Rotary Engine Development Agency

Currently automotive engines are generally reciprocating or Wankel rotary engine types. Reciprocating engines are bulky, heavy and complex, mainly due to the intake and exhaust valves and their associated cam-train. Wankel engines have a low rotor rev limit, and have inefficient sealing of the apex seals leading to poor economy and undesirable emission gases. 


The Rotary Engine Development Agency (REDA) has designed a new three-chamber rotary internal combustion engine concept using the K-curve, an amended form of its patented Szorenyi Curve. The paper linked below describes the features of the new three-chamber engine concept and includes an analysis of the major shortcomings of the Wankel engine.


The Szorenyi K-Curve Three-Chamber Rotary Engine



The apex of a triangle in contact with a racetrack traces out a recognizable four-leaf clover as it rotates. The shape of the racetrack in its mathematical form has been US patented, No 6,718,938 B2.

The racetrack forms the engine casing inside which the engine segments rotate. 


The concept for the engine was conceived over 15 years ago. After much work, effort and development, it was brought to reailty in 2008 by its inventor, Peter Szorenyi.


The Engine was awarded an ACT Research and Development Grant of $63,000 in

2001. Since that time, three prototypes of the engine have been produced and the design refined. A “proof-of-concept” engine run was achieved on February 26, 2008. The current prototype is assembled and ready for further testing. 


Suitable parties are sought for the future development of the engine.  Those interested are encouraged to contact REDA through the Contact section.


  • Four-chamber Szorenyi rotary first run under its own power February 26, 2008.
  • SAE Paper 2017-10-2413 presented in Beijing, October 2017.
  • SAE Book "So You Want to Design Engines: UAV Propulsion Systems" featuring the Szorenyi Engine published in 2018.
  • Three-chamber rotary concept developed in 2018.
  • Featured in "Popular Mechanics," January 2019.


  • Three-segment rotor.
  • Internal combustion - Otto cycle.
  • Centre-line drive shaft provides a perfectly balanced rotor assembly.
  • Peripheral inlet and exhaust ports – no valving.
  • Higher apex seal efficiency than a Wankel rotary engine.
  • Multi-fuel capability - gasoline, natural gas, aviation kerosenes, diesel, hydrogen.
  • Three power strokes per crank shaft revolution.


  • Cars.
  • Motorcycles.
  • Light aircraft.
  • UAVs.
  • Portable generator kits.

Mr. Peter King:

(+61) 0413 841 148





PO Box 4127
Doncaster Heights 3109