Abstract: Objects of a cylinder cover for diesel engine is to prevent the interference of mists between a plurality of fuel valves, thereby enhancing the spray efficiency, and to prevent troubles of burning of nozzle caused by the collision of mist sprayed from the adjacent fuel valve and increase in thermal stress caused by local overheat of combustion chamber surface due to the collision of mist. To achieve these objects, fuel valves are mounted in a side wall of the cylinder cover so that the centerline thereof is substantially at right angles to the cylinder centerline. Further, the injection angle of the fuel valve is set so as to be an acute angle not larger than 90.degree. to prevent local collision of mist with the combustion chamber wall surfaces, and the volume of the volume portion at the tip of the fuel valve is decreased to the minimum.

Abstract: An object of the invention is to provide a diesel engine of water injecting type having fuel injecting valves and water injecting valves wherein water mists are adapted to reach high-temperature regions of fuel mists so that the temperature can be reduced to inhibit the generation of NOx. In order to achieve the object, the fuel injecting valves and the water injecting valves are arranged separately in different sites, ones in the top wall of the cylinder cover and the others in the side wall, so that high-temperature regions of fuel mists are mixed with water mists in right angles to each other to lower the combustion temperature thereby reducing the generation of NOx.