The RCV is a 4-stroke spark ignition engine. The RCV has significant advantages over other internal combustion engine technologies:-

    • It has a near-ideal Combustion System, ensuring efficient operation on all major fuels types.
    • High power. The large opening areas of the RCV valve enable high power densities to be achieved, whilst retaining the fuel efficiency and low emissions of a 4-stroke.
    • Fuel efficient / low emissions. the RCV operates on a conventional 4-stroke cycle. This means the engine is inherently fuel efficient and has low emissions.
    • Simple / low cost. The simple construction of the engine, in particular the Horzontal Valve version, means the engine can be produced at a very competitive cost.

Links to Papers

“The RCV Engine. Technical Analysis and Real World Benefits”, IMechE Conference, London, 2011.

“Operation of a Rotating Cylinder Valve 4-stroke Engine on Heavy Fuel for UAV Applications”, AUVSI Conference Washington DC, 2007.

“The Development of a Rotating Cylinder Valve Engine for 2 Wheeler Applications”, SIAM Conference, New Delhi, 2004.

“The Rotating Cylinder Valve 4-stroke Engine a Practical Alternative”, SETC Conference, Kyoto, 2002.

        The RCV Combustion system
        The combustion system is the mechanical arrangement that compresses, ignites, burns and extracts power from the air/fuel mixture. The RCV combustion system has the following characteristics:-

            • Compact. This minimises the amount of heat lost into the body of the engine. It also minimises any tendency for detonation of trapped pockets of air/fuel mixture.
      • Uniform surface temperatures without any hotspots. This is because all moving components are exposed to an equal amounts of inlet and exhaust gas, and there is no hot exhaust valve as on a conventional 4 stroke. This minimises any tendency for detonation, and reduces carbon formation.
      • High turbulence. The rotating action of the valve, together with the large squish band around the valve, lead to high levels of turbulence. This propagates the flame front more quickly through the mixture.
      • It has an ignition point near the centre of the chamber.


As a result the engine runs efficiently on all the major fuels:- gasoline, JP8 / JP5 / kerosene. On all these fuels it runs in a predictable manner and is insensitive to changes in fuel composition. The engine is easy to tune with performance being maintained over a wide band of ignition timing and mixture. All fuels are run using spark ignition. Operating on gasoline or any of the kerosene based fuels, power and fuel consumption are similar. Operating on diesel fuel requires controlled conditions, and power will be around 5 - 10% less, and fuel consumption around 10% greater. Both diesel and JP8 / JP5 / kerosene require pre-heat to start the engine. Once at full operating temperature the engine handles and functions as with gasoline.


High Power
The RCV rotary valve has a large opening area. This enables it to achieve high volumetric efficiency at high speeds. As there are no reciprocating elements there are no valve related mechanical limitations to RPM. The combination of these two elements mean the engine can achieve high speed, high specific powers, and high power to weight. It has comparable specific power output to a 2-stroke engine.


Fuel Efficient/Low Emissions
The RCV employs a conventional 4-stroke cycle and it therefore has the fuel efficiency and low emissions levels of a 4-stroke. The efficient combustion system contributes to this aspect of the engine’s performance.


Simple / Low Cost
Following extensive development, the RCV rotary valve is now a simple one piece cylindrical component, with readily achievable tolerance limits, an no complex sealing rings or other seal components.
The valve system uses carefully chosen materials that result in a thermal self-regulation mechanism. This automatically maintains the tight sealing tolerances required for efficient operation over the operating temperature range of the engine.
The design is practical and long lasting, and readily achieves the durability requirements for small engine applications.
Particularly in its horizontal configuration this simple design is suited for low cost/high volume production.
The unique features of the valve that make the RCV work reliably and predictably have been patented. This means that any engine development undertaken in partnership with RCV will automatically have strong patent cover.