BEGINNING with a statement of the requirements of a high-temperature cooling-liquid and a short history of what had been previously done in this field, the author gives a description of the liquid used in the investigation which was conducted by the Materiel Division at Wright Field.
The investigation is divided into five parts which includes dynamometer test of Curtiss V-1570 and D-12 engines, endurance test and flight tests of D-12 engine and a dynamometer test of a high compression-ratio D-12 engine. The engines and cooling systems used, the results obtained and troubles experienced are given in detail, with curves, sketches and views of the airplanes.
Extremely low fuel-consumption was obtained, and the results show that the ratio of installed weight to power of a liquid-cooled airplane-engine is considerably reduced by using this system of cooling.