Abstract: A two piece intake valve for internal combustion engines comprising an inner and an outer valve which can be designed with orbicular heads. The inner valve including a stem of a smaller outer diameter than the outer valve. The outer valve including a hollow stem large enough to accept the inner valve stem, an inner valve guide, and an inner valve control spring and retainer mechanism. The outer valve also including a valve seat in the center of its bottom face to seat the inner valve. The head, or base, being equipped with one or more vents which communicate between the intake port and the combustion chamber and being releasably opened and sealed off by the inner valve. The vented valve unit incorporating an independent actuation means by way of pressure differentials created by the induction cycle, and/or directional inertia factors of the mechanically controlled valve element. The vented valve unit also incorporating design features to effectively control and dampen inner valve closing.

Abstract: A two piece intake or exhaust valve for internal combustion engines comprising an inner and an outer valve which can be designed with orbicular heads. The inner valve including a stem of a smaller outside diameter than the outer valve. The outer valve including a hollow stem large enough to accept the inner valve, and also including a valve seat in the center of its bottom face to seat the inner valve. The head, or base, being equipped with one or more vents which communicate between the intake port and the combustion chamber and being releasably opened and sealed off by the inner valve. The vented valve unit incorporating an independent actuation means by way of pressure differentials created by the induction cycle, and/or directional inertia factors of the mechanically controlled valve element.

Abstract: A two part intake or exhaust valve comprising an inner and an outer valve, both circular in shape, with the inner valve having a longer stem of a smaller radius to extend above the outer valve. The outer valve has a hollow stem large enough to accept the inner valve, also a valve seat in the center of its bottom face to seat the inner valve, and the top side of its base is equipped with vents. Both valves have separate springs of appropriate size affixed under valve spring retainers and retainers locked in place with retainer locks. The inner valve is equipped with a groove under the retainer to accept a heavy clip or stop disc. The purpose of this valve mechanism is to create a two stage event when atmosphere enters or exits a combustion chamber. This will allow more atmosphere to enter or exit the combustion chamber than is possible with a single valve arrangement.