Centric Reciprocating ENGINECR-Engine

Concept and Prototype Description of the CRE Engine

One of OTECHOS’ unique technology products is the CRE engine, which is a totally new engine technology.

About the Technology

CRE are the initials for ”Centric Reciprocating Engine”, which is an internal combustion engine, where a pair of two rotors move uniformly and are related to one another around a common centre axis, – further rotating simultaneously around the very same axis, creating chambers performing the phases of suction, compression, expansion and discharge of the exhaust gases.

These movements can be considered similar to those of a piston and cylinder in a conventional 4-stroke piston internal combustion engine, and even the respective diagrams are relative comparable. The control of the rotors, as well as the transfer of torque and the synchronisation are secured by a mechanical Control Unit which as well as the Motor Unit is practically vibration free, – from the inertia point of view.

CRE differs from the classes of both rotary engines and piston engines. When compared to these, the CRE presents a unique use of geometry far from the rotary engine which is tied up in its epitrochoidal eccentric geometry, causing its sealing problem, high oil consumption and low thermal efficiency. Also the CRE does not have the piston engines relatively complicated mechanical construction.

This means the CRE:

  • Is an engine that has only two active parts in the engine combustion compartment, which compares well to the performance of an eight cylinders 4-stroke piston engine
  • Does not possess any mechanical valves, it has two ports only for intake and exhaust gas exchange, – one inlet / intake and one exhaust / outlet.
  • The ignition is provided by a single spark plug or as on the prototype; two plugs in toggling parallel. Further using a single coil (in the prototype also two), and no distributor, – and all fully electronic controlled. By diesel process one single injection nozzle would be used.
  • It has a very small footprint and extremely low weight.
  • A relation between the surfaces in the combustion chamber versus cycled volume that is lower than that of a piston engine, clearly points to lower thermal loss and a higher efficiency. Which means less mechanical losses. Reduced fuel consumption in the order of 20 % is calculated when compared to that of a modern car engine.
  • Interface with non touching, dynamic sealing between the rotors provides an engine free from lubricating oil consumption, and eliminates gases result from cracking oil and oil film. Hydrocarbon (HC) emissions would therefore be zero.
  • CRE can be adapted to use turbo chargers in the same way as conventional piston engines. Additionally, it also has the benefit of not having the disadvantages of piston engines regarding simultaneously opening of the inlet and exhaust valves.


The Prototype (CRE X1) is built as an approx. 250 HP (186 kW) suction engine with a respired volume of 1.15 litres (0.304 US Gal), corresponding to 2.3 litre (0.61 US Gal) stroke volume of an 8 cylinders, 4 stroke piston engine. Typical it has a circular shape with a diameter of 320 mm (13 inches) and a length of 570 mm (22.4 inches), also includes the coupling to the brake on the test bench. The engine is built in a ”solid state”, having a coherent body containing the Motor Unit (A) and the Control Unit (B), as shown in the angle mixed section view (left). The prototype is rather well proportioned as a result of the parts being machined out of solid blocks, where no special respect to the weight of stationary parts has been taken by its whole design. Still the weight is only approximately 68 kilo,(150 lbs).

The CRE Engine can in addition to be used individually also be used together with OTECHOS’ unique technology, the CRC compressor and the CRP pump. The CR technology is patented.

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UK enquiries – CR Engine

OTECHOS ENGINES LIMITED | 123 Russel Road, Moseley, Birmingham, England, B13 8RS

Enquiries: CEO Tor Arne Hauge, phone: +47 90 16 90 70, email: torarne@otechos.com

web: http://othechos.com/cr-technology/cre/

Registered in England & Wales No: 10061148, VAT Registration number: 235 4129 24, EORI: GB235412924000, company no. 10061148

Enquiries, rest of the world

OTECHOS AS – PO Box 110, 4902 Tvedestrand – Norway

CEO Tor Arne Hauge, phone: +47 90 16 90 70, email: torarne@otechos.com