Abstract: An improved two-cycle Diesel internal combustion engine is provided, whereby the intake and exhaust port passages are modified to provide greater circulation of the combustible fluids and air during the intake and exhaust cycles of the Diesel engine, respectively. The intake passages are so located in each piston and each cylinder to provide communication thereinbetween during the intake cycle with the piston at the bottom of its stroke which effects the exhaust cycle simultaneously substantially similar to a normal two-cycle operation. The intake passages in each cylinder communicate with intake passages in each piston which are connected to an intake flume port located epicentrically in the upper portions of each piston. The movement of the combustible fluids and the evacuation air is directed from the intake flume port and deflected off a conical protrusion in the upper surface of the cylinder, in order to promote circulation of the combustible fluids and the evacuation air, respectively.