Pratt & amp; Whitney (Hornet) R-1690
In 1926, Pratt & amp; Whitney enlarged variant of the Wasp engine. This 9-cylinder air-cooled radial (star) engine with a displacement of 27.7 dm3 was given the factory name Hornet A. However, the military designation R-1690 is better known. Several versions have been created (see below). As a power unit, it was built into a number of aircraft. Production ran from 1926 to 1942, with a total of 2944 of these engines produced.
Version:
Hornet A: with an output of 525 horsepower (391 kW)
R-1690-11: 700 horsepower (521 kW)
R-1690-13: with an output of 625 horsepower (465 kW)
R-1690-52: 750 kW horsepower (559 kW)
source: cs.wikipedia.org
Edit: Janko PALIGA, addition, new link
In 1926, Pratt & amp; Whitney enlarged variant of the Wasp engine. This 9-cylinder air-cooled radial (star) engine with a displacement of 27.7 dm3 was given the factory name Hornet A. However, the military designation R-1690 is better known. Several versions have been created (see below). As a power unit, it was built into a number of aircraft. Production ran from 1926 to 1942, with a total of 2944 of these engines produced.
Version:
Hornet A: with an output of 525 horsepower (391 kW)
R-1690-11: 700 horsepower (521 kW)
R-1690-13: with an output of 625 horsepower (465 kW)
R-1690-52: 750 kW horsepower (559 kW)
source: cs.wikipedia.org
Edit: Janko PALIGA, addition, new link