[Curmudgicus]

For anyone interested in engine efficiency tech, this website is fascinating. It deals with the Saint-Hilaire "Quasi-turbine" engine.

The engineers have come up with an infinitely configurable rotary engine that uses compression/expansion characteristics I usually associate with Stirling engines. The somewhat wankel-like "rotor" is articulated, and uses the distance between the rotor and chamber wall for compression/expansion. It is a low-RPM high-torque concept, and can be used for fossil fuel, steam, and hydrogen.

Their efficiency claims are hard for me to gauge, but the adaptibility of the engine is fairly obvious.

http://www.quasiturbine.com/ETheoryQTConcept.htm

[master_rb]

it might be efficient but it doesn't look like it's as durable as conventional engines at least to me