Pratt & Whitney R-1830 Twin Wasp
The Pratt & Whitney R-1830 Twin Wasp is an American air-cooled radial aircraft engine. It displaces 1,830 cu in (30.0 L) and its bore and stroke are both 5.5 in (140 mm). The design traces its history to 1929 experiments at Pratt & Whitney on twin-row designs. Production began in 1932 and it was widely used during the 1930s.
Pratt & Whitney R-1830 Twin Wasp
R-1830 mounted on the left wing of an ex-military Douglas C-47
RAF Dakota's Twin Wasp out for servicing
Pratt & Whitney R-1830 "Twin Wasp" (sectioned)
The radial engine is a reciprocating type internal combustion engine configuration in which the cylinders "radiate" outward from a central crankcase like the spokes of a wheel. It resembles a stylized star when viewed from the front, and is called a "star engine" in some other languages.
Radial engine in a biplane
Master rod (upright) and slaved connecting rods from a two-row, fourteen-cylinder Pratt & Whitney R-1535 Twin Wasp Junior
Continental radial, 1944
Pratt & Whitney R-1340 radial mounted in Sikorsky H-19 helicopter