Abstract: The rotary engine has a circumferential main chamber and at least one smaller combustion chamber spaced from the main chamber. The rotor includes a plurality of radially-projecting sealing members in spaced relationship thereabout for maintaining a fluid-sealed condition along a single fixed transverse strip area on the interior surface of the main chamber. A single radially-oriented axially-parallel piston vane is also carried by the rotor and moves through the fixed strip area of the main chamber at each revolution of the rotor. Plural passages for intake, compression, expansion, and exhaust are ported into the main chamber at locations proximate to the fixed strip area. Valve means in the passages selectively open and close the same for a cycle of engine operation involving intake, compression, burning, and exhaust.