Abstract: Several embodiments of internal combustion engines each having an arrangement for increasing turbulence in the combustion chamber under at least certain load and/or speed conditions so as to permit the use of a relatively simple spark advance mechanism. In each embodiment, the flame propogation is controlled by controlling the degree of turbulence to achieve the desired effect. The turbulence is generated by causing induction of at least a portion of the engine charge requirements through a relatively small cross sectional area auxilliary induction passage. Because of the small cross sectional area, high flow velocities are generated which are maintained in the combustion chamber. In accordance with certain embodiments of the invention, the degree of turbulence is controlled by either shunting some of the air flow through the main induction passage or by introducing controlled amounts of exhaust gas products.

Abstract: Several embodiments of internal combustion engines having relatively large main induction passages and relatively small auxiliary induction passages for delivering a charge to the chambers of the engine. Valve means control the proportion of flow to the chambers through the respective passages so that the low and medium charge requirements are supplied primarily by the auxiliary induction passage. This causes improved turbulance in the chamber at the time of combustion and promotes smooth running, good fuel economy and reduction in unwanted exhaust gas constituents. In conjunction with one feature of the invention, means are provided for accelerating the rate of valve movement during the transition from mixture supply from the auxiliary to the main induction passages to improve performance. In accordance with another feature of the invention, an arrangement is provided for permitting compact placement of the control valves.

Abstract: An internal combustion engine having a relatively large main induction system that supplies the engine charge requirements at partial and full load and a relatively small cross-sectional area auxiliary induction system that provides the charge requirements at idle and low load conditions. An exhaust gas recirculating system is also incorporated with a control whereby exhaust gases are recirculated to the engine combustion chambers only at the time when the auxiliary induction system is supplying the major portion of the engine charge requirements. This permits effective combustion control without necessitating modifications to the conventional spark timing device of the engine.