Abstract: An exhaust gas purifying apparatus, for use in an automobile multi-cylinder engine of the type which has exhaust port ducts leading from engine cylinders and through which exhaust gases are emitted subsequent to combustion of an air-fuel mixture, the exhaust gas purifying apparatus having a reducing catalyst unit and an oxidizing catalyst unit disposed in a main exhaust manifold which is corrected on one side, to a first group of the exhaust port ducts and, on the other side to the atmosphere, an auxiliary exhaust manifold is connected, on one side to a second group of the exhaust port ducts and on the other side to a portion of the main exhaust manifold which is downstream from the reducing catalyst unit and upstream of the oxidizing catalyst unit.

Abstract: For use in an automobile multi-cylinder engine having exhaust port ducts leading from engine cylinders and through which exhaust gases are emitted subsequent to combustion of air-fuel mixture, an exhaust gas purifying apparatus which has a reducing catalyst unit and an oxidizing catalyst unit disposed in a main exhaust manifold connected on one hand to a first group of the exhaust port ducts and on the other hand to the atmosphere, and an auxiliary exhaust manifold connected on one hand to a second group of the exhaust port ducts and on the other hand to a portion of the main exhaust manifold at a position downstream of the reducing catalyst unit and upstream of the oxidizing catalyst unit. The apparatus further has a pressure operated valve disposed in a secondary air supply passage for introducing secondary air into the auxiliary exhaust manifold by the utilization of a pulsating flow of the exhaust gases through the auxiliary exhaust manifold.

Abstract: For use in an automobile multi-cylinder engine having exhaust ports leading from engine cylinders and through which exhaust gases are emitted, an exhaust gas purifying apparatus comprising a reducing catalyst unit and an oxidizing catalyst unit disposed in a main exhaust manifold communicated through exhaust ducts to a first group of the exhaust ports and, on the other hand, to the atmosphere, an auxiliary exhaust manifold communicated to a second group of the exhaust port and, on the other hand, to a portion of the main exhaust manifold at a position intermediately between the reducing and oxidizing catalyst units, a secondary air supply passage extending from a source of secondary air to the auxiliary exhaust manifold, and an additional secondary air supply passage extending from the secondary air source to any one of the collecting ducts communicated to the exhaust ports of the first group.

Abstract: Cylinder head construction defining a hemispheric combustion chamber and including a guide wall facing an intake port to impart swirl to an incoming air-fuel mixture and permit use of a lean air-fuel mixture. The position of the guide wall relative to the cylinder center and relative disposition of the guide wall and a spark plug are made such that although the guide wall is effective in imparting swirl, a flame front may be efficiently propagated to all parts of the combustion chamber subsequent to ignition of the air-fuel mixture therein, whereby provision of the guide wall does not result in increased emission of hydrocarbon compounds in exhaust gas or formation of carbon deposits in the combustion chamber.