or alternative fuel injection means may be used e g carburetors the aforementioned engine has the following advantages i the rotor rotates concentrically and the engine is reversible therefore it disperses with the crankshaft crossheads piston and connecting rods or a reversing gearbox which are commonly used in conventional two and or four stroke reciprocating piston engines and it also dispenses with eccentric gears commonly used in 34 wankel 34 type rotary engines furthermore since the stator casing is of a uniform cylindrical shape the angle of contact between the seals fitted along the radially outer end face of the rotary piston and the inner peripheral surface of the stator housing as well as the angle of contact between the seals fitted along the radially inner face of the operational radial sealing wall and the peripheral surface of the rotor hub are constant throughout the rotation of the rotor and thus restrict seal wear to a minimum ii the engine operates on the one stroke principle therefore its geometry and 360 degree cycle of operation allow the combustion gasses to expand against the rotary piston in the rotor space throughout up to 294 degrees of rotation i e in excess of 80 of the engine cycle of operation and.