| abstract |
The invention concerns a method of operating an engine (18) having a variable volume working chamber (24, 26), e.g. a piston engine. According to the invention, working fluid driving the engine comprises any of a halocarbon, a halo-hydrocarbon, a partially halogenated carbon compound, a fluorocarbon, a perfluorocarbon, a hydrofluorocarbon, a hydrochlorofluorocarbon, a fluorinated ether, a fluorinated ketone, or a functional derivative of any of the aforegoing. |