A backpack-sized unmanned aerial vehicle from Honeywell will likely use a 60-cc engine designed and built by RCV Engines Ltd., Brighton, U.K. (rcvengines.com).
It should deliver 4.2 bhp at 8,200 rpm, and run on JP8, as well as a variety of other fuels.
RCV engines have the same induction, compression, power, and exhaust strokes as a conventional four-stroke engine. But in conventional engines, gasses enter and leave cylinders via poppet valves in the cylinder head which are operated by a mechanical valve train. In the RCV engine, the cylinder is mounted on bearings and rotates at exactly half the crankshaft rotational speed. It is driven from the crankshaft either through a gear train or toothed belt. The cylinder also has a large port and combustion chamber. When the port lines ups with a hole in the turning cylinder, it opens the intake or exhaust ports. Conversely, the intake and exhaust ports are closed when the port is not aligned with the hole. This technology, which is ideal for under-250-cc powerplants, reduces manufacturing costs, lowers emissions, and tends to generate stable, high-speed performance.