DURING the first two years of the war the author conducted in England experimental work for the British Government on the engine he describes. After brief mention of V-type water-cooled engines and the general situation as regards revolving air-cooled and radial water-cooled types, the discussion is narrowed to two distinct designs of fixed radial air-cooled engine, both of which have been tried out and seen some service.
The fundamentals in which fixed radial air-cooled engines give promise of excelling are weight of powerplant per horsepower, the fuselage mounting and space required being duly considered; reliability and durability; fuel and oil consumed per horsepower-hour; streamline mounting, with armor, if desired; quick detachability of powerplant; accessibility, and freedom from certain inherent difficulties peculiar to water-cooled engines. As these several matters are discussed many points are brought out to show the details of modern construction, shop practice under certain difficulties, the new roller bearing, a connecting-rod layout, British figures on fuel consumption, mounting advantages and disadvantages, and cooling construction problems.
It is assumed that an engine possessing the inherent advantages claimed will be further perfected and come into wide use.