Pratt & Whitney R-2180-E Twin Wasp E

The Pratt & Whitney R-2180-E Twin Wasp E was a radial aircraft engine developed in the United States by Pratt & Whitney. It had fourteen cylinders in two rows of seven cylinders each. Its only production application was on the post-World War II Saab 90 Scandia airliner.

R-2180-E Twin Wasp E
SAAB Scandia SAS Heathrow 1953.jpg
A Saab Scandia powered by two P&W R-2180 Twin Wasp E engines
Type Radial engine
National origin United States
Manufacturer Pratt & Whitney
First run 1945[citation needed]
Major applications Saab 90 Scandia
Developed from Pratt & Whitney R-2800
Pratt & Whitney R-4360

Design and developmentEdit

The R-2180-E is effectively a fourteen-cylinder simplification of the twenty-eight cylinder R-4360 Wasp Major engine, basically half of an R-4360 - its cylinders are the same size and displacement as those of the Wasp Major (of course, it can also be viewed as a 14 cylinder version of the eighteen cylinder R-2800 Double Wasp, which was the first engine to use the 5.75"x6" cylinder used by all three types. The R-4360 was an R-2800 cut down to 7 cylinders per bank and stacked in 4 rows, and the R-2180 is an R-2800 cut down to seven cylinders per bank and stacked in two rows...or an R-4360 cut in half). This is not to say that designing a classic 14 cylinder version of the new engine family required them to first build a 28 cylinder monster and then cut it in half; that is just a convenient way of visualizing the engine. A classic 14 cylinder version of the new engine was certainly proposed as a modest upgrade of the R-1830 even as they were introducing the new 18 cylinder R-2800, long before any serious work went into the radical new approach of stacking four rows of cylinders, which had long been considered impossible due to cooling issues, and when they decided to attempt the 4-row type, they used the plans for the 7 cylinder type banks, due to the impossibility of cooling multiple banks of nine, However, due to the excellent service of the R-1830 (and R-2000, to a lesser degree) and the more pressing need for maximum-power engines for the new types of high performance/heavy weight aircraft, the eighteen cylinder and even more radical 28 cylinder types saw service before the more conventional R-2180. More simply put, the R-2180 is not dependent on the R-4360 in any way for its existence, and would have been designed with or without that engine. [1]

The R-2180-E Twin Wasp E was available in a "power-egg" installation certificated in 1945 for use as an engine upgrade for the Douglas DC-4.[2]


Specifications (R-2180-E1)Edit

Data from[citation needed]

General characteristics

  • Type: 14-cylinder, supercharged, air-cooled, twin-row radial engine
  • Bore: 5.75 in. (146 mm)
  • Stroke: 6.00 in. (152 mm)
  • Displacement: 2,181 in³ (35.7 L)
  • Length: 76.20 in (1.94 m)
  • Diameter: 54 in (1.37 m)
  • Dry weight: 1,870 dry (850 kg)


  • Fuel system: Stromberg AR-48C1
  • Fuel type: 100/130 octane
  • Cooling system: Air-cooled


See alsoEdit

Related development

Related lists


  1. ^ "World Encyclopedia of Aero Engines - 5th edition" by Bill Gunston, Sutton Publishing, 2006, P.164
  2. ^ "World Encyclopedia of Aero Engines - 5th edition" by Bill Gunston, Sutton Publishing, 2006, P.164
  3. ^ Harding, Stephen (1997). U.S. Army Aircraft Since 1947. Atglen, PA, USA: Schiffer Publishing Ltd. pp. 202. ISBN 076430190X. LCCN 96-69996.
  • Gunston, Bill (2006). World Encyclopedia of Aero Engines, 5th Edition. Phoenix Mill, Gloucestershire, England, UK: Sutton Publishing Limited. ISBN 0-7509-4479-X.

External linksEdit