A power system including a variable volume combustion chamber for a two-stroke engine having a controlled exhaust port, a fuel injector to the combustion chamber and an oxygen injector to the combustion chamber. The oxygen injector provides repeated oxygen injection pulses to complete a charge. The controlled exhaust port includes an oscillating rotatably mounted valve. A source of pressurized concentrated oxygen to the oxygen injector is in a closed case having a ceramic fiber membrane. An air inlet and a waste outlet are in communication with a first side of the ceramic fiber membrane. An oxygen outlet is in communication with a second side of the ceramic fiber Ionic transport membrane. The case has a heat transfer surface in communication with the controlled exhaust port from the combustion chamber.