Pratt & Whitney R-1690 Hornet
| R-1690 Hornet | |
|---|---|
 
 | |
| Pratt & Whitney Hornet, at the Deutsches Museum, Munich. | |
| Type | Radial engine | 
| National origin | United States | 
| Manufacturer | Pratt & Whitney | 
| First run | June 1926 | 
| Major applications | Boeing 80  Lockheed Lodestar Sikorsky S-42 Vought O2U Corsair  | 
| Number built | 2,944 | 
| Developed into | Pratt & Whitney R-1860  BMW 132 Mitsubishi Kinsei  | 
The Pratt & Whitney R-1690 Hornet was a widely used American aircraft engine. Developed by Pratt & Whitney, 2,944 were produced from 1926 through 1942.[1] It first flew in 1927. It was a single-row, 9-cylinder air-cooled radial design. Displacement was 1,690 cubic inches (27.7 L). It was built under license in Italy as the Fiat A.59. In Germany, the BMW 132 was a developed version of this engine. The R-1860 Hornet B was an enlarged version produced from 1929.
Variants
- R-1690-3
 - 525 hp (391 kW)
 - R-1690-5
 - 525 hp (391 kW)
 - R-1690-11
 - 775 hp (578 kW)
 - R-1690-13
 - 625 hp (466 kW)
 - R-1690-S5D1G
 - 700 hp (520 kW)
 - R-1690-52
 - 750 hp (560 kW)
 - R-1690-SDG
 - R-1690-S1EG
 - 750 hp (560 kW)
 - R-1690-S2EG
 - R-1690-25
 - 850 hp (630 kW)
 - R-1690-S1C3G
 - 1,050 hp (780 kW)
 - Fiat A.59 R.
 - License built in Italy with reduction gearing.
 - Fiat A.59 R.C.
 - License built in Italy with reduction gearing and supercharger.
 - BMW Hornet
 - License production of the Hornet in Germany, independently developed as the BMW 132.
 
Applications
- Bach Air Yacht
 - Bellanca 31-40
 - Boeing 80
 - Boeing Model 95
 - Boeing Model 299
 - Burnelli UB-14
 - Douglas O-38
 - Focke-Wulf Fw 200 V1
 - Gee Bee Model R-2 (1933)
 - Gee Bee R 1/2 Super Sportster
 - Granville-Miller-de Lackner R-6H "Q.E.D."
 - Junkers Ju 52
 - Junkers Ju 86
 - Junkers W 34
 - Keystone B-3
 - Lockheed Model 14 Super Electra (L-14H)
 - Lockheed Lodestar (C-56A, C-56B, C-56C, C-56D, C-56E, C-59/Mk 1a)
 - Martin BM
 - Martin XB-14
 - Vought O2U Corsair
 - Sikorsky S-40A
 - Sikorsky S-42
 - Sikorsky S-43
 - Wedell-Williams Model 44
 
Engines on display
- There is a R-1690 on display at the New England Air Museum, Bradley International Airport, Windsor Locks, CT.[2]
 
Specifications (R-1690 S1E-G)

Data from [3]
General characteristics
- Type: Nine-cylinder single-row supercharged air-cooled radial engine
 - Bore: 6+1⁄8 in (155.6 mm)
 - Stroke: 6+3⁄8 in (161.9 mm)
 - Displacement: 1,690.5 cu in (27.7 L)
 - Length: 50.98 in (1,295 mm)
 - Diameter: 54.41 in (1,382 mm)
 - Dry weight: 1,014 lb (460 kg)
 
Components
- Valvetrain: Pushrod-actuated
 - Supercharger: Single-speed centrifugal type supercharger, 12.0:1 gear ratio
 - Fuel system: Two-barrel Stromberg carburetor
 - Fuel type: 87 octane rating gasoline
 - Cooling system: Air-cooled
 - Reduction gear: Epicyclic gearing, 2:3
 
Performance
- Power output: 
 - 789 hp (588 kW) at 2,300 rpm for takeoff
 - 740 hp (550 kW) at 2,250 rpm at 7,000 ft (2,100 m)
 - Specific power: 0.47 hp/cu in (21.39 kW/L)
 - Compression ratio: 6.0:1
 - Specific fuel consumption: 0.6 lb/(hp•h) (362 g/(kW•h))
 - Oil consumption: 0.42 oz/(hp•h) (16 g/(kW•h))
 - Power-to-weight ratio: 0.78 hp/lb (1.28 kW/kg)
 
See also
Related development
Comparable engines
Related lists
References
Notes
- ^ Pratt & Whitney - R-1690 page Archived 2008-01-26 at the Wayback Machine Retrieved: 25 October 2008
 - ^ http://neam.org/index.php?option=com_content&view=article&layout=edit&id=1129 "Pratt & Whitney R-1690 Hornet"
 - ^ Tsygulev (1939). Aviacionnye motory voennykh vozdushnykh sil inostrannykh gosudarstv (Авиационные моторы военных воздушных сил иностранных государств) (in Russian). Moscow: Gosudarstvennoe voennoe izdatelstvo Narkomata Oborony Soyuza SSR. Archived from the original on 2009-03-24.
 
Bibliography
- Gunston, Bill (2006). World Encyclopedia of Aero Engines, 5th Edition. Phoenix Mill, Gloucestershire, England, UK: Sutton Publishing Limited. ISBN 0-7509-4479-X.
 
External links
Wikimedia Commons has media related to Pratt & Whitney R-1690.
