Abstract: An internal combustion engine has a primary intake passage including a primary throttle valve for supplying engine cylingers with an air-fuel mixture under a full range of loads, a secondary intake passage including a secondary throttle valve for supplying the engine cylinders with an air-fuel mixture under high loads, and an exhaust-gas recirculation passage including an exhaust-gas recirculation valve for introducing an exhaust gas into the primary intake passage. Vacuums at the primary and secondary throttle valves are utilized to control the exhaust-gas recirculation valve. A distributor for producing ignition sparks is also controlled by the vacuums at the primary and secondary throttle valves for ignition timing. The engine also includes a first mechanism for retarding ignition sparks and a second mechanism for promoting engine idling.

Abstract: The present invention relates to a four-cycle internal combustion engine in which a strong swirl can be generated within the combustion chamber through the directionality of the mixed gas supplied from the main suction path and the injection of a gas from the sub-suction path, and a heavier EGR than before can be carried out without detracting the engine performance, and NOx generation can be substantially reduced by EGR alone. In time of idling when a heavy EGR is needless, the gas injection from the sub-suction path is controlled to prevent a misfiring.

Abstract: A fuel for internal combustion engines is composed of a mixture of alcohol and gasoline in which the alcohol content is 70 to 85 volume % and the gasoline consists essentially of aromatic, alkanic and cycloalkanic hydrocarbons and, optionally, olefinic hydrocarbons the hydrocarbons having 3-11 carbon atoms, the aromatic hydrocarbons constituting 35 to 45 weight % of the gasoline and the aromatic and any olefinic hydrocarbons constituting cumulatively 35 to 60 weight % of the gasoline.

Abstract: The exhaust gas purification device includes an exhaust manifold, a purification cylinder connected with the exhaust manifold through a first honey-comb shaped catalyst, and a second honey-comb shaped catalyst positioned at the rear portion of the purification cylinder. Each catalyst is supported by steel wool rings including coarse and dense portions of steel wool. The purification device further includes a secondary air supplying arrangement.

Abstract: In a metal material having a surface adapted to slide on a surface having a nickel-silicon carbide composite electroplated layer and subjected to a treatment for causing silicon carbide particles to project outward beyond the surface, the surface of the metal material is provided with porous hard chrome plating, whereby a lubricant may be deposited and retained in the porous plated layer.