Abstract: The present invention discloses an improved control apparatus for a Diesel engine. The control apparatus includes an auxiliary intake air throttle device as well as a conventional main throttle device, which is actuable and throttles intake air only during engine idling and light-load operation in order to reduce the engine noise. The apparatus is further provided with a fuel metering device for ensuring the precise control on fuel metering when the auxiliary intake air throttle device is actuated so that the engine stall may be prevented.

Abstract: A carburetor equipped with a cooling system composed of cooling fluid passages incorporated in the carburetor flange and/or heat insulator mounted below the flange portion, said cooling system being supplied with cooling fluid only for a predetermined duration from the instant of opening the ignition switch to protect the carburetor casing from being overheated by an intake manifold incorporating exhaust gas heating.

Abstract: A thermal reactor for an internal combustion engine wherein when the temperature of the engine is low, exhaust gas exhausted from the engine is reacted in an inner core before it is mixed with secondary air and then guided to a riser member where it is heat-exchanged with intake gas mixture and thereafter exhausted through a bypass passage, and when the temperature of the engine is moderate to high the exhaust gas is mixed in the inner core with the secondary air introduced into the inner core through the vicinity of the riser member, whereby unburnt component in the exhaust gas is burnt and exhausted.

Abstract: A main combustion chamber that permits efficient combustion throughout the entire rotation range comprising a groove extending diametrically from an edge portion of the top surface of a piston and a pair of twin-leaved recesses branched from amidst the groove, each one of the pair of twin-leaved recesses have an edge portion that is circular or otherwise. Both the groove and the recesses are formed in the top surface of a piston of a swirl chamber type diesel engine.