Pratt & Whitney R-4360 Wasp Major engines

The Aero Spacelines Mini Guppy is equipped with four American-made 28-cylinder four-row radial piston Pratt & Whitney R-4360 Wasp Major engines. Each engine has a displacement of 4,362.5 cu in (71.489 L) and generates 4,300 hp (3,200 kW). They are the largest-displacement aviation piston engines to be mass-produced in the United States. The engines were designed and built during the later stages of WWII, but never powered aircraft in combat. The last operators of the Mini Guppy, Erickson Air Crane, retired the aircraft in 1995 to the Tillamook Air Museum in Tillamook, Oregon, USA.