A device and method for double actuating, by pressure differential, a valve of a combustion chamber of an internal combustion engine, wherein the double actuating device comprises an actuator piston displaceably arranged in an actuator cylinder between two chambers of inversely varying volume, mechanically attached to the stem of said valve. The actuating forces on said valve are selectively controllable via pressurized manifolds. The valves are double actuated independently of engine operation, the method allowing for variation in timing, duration, and lift under an electronically controlled fluid circuit, using alterable constants to allow for modifiable operating modes, also allowing reprogramming of said electronics to provide for in-place upgrades.