A rotary internal combustion diesel engine (46) comprising: a posterior plate (78), an intermediate plate (80), and an anterior plate (82); a rotor-housing unit (46) on each side of the intermediate plate (80), each containing a yousroid chamber (48), and a 2-apex rotor (56) containing an aperture (58). The chamber (48) wall contains an intake valve (68), an exhaust valve (70), and a fuel supply device (72); in gasoline embodiments, an ignition device (76) is added; compressed air/gas and hydraulic embodiments, require an input port (74) and an output port (70a). A shaft (52) rotatably mounted, extends through the housing, having essentially rectangular segments (54) within the chambers (48). There are seals (not shown) on the rotor apices (60, 62) and on the anterior (82) intermediate (80), and posterior plate (78).