The present invention relates to an improved rotary engine having one positive motion stroke, the rotary engine comprising at least one of a piston having at least one piston vane. At least one of a unidirectional bearing is operationally coupled to the piston, wherein the piston is configured to allow the piston vane to rotate and the unidirectional bearing prevents the piston vane from rotating during a combustive force or a thrust force injection. A peddle block is positioned in the pathway of the piston vane, wherein as the piston vane approaches the peddle block a secondary exhaust pressure increases against the piston vane surface, the secondary exhaust pressure, in part, causes the piston vane to rotate and self-align for a subsequent cycle. Other exemplary embodiments allow for a secondary exhaust pressure to rotate a piston vane causing the piston vane to self-aligning for the next cycle.