CYLINDER-TEMPERATURE CONTROL BY EVAPORATION 260014
Any cooling-system is, in reality, a cylinder-temperature control-system. The best operating-temperature depends upon fixed physical characteristics of metals, oils and gases. The advantages of a fixed temperature of 212 deg. fahr. under all operating and weather conditions are: Reduced piston-friction, better vaporization, elimination of crankcase-oil dilution, and prevention of rusting, thereby increasing the life of the engine. A method of determining the cylinder-wall temperatures is described and a comparison of the temperatures for water and for steam-cooling under various operating-conditions shows that, with steam-cooling, the hot-spots are no hotter and the cooler parts of the cylinder have a more nearly uniform higher-temperature.
A description of the Rushmore steam cooling-system is given, together with the reason for the design of each part and a method of calculating its size. No change is necessary in the cylinder-block, the water-pipes are of very small size, the steam-pipe is about the same size as for water-cooling, the radiator core is capped and vented for steam distribution, a drain from the upper tank to the lower tank of the radiator permits running with the radiator full of water, the lower tank is enlarged for reserve water-supply, the air relief-valve has no function while the engine is running and the water-pump must have stainless-steel gears and shafts and be located below the reserve water-tank.
A simple and effective steam-heater for the body is supplied by small pipes and the amount of heat is constant whenever the engine is running. A hot-water-jacketed oil-pan can be used to control the temperature of the oil, thereby preventing the accumulation of diluent in winter and cooling the oil in extreme conditions in summer. The author states that engines of the future will be steam-cooled and covered with an insulating jacket to prolong greatly the cooling-off time after the engine has stopped.