The Murray engine is the earliest American supercharged engine still in existence. In 1911, Joseph J. Murray began design of air-cooled, valveless, 2-stroke, supercharged rotary engines, with the first tested early in 1912. The engines were developed by the Murray-Willat Company, and built by the American Motors and Aviation Company, where Murray briefly served as Secretary-Treasurer. Murray engines were built through 1914.
This model followed the original 18.6 kW (25-hp) engine, which had a supercharger based on the Roots principal, whereas this second prototype used a positive pressure-type supercharger driven at crankshaft speed and located between the crankcase and the accessory section. Murray’s engines never flew, but this artifact was installed in a Murray designed monoplane that served as a prop in two early movies produced at Mack Sennett’s Keystone Studios, “Saved by Wireless” and “Civilization.” The aircraft was heavily damaged during production of “Civilization” and apparently not used again.
Gift of Miss Vera C. Murray.
Country of Origin: United States of America
Diameter 73.7 cm (29.0 in.)
Type: Rotary, 6 cylinders, air-cooled, 2-stroke, supercharged
Power rating: 52 kW (70 hp) at 1,200 rpm
Displacement: 6.14 L (374.52 cu. in.)
Bore and Stroke: 100 mm (3.94 in) x 130 mm (5.12 in)
Weight: 118 kg (260 lb)