Abstract: An engine induction system for reducing engine pumping losses provides for a minimum of two intake valves per cylinder, a primary and secondary, with valve port activation means associated with the secondary valves to control air flow to them so that at light loads only air flows through the primary intake valves, the secondary valves providing air flow at heavier loads, the primary intake valve openings being controlled so that no more than one primary valve is open at any one time; i.e., there is no overlap in openings between primary intake valves, which produces pumping losses at light loads when intake manifold vacuum is high.