Abstract: A rotary valve with means for effecting variable timing of intake valve opening, variable opening duration and variable timing of closing in response to changes in each engine cylinder's appetite for an intake charge is disclosed. Earliest valve opening, longest duration and latest closing occur when each cylinder's appetite for an intake charge is largest, while latest opening, shortest duration and earliest closing occur when each cylinder's appetite for an intake charge is smallest.Intake valve timing can be varied sufficiently to permit use of the theoretical Top Dead Center Opening and Bottom Dead Center Closing for idle, low speed and coasting operating modes to the typical average 20 degrees Before Top Dead Center Opening 50 degrees After Bottom Dead Center Closing for high speed-high load operating mode.

Abstract: A rotary valve for an internal combustion engine comprises an outer stationary support member formed with a hollow interior, an inner valve member housed within the hollow interior, and bearing means supporting the valve member for rotation about an axis at one-half or one-quarter engine speed, depending on the embodiment. The outer support member and the inner rotatable member are formed with port and duct means of various configurations for selectively enabling and preventing the flow of intake and exhaust gases through the valve in accordance with the angular position of the inner rotatable member with respect to the outer support member. Annular and strip seals are mounted between opposing surfaces of the outer support member and the inner rotatable member to prevent leakage of gas therebetween. A portion of the duct means formed in the outer support member serves also as a portion of the combustion chamber.