The Wasp Major was Pratt & Whitney’s last big piston engine. Although four rows in the radial configuration seems a cooling problem, the Wasp Major was effectively cooled by staggering each of its rows of seven cylinders. Although reliable in flight, the engine required extensive and time consuming checks at startup and shutdown.
Beginning in 1941, the gigantic Convair B-36 strategic bomber was likely planned around this engine, which used six R-4360s along with four turbojets. The Wasp Major saw service at the end of World War II in late Boeing B-29s that were actually early B-50s, and powered the Boeing B-50 "Lucky Lady" when it made the first non-stop around the world flight from Fort Worth, Texas, in 1949.
Other principal applications were in the Douglas C-124 Globemaster and the civilian Boeing Stratocruiser, derived from the B-50.
Display Status
This object is not on display at the National Air and Space Museum. It is either on loan or in storage.
Object Details
Date
1943
Country of Origin
United States of America
Type
PROPULSION-Reciprocating & Rotary
Manufacturer
Pratt & Whitney
Physical Description
Type: Reciprocating, 28 cylinders, radial, 4-rows, air-cooled
Power rating: 2,088 kW (2,800 hp) at 2,700 rpm
Dispacement: 71.5 L (4,360 cu in.)
Bore and Stroke: 146 mm (5.8 in.) x 152 mm (6.0 in.)
Weight: 1,636 kg (3,600 lb)
Dimensions
Approximate: 167.64 x 247.65 x 145.42cm (5ft 6in. x 8ft 1 1/2in. x 4ft 9 1/4in.)
Approximate (Weight on Stand): 1873.4kg (4130lb.)
Depth 167.6 cm (66 in.), Length 247.7 cm (97.5 in.), Width 145.4 cm (57.25 in.)
Materials
HAZMAT: Cadmium Plating, Magnesium
Steel, Aluminum, Paint, Rubber, Copper, Brass, Wood
Inventory Number
A19530050000
Credit Line
Gift of Pratt & Whitney Aircraft
Data Source
National Air and Space Museum
Restrictions & Rights
Usage conditions apply
For more information, visit the Smithsonians Terms of Use.