Abstract: The invention is directed towards a fuel enrichment system for a multi cylinder internal combustion engine. Each cylinder of the engine is served by a separate carburetor. Manifold passageways are interposed between the cylinders and the respective carburetors for supplying the fuel/air mixture to the cylinders. The system further includes a balance passage which provides communication between each of the passageways. A starting fuel/air mixture is delivered to the cylinders through the balance passage.

Abstract: A multi-cylinder internal combustion engine with an intake valve and a throttle valve respective to each cylinder. A respective intake passage interconnects each throttle and intake valve. At least one element of a charge flows through the intake passage. An intake balance conduit includes a plurality of branches and interconnects a plurality (preferably all) of the intake passages. The branches discharge into their respective intake passages at an acute angle relative to the direction of stream flow in the intake passage, preferably substantially downstream from the throttle valve. Exhaust gas recirculation means can optionally discharge into the conduit, preferably substantially downstream from the throttle valve.

Abstract: Several embodiments of internal combustion engines offering improved performance in the form of improved fuel economy and reduction in the emission of unwanted exhaust gas constituents at idle and low speed operation. In each embodiment, an induction system is employed using a main intake passage and a sub-intake passage, each of which communicates with the combustion chamber through a respective port. The sub-intake passage has a substantially smaller cross-sectional area than the main intake passage so that a given mass flow through this passage will enter the combustion chamber at a higher velocity than that flowing through the main intake passage. Throttle valve means are provided for sequentially controlling the flow into the combustion chamber through the main and sub-intake passages.

Abstract: Controls for induction systems of fuel injection supplied internal combustion engines in which the induction system flows from an air amount detection means to combustion cylinders, through a main or principal intake passage and a sub-intake or shunt passage. Fuel injection means discharges fuel into the main intake passage in amounts determined by the detection means. The sub-intake passage directs air in a jet stream into the combustion chamber to cause turbulence therein. The sub-intake passage discharges into the combustion cylinders at a substantially different angle from the main intake passage and intersects the discharge from the fuel injection means to improve the fuel air mixture entering the combustion cylinders.

Abstract: Several embodiments of an induction system for internal combustion engines that improve volumetric efficiency and combustion efficiency throughout the engine speed and load ranges. In each embodiment, each chamber of the engine is provided with two intake valves and a spark plug that is symmetrically dispositioned in the chamber. The induction system includes auxiliary induction passages through which the major portion of the engine idle and low speed charge requirements are supplied. The auxiliary induction system is oriented so that the charge will be induced into the chambers at a high velocity and in a flow pattern so that the charge passes the spark plug at the time of ignition. In accordance with a further feature of the invention, a throttle valve is provided in the induction system, which throttle valve is rotatably supported in an insert that is interposed between the charge forming device and the engine chambers for controlling this flow.