said passage leading to a chamber adjacent a first end of said rod, wherein fluid flowing into said chamber moves said rod.