Wright R-760

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Wright Aeronautical
Mechanic in front of an R-760 engine in a US Navy N3N, October 1942

Mechanic in front of an R-760 engine in a US Navy N3N, October 1942
Wright R-760
Production period: 1929-1945
Manufacturer: Wright Aeronautical
Developing country: United StatesUnited States United States
Working principle: Otto
Motor design: Radial engine
Cylinder: 7th
Drilling: 127 mm
Hub: 140 mm
Displacement: 12400 cm 3
Mixture preparation:
Engine charging: compressor
Cooling system: Air cooling
Power: 168 - 261 kW
Dimensions: 240-259 kg
Previous model: none
Successor: none

Wright R-760 Whirlwind is a series of air-cooled seven-cylinder star engines from the US engine manufacturer Wright Aeronautical , a Curtiss-Wright subsidiary . The engines have a displacement of 12.4 liters and outputs between 225  hp (165  kW ) and 350 hp (257 kW).

construction and development

Wright introduced the J-6 Whirlwind family in 1928 to replace the nine-cylinder R-790 series . It included models with five , seven and nine cylinders , the seven-cylinder model originally being called the J-6 Whirlwind Seven (J-6-7 for short). However, the US government chose the designation R-760, which was later adopted by Wright.

Like all models in the J-6 family, the R-760 has larger cylinders than the R-790. While maintaining the 5.5  in (139.7  mm ) stroke , the bore has been expanded from the 4.5 in (114.3 mm) of the R-790 to 5 in (127 mm). Unlike the naturally aspirated R-790, the R-760, like all J-6 engines, is supercharged .

Over time, Wright refined the R-760 and identified the different versions with letters appended. The original R-760 had an output of 225  PS (165  kW ), while the R-760E from 1931 developed 250 PS (184 kW) due to redesigned cylinder heads . Wright later added another suffix to denote various engine powers. The R-790E-1, which was built in the same year as the R-760E, had a take-off power of 300 hp (221 kW) thanks to improved compression and a higher rated speed . The R-760E-2 from 1935 even developed 350 hp (257 kW) due to increased supercharging and an even higher rated speed.

The R-760E-T (T for trainers) designed for training aircraft , on the other hand, had the high compression of the R-760E-1, but not the supercharger and thus only developed 235 hp (173 kW).

Mission history

The R-760 was a replacement for the R-790 with a similar displacement and performance. The US Navy used it as an engine for various biplanes - primarily training aircraft - such as the Consolidated NY , the Curtiss N2C Fledgling and the N3N Canary of the Naval Aircraft Factory , the latter of which are manufactured in large numbers and in most cases with one under license from engine built by the Naval Aircraft Factory. The R-760E-T was normally used for the trainer aircraft.

Many civil aircraft types, including Beechcraft , Cessna , Curtiss-Wright , Stearman , Stinson , and Waco , also used R-760s for propulsion. Mostly the supercharged R-760 models were used for this.

Around 1,400 R-760s had been built by 1945. Other examples were produced under license by foreign manufacturers such as the Brazilian Fábrica Nacional de Motores .

Versions

  • J-6-7 (R-760) : 225 hp (165 kW) at 2000 min -1
  • R-760E : 250 hp (184 kW) at 2000 min -1 , increased power due to an improved cylinder heads
  • R-760E-1 : 285 hp (210 kW) at 2100 min -1 , 300 hp (221 kW) at 2250 min -1 starting performance by increased compression
  • R-760E-2 : 320 hp (235 kW) at 2200 min -1 , 350 hp (257 kW) at 2400 min -1 starting performance through increased supercharger compressor and increased compression
  • R-T-760E : 235 hp (173 kW) at 2000 min -1 , version of the R-760E-1 without charging for training aircraft
  • R-760-2 , -4 , -8 : 235 hp (173 kW) at 2,000 min -1 , US Navy versions of the R-760E-T

application

Issued copies

Wright R 760 engines are rarely on display. An R-760-E2 is located at the Evergreen Aviation & Space Museum in McMinnville , Oregon .

Technical specifications

engine Continuous output Starting power compression Gear ratio charge compressor Octane number Dry matter
R-760E 250 hp (184 kW) at 2000 min -1 5.1: 1 7.05: 1 73 530 lb (240 kg)
R-760E-1 285 hp (210 kW) at 2100 min -1 300 hp (221 kW) at 2250 min -1 6.1: 1 7.05: 1 73 565 lb (256 kg)
R-760E-2 320 hp (235 kW) at 2200 min -1 350 hp (257 kW) at 2400 min -1 6.3: 1 9.17: 1 80 570 lb (259 kg)
R-760E-T 235 hp (173 kW) at 2000 min -1 6.1: 1 none 73 540 lb (245 kg)

See also

Web links

Commons : Wright R-760  - Collection of Images, Videos and Audio Files

Individual evidence

  1. ^ Bill Gunston: World Encyclopedia of Aero Engines . Patrick Stephens Limited, Cambridge, England 1989, ISBN 1-85260-163-9 , pp. 181 (English).
  2. ↑ a b c d e f g h i j Wright Engines - Past and Present. (pdf) Curtiss-Wright , 1940, archived from the original ; accessed on February 6, 2020 (English).
  3. ↑ a b c d e f g h i j Historical Engine Summary (Beginning 1930). (pdf) Curtiss-Wright , 1983, archived from the original ; accessed on February 6, 2020 (English).
  4. ^ Robert J. Neal: Summary of Wright Engine Shipments: 1920 to 1963 . Wright Aeronautical (English).
  5. ↑ AEHS List of engines in the museum - North America. Aircraft Engine Historical Society, accessed February 6, 2020 .