Abstract: Secondary air is strategically introduced into a combustion chamber of an internal combustion engine event after the main combustion event to reduce HC and CO emissions. While the technique is applicable to virtually any otto cycle engine, it is particularly well-suited for use in a “rich burn” utility engine typically operating at an equivalence ratio (ER) of about 1.2 or above. Such engines start easily, run well, and emit low levels of NOx at ERs on the order of 1.2. The invention takes advantage of these benefits by admitting an air/fuel charge and allowing otto-cycle combustion to occur in at least generally the usual fashion (although at least preferably as rapidly as possible for a given engine design), using the standard fuel-rich carburetor calibration to fuel the engine.

Abstract: Secondary air is strategically introduced into a combustion chamber of an internal combustion engine event after the main combustion event to reduce HC and CO emissions. While the technique is applicable to virtually any otto cycle engine, it is particularly well-suited for use in a “rich burn” utility engine typically operating at an equivalence ratio (ER) of about 1.2 or above. Such engines start easily, run well, and emit low levels of NOx at ERs on the order of 1.2. The invention takes advantage of these benefits by admitting an air/fuel charge and allowing otto-cycle combustion to occur in at least generally the usual fashion (although at least preferably as rapidly as possible for a given engine design), using the standard fuel-rich carburetor calibration to fuel the engine.

Abstract: A single exhaust gas recirculation valve selectively provides flow distribution of exhaust gas from an engine manifold to a turbocharger or exhaust gas recirculation system, and simultaneously provides back pressure for driving the recirculated exhaust gas to the intake manifold of the engine when the valve is positioned to recirculate all or part of the exhaust gas. A "wing-type" throttle blade is rotatably positioned within the valve and is selectively positionable between a first blocking position at which the exhaust gas recirculation port is blocked, and a second position at which the flow of exhaust gas to the turbine section of a turbocharger is blocked, as well as intermediate positions between the two blocked positions. The bearings supporting a shaft, to which the throttle blade is attached, are water cooled, as well as a mounting flange and shell surrounding an electric stepper motor coupled to the shaft.

Abstract: A fuel injector valve controls both the metered flow of fuel and the metered flow of air into a mixing chamber, permitting intermittent, cyclic flow of both air and fuel into the chamber. The controlled cycling of both the air and fuel flow permits optimization of fuel performance. A single action valve and a dual action valve are disclosed. The air flow and fuel flow may be independently adjusted for maximum flexibility.