Wright R-2600 Twin Cyclone
The Wright R-2600 Cyclone 14 (also called Twin Cyclone) is an American radial engine developed by Curtiss-Wright, and widely used in aircraft in the 1930s and 1940s. == History == In 1935, Curtiss-Wright began work on a more powerful version of their successful R-1820 Cyclone 9.
Source: Wikipedia — Wright R-2600 Twin Cyclone (CC BY-SA 4.0)