The Pratt & Whitney R-1535 Twin Wasp Junior was an engine used in American aircraft in the 1930s. The engine was introduced in 1932 as a 14-cylinder version of the 9-cylinder R-985. It was a two-row, air-cooled radial design. Displacement was 1,535 cu in (25.2 L); bore and stroke were both 5+3⁄16 in (132 mm).

This article includes a list of general references, but it lacks sufficient corresponding inline citations. (April 2018)

Quick Facts R-1535 Twin Wasp Junior, Type ...

R-1535 Twin Wasp Junior
Pratt & Whitney Twin Wasp Junior, at the National Museum of Naval Aviation, Pensacola, Florida
Type	Radial engine
National origin	United States
Manufacturer	Pratt & Whitney
First run	1932

Close

• R-1535-11 - 750 hp (560 kW)
• R-1535-13 - 750 hp (560 kW), 825 hp (615 kW)
• R-1535-44 - 625 hp (466 kW)
• R-1535-72 - 650 hp (480 kW)
• R-1535-94 - 825 hp (615 kW)
• R-1535-96 - 825 hp (615 kW)
• R-1535-98 - 700 hp (520 kW)
• R-1535-SB4-G - 825 hp (615 kW)

• There is a R-1535-96 on display at the New England Air Museum, Bradley International Airport, Windsor Locks, CT.^[1]
• There is an R-1535 on display at the San Diego Air and Space Museum.^{[citation needed]}

Data from ^[2]

• Pratt & Whitney Wasp series

Related development

• Pratt & Whitney R-985 Wasp Junior
• Pratt & Whitney R-1340 Wasp
• Pratt & Whitney R-1830 Twin Wasp
• Pratt & Whitney R-2800 Double Wasp
• Pratt & Whitney R-4360 Wasp Major

Comparable engines

• Bristol Taurus

Related lists

• List of aircraft engines