A rotary engine apparatus (40a, 40b) having: a housing defining a housing chamber; a plurality of elliptical rotors, each said rotor being mounted to a rotor shaft with said rotors being rotatable within said housing chamber; a valve disk mounted to a said rotor shaft for rotation with said rotor shaft, said valve disk having a first side and a second side with a port passing there between; a valve plate, said valve plate including a bore for rotationally receiving said valve disk therein with said bore defining a cylindrical sidewall; said valve disk (2000 including a radial edge wall with a groove disposed in said edge wall, and including a ring member disposed in said groove, said ring member contacting said sidewall of said bore when said valve disk is disposed in said bore; characterized in that said valve disk comprises an intake valve disk and said port comprises an intake port, and wherein said bore comprises an intake bore, and wherein said rotary apparatus further includes an exhaust valve disk mounted to another said rotor shaft for rotation there with, said exhaust valve disk having a first side and a second side with an exhaust port passing there between, said valve plate including an exhaust bore for rotationally receiving said exhaust valve disk therein with said exhaust bore defining a cylindrical sidewall, said exhaust valve disk including a radial edge wall with a groove disposed therein, and including another ring member disposed in said groove of said exhaust valve disk with said ring member of said exhaust valve disk contacting said sidewall of said exhaust bore when said exhaust valve disk is disposed in said exhaust bore. a housing defining a housing chamber; a plurality of elliptical rotors, each said rotor being mounted to a rotor shaft with said rotors being rotatable within said housing chamber; a valve disk mounted to a said rotor shaft for rotation with said rotor shaft, said valve disk having a first side and a second side with a port passing there between; a valve plate, said valve plate including a bore for rotationally receiving said valve disk therein with said bore defining a cylindrical sidewall; said valve disk (2000 including a radial edge wall with a groove disposed in said edge wall, and including a ring member disposed in said groove, said ring member contacting said sidewall of said bore when said valve disk is disposed in said bore; characterized in that said valve disk comprises an intake valve disk and said port comprises an intake port, and wherein said bore comprises an intake bore, and wherein said rotary apparatus further includes an exhaust valve disk mounted to another said rotor shaft for rotation there with, said exhaust valve disk having a first side and a second side with an exhaust port passing there between, said valve plate including an exhaust bore for rotationally receiving said exhaust valve disk therein with said exhaust bore defining a cylindrical sidewall, said exhaust valve disk including a radial edge wall with a groove disposed therein, and including another ring member disposed in said groove of said exhaust valve disk with said ring member of said exhaust valve disk contacting said sidewall of said exhaust bore when said exhaust valve disk is disposed in said exhaust bore.