Wright R-1670 Whirlwind
The Wright Whirlwind was a family of air-cooled radial aircraft engines built by Wright Aeronautical (originally an independent company, later a division of Curtiss-Wright). The family began with nine-cylinder engines, and later expanded to include five-cylinder and seven-cylinder varieties. Fourteen-cylinder twin-row versions were also developed, but these were not commercially produced.
The Whirlwind was a direct descendant of the Lawrance J-1, a nine-cylinder air-cooled radial built by the Lawrance Aero Engine Company for the U.S. Navy. Because the Navy was very enthusiastic about air-cooled radials, but was concerned that Lawrance could not produce enough engines for its needs, it forced Wright to purchase the Lawrance company in 1923 and build the J-1 itself. Wright's J-1 was the first engine in its nine-cylinder R-790 Whirlwind series.
During the mid-1930s, Wright developed two fourteen-cylinder double-row versions of the Whirlwind, the R-1510 of 600 hp (450 kW), and the R-1670 (Introduced 1934, prototype only) of 800 hp (600 kW). These were used in a number of military aircraft prototypes, but neither engine reached the production stage.