Abstract: A model airplane engine uses a heated backplate to replace the conventional, non-heated backplate of the engine. The backplate incorporates a heater, which is electrically, temporarily energized during the start cycle of the engine. The higher temperature of the engine results in vaporization of the fuel prior to its entry into the combustion cylinder thus preventing crankcase and cylinder flooding and allowing easy starts during operation in cold weather, and also makes possible the use of inexpensive low-volatility heavier fuels, rather than special, expensive fuels.

Abstract: The invention comprises a method for ram accelerating a projectile which comprises charging a tube, having an inlet end for accepting the projectile and a muzzle end from which the projectile may leave the tube, with a combustible gas mixture at an initial elevated pressure in the absence of combustion, so that the projectile may be accelerated by combustion of the mixture behind the projectile as it passes through the tube from the inlet end to the muzzle end; introducing the projectile into the inlet end; igniting the combustible gas mixture between the projectile and the inlet end; and creating the elevated pressure within the tube by means of a shock wave within the combustible gas mixture to obtain the elevated pressure before the projectile passes through the gas. Desirably, a static elevated gas pressure is created at least just prior to passage of the projectile through the gas.The invention further includes a ram accelerator for practicing the method of the invention.