Charles Lawrance designs for air-cooled engines began in 1915. In 1921, his own small company’s J-1 149 kW (200 hp) engine was designed for a Navy contract. Wanting a better, compact, lightweight engine not plagued with water leakage problems for use on aircraft carriers; the Navy encouraged the 1923 merger with the larger Wright Aeronautical Corporation. The Lawrance engine then progressed through the Wright Whirlwind J-3, J-4, J-5, and J-6 series, with the fully supercharged, high compression R-760-E2 certificated in December 1935. However, the most famous of these models was the J-5 which powered Lindbergh’s Spirit of St. Louis.
The first model in the seven-cylinder Wright Whirlwind R-760 (J-6) series was certificated in 1929. The J-6 powered aircraft such as the Stinson SM-2AC, Waco CRG/CSO, Curtiss-Wright CW Sedan 15-D, Curtiss-Wright Travel Air 4-D/10-2. Other R-760 engines powered aircraft such as the St. Louis PT-15, Howard UC-70C, Fairchild UC-88, Fairchild JK-1, Fairchild F-45, and Naval Aircraft Factory N3N-1/-3.
This object is not on display at the National Air and Space Museum. It is either on loan or in storage.
Circa 1926
United States of America
PROPULSION-Reciprocating & Rotary
Wright Aeronautical
Type: Reciprocating, 7 cylinders, radial, air-cooled
Power rating: 239 kW (320 hp) at 2,200 rpm
Displacement: 12.39 L (755.93 cu in.)
Bore and Stroke: 127 mm (5.0 in.) x 139.7 mm (5.5 in.)
Weight (dry): 259 kg (570 lb)
Length 114.3 cm (45 in.), Width 114.3 cm (45 in.), Height 114.3 cm (45 in.)
Aluminum
Steel
Leather
Paint
Copper Alloy
Rubberized Fabric
Felt
Paper
Magnesium Alloy
A19660462000
Found in the collection
National Air and Space Museum
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