Wright P-1 Cyclone was a 9-cylinder 1654 cu. in. engine manufactured and tested in 1924 and was the fit in the series of Wright Cyclone engines. The P-1 was the fit "Large" (over 400 Hp.) air-cooled radial engine, noted for its unique valve train designed by Charles Lawrance.For more on the Cyclone and other Vintage Aircraft engines visit:https:www.enginehistory.org/CAD/index.php