Data regarding the condensation of water on engine-cylinder walls when running the engine at comparatively low temperatures were presented by the author in a previous paper to which he refers. These experiments showed that no water would be deposited when the cylinder-wall temperature exceeded 110 deg. fahr. but that the rate of deposition increased in direct proportion to the drop of temperature below 110 deg. fahr.
His present paper describes laboratory tests of an engine equipped with a steam cooling-system, the object being to study the effect upon dilution of high cylinder-wall temperatures. The results show that a sharp reduction in dilution occurs as the boiling temperature is reached, and that the amount of dilution at temperatures of 212 deg. fahr., or more, is much less than would have been anticipated from the results obtained at temperatures below 212 deg. fahr. The author then points out that high cylinder-temperatures reduce dilution to a negligible quantity without introducing any apparent disadvantages.
The fact that the elimination of dilution inevitably will produce lubrication troubles, due to the higher viscosity of oil which will prevail, is emphasized, and various methods by which oiling systems can be modified so as to approach nearer to the ideal condition are suggested.
