PlaneSpottingWorld welcomes all new members! Please gives your ideas at the Terminal.

Wright Whirlwind

From PlaneSpottingWorld, for aviation fans everywhere
File:Wright J-6.jpg
Partially-sectioned Wright J-4B at Canada Aviation Museum

The Wright Whirlwind was a family of air-cooled radial aircraft engines built by Wright Aeronautical (originally an independent company, later a division of Curtiss-Wright). The family began with 9-cylinder engines and later expanded to include 5-cylinder and 7-cylinder varieties.

History

The Whirlwind was a direct descendant of the Lawrance J-1, a 9-cylinder air-cooled radial built by the Lawrance Aero Engine Company for the U.S. Navy. The Navy was very enthusiastic about air-cooled radials and was concerned that Lawrance couldn't produce enough engines for its needs, but the larger engine makers, Wright and Curtiss, had no interest in building such engines. The Navy suggested to Wright that it purchase the Lawrance company and build the J-1 itself. For added incentive, the Navy also told Wright that they would buy no more of Wright's liquid-cooled engines or spares for them. Since the Navy's purchases were a big chunk of Wright's business, Wright was thus forced to purchase Lawrance in 1923. Further J-1 engines were built by Wright.

Wright introduced the J-3 later in 1923 to fix some flaws in the J-1. (The "J-2" designation had already been used by Lawrance for an experimental design of larger bore which never went into production.) The J-4 "Whirlwind" of 1924 was the first model in the series to carry that name, and the J-5 Whirlwind of 1925 (later designated the R-790 by the U.S. government) had a greatly improved cylinder design. All of these engines were 9-cylinder radials with 4.5-inch (114 mm) bore and 5.5-inch (140 mm) stroke.

In the J-6 Whirlwind series, Wright expanded the cylinder bore to 5.0 inches (127 mm). The first engine of this series, the 7-cylinder R-760, had fewer cylinders than the older Whirlwinds but was similar in displacement and power. Wright later followed it with the larger 9-cylinder R-975 and the smaller 5-cylinder R-540, providing a range of power levels while using the same basic design.

During the 1930s, Wright developed two Whirlwind versions, the R-1510 and R-1670, which used a 14-cylinder double-row configuration. However, these never got past the experimental stage and were only used in aircraft prototypes.

The Whirlwind was lighter and more reliable than a liquid-cooled engine of similar power, since the latter's cooling system added weight and required extra maintenance. Thanks to these advantages, Whirlwind engines were used widely and were built in large numbers; licensed copies were produced by manufacturers such as Continental Motors, Hispano-Suiza, and Shvetsov. The Whirlwind's success led to the development of other air-cooled radial engines throughout the 1920s, 1930s, and 1940s, and these gradually eclipsed most liquid-cooled aircraft engines.

The reliability of Whirlwind engines led aviators to use them for a number of record-setting distance and endurance flights. The most famous of these is Charles Lindbergh's solo transatlantic flight in May 1927 in his single-engine Ryan monoplane, Spirit of St. Louis. In June 1927, Albert Hegenberger and Lester Maitland made the first successful flight from the continental U.S. to Hawaii in the Fokker C-2 trimotor Bird of Paradise, powered by three Whirlwinds. In 1935 the brothers Al and Fred Key set a new flight endurance record of 653 hours, 34 minutes in the Curtiss Robin J-1 Ole Miss, powered by a Whirlwind R-540; the plane was refueled in flight, and a catwalk leading to the engine allowed the pilots to perform necessary maintenance.

During World War II, Continental Motors built the R-975 under license for use in Allied tanks and other armored vehicles, thousands of which used this engine. When used in a tank, the Whirlwind had a cooling fan attached to its power shaft, to provide the same cooling effect as an airplane's propeller blast.

Variants

There were a large number of Whirlwind versions; only a selection are listed here.

9-cylinder Whirlwind models, up to J-5 (R-790):

  • J-1: 200 hp (149 kW) @ 1800 RPM. Version of Lawrance J-1 built by Wright Aeronautical.
  • J-3: 211 hp (157 kW) @ 1800 RPM. Improved version of the J-1.
  • J-4: 215 hp (160 kW) @ 1800 RPM. Improvement of J-3. First to be named "Whirlwind".
  • J-4A: 215 hp (160 kW) @ 1800 RPM. Modification of J-4.
  • J-4B: 215 hp (160 kW) @ 1800 RPM. Improvement of J-4A.
  • J-5 (R-790): 220 hp (164 kW) @ 2000 RPM. Complete redesign with much better performance and reliability.

5-cylinder R-540 models:

  • J-6-5 (R-540): 150 hp (112 kW) @ 1800 RPM.
  • R-540E: 175 hp (130 kW) @ 2000 RPM. Higher power from improved cylinder head.

7-cylinder R-760 models:

  • J-6-7 (R-760): 225 hp (168 kW) @ 2000 RPM.
  • R-760E: 250 hp (186 kW) @ 2000 RPM. Higher power from improved cylinder head.
  • R-760E-1: 285 hp (213 kW) @ 2100 RPM. Higher compression ratio.
  • R-760E-T: 235 hp (175 kW) @ 2000 RPM. Unsupercharged version of R-760E-1 for trainer aircraft.
  • R-760E-2: 320 hp (239 kW) @ 2200 RPM, 350 hp (261 kW) @ 2400 RPM for takeoff. Increased supercharging, slightly higher compression ratio.

9-cylinder R-975 models:

  • J-6-9 (R-975): 300 hp (224 kW) @ 2000 RPM.
  • R-975E: 330 hp (246 kW) @ 2000 RPM. Higher power from improved cylinder head.
  • R-975E-1: 365 hp (272 kW) @ 2100 RPM. Higher compression ratio.
  • R-975E-3: 420 hp (313 kW) @ 2200 RPM up to 1400 ft (427 m), 450 hp (336 kW) @ 2250 RPM for takeoff. Increased supercharging, slightly higher compression ratio.
  • R-975E-C2: 400 hp (298 kW) @ 2400 RPM. Built by Continental Motors under license. Designed for use in armored vehicles.

14-cylinder double-row experimental models:

  • R-1510: 600 hp (447 kW) @ 2100 RPM.
  • R-1670: 800 hp (597 kW) @ 2500 RPM. Larger bore of 5.25 in (133 mm).

Specifications

The J-6 Whirlwinds listed in the following table have the E cylinder head introduced in 1931, which gave slightly greater power than earlier versions of the J-6.[1]

J-5 Whirlwind (R-790)[2] J-6 Whirlwind 5, R-540E[3] J-6 Whirlwind 7, R-760E[4] J-6 Whirlwind 9, R-975E[5]
General characteristics
Type: 9-cylinder radial 5-cylinder radial 7-cylinder radial 9-cylinder radial
Bore: 4.5 in (114 mm) 5.0 in (127 mm) 5.0 in (127 mm) 5.0 in (127 mm)
Stroke: 5.5 in (140 mm) 5.5 in (140 mm) 5.5 in (140 mm) 5.5 in (140 mm)
Displacement: 788 cu in (12.91 l) 540 cu in (8.85 l) 756 cu in (12.38 l) 972 cu in (15.93 l)
Dry weight: 520 lb (236 kg) 420 lb (191 kg) 530 lb (240 kg) 635 lb (288 kg)
Components
Valvetrain: pushrod-actuated, 1 inlet and 1 exhaust valve per cylinder, salt-cooled exhaust valve stem
Supercharger: no yes, 7.05:1 impeller gear ratio yes, 7.05:1 impeller gear ratio yes, 7.8:1 impeller gear ratio
Boost pressure:
Fuel system: Stromberg NA-T4B carburetor, 1 7/16 in (36 mm) venturis Stromberg NA-R7 carburetor, 1 13/16 in (46 mm) venturi Stromberg NA-R7 or NA-R7A carburetor, 2 1/16 in (52 mm) venturi Stromberg NA-R9 or NA-R9A carburetor, 2 7/16 in (61.9 mm) venturi
Fuel type: 50 octane 65 octane 73 octane 73 octane
Ignition system: Dual Scintilla AG9D magnetos Dual Scintilla MN5-D-F magnetos Dual Scintilla MN-7-DF or SF-9R magnetos Dual Scintilla VAG-9-DF or SR-9R magnetos
Cooling system: air air air
Performance
Power output: 220 hp (164 kW) @ 2000 RPM 175 hp (130 kW) @ 2000 RPM 250 hp (186 kW) @ 2000 RPM 330 hp (246 kW) @ 2000 RPM
Specific power: 0.279 hp/cu-in (12.7 kW/l) 0.324 hp/cu-in (14.7 kW/l) 0.331 hp/cu-in (15.0 kW/l) 0.340 hp/cu-in (15.4 kW/l)
Power-to-weight ratio: 0.423 hp/lb (0.696 kW/kg) 0.417 hp/lb (0.685 kW/kg) 0.472 hp/lb (0.775 kW/kg) 0.520 hp/lb (0.854 kW/kg)
Compression ratio: 5.1:1 5.1:1 5.1:1 5.1:1

The following table lists the final, most powerful versions of the 7-cylinder and 9-cylinder Whirlwinds.

Whirlwind R-760-E2[6] Whirlwind R-975-E3[7]
General characteristics
Type: 7-cylinder air-cooled radial 9-cylinder air-cooled radial
Bore: 5.0 in (127 mm) 5.0 in (127 mm)
Stroke: 5.5 in (140 mm) 5.5 in (140 mm)
Displacement: 756 cu in (12.38 l) 972 cu in (15.93 l)
Length: 42.43 in (1078 mm) 41.20 in (1046 mm)
Diameter: 45 in (1143 mm) 45 in (1143 mm)
Dry weight: 570 lb (258 kg) 675 lb (306 kg)
Components
Valvetrain: pushrod-actuated, 1 inlet and 1 exhaust valve per cylinder, salt-cooled exhaust valve stem
Supercharger: yes, 9.17:1 impeller gear ratio yes, 10.15:1 impeller gear ratio
Boost pressure:
Fuel system: Stromberg NA-R7A carburetor, 2 1/4 in (57 mm) venturi Stromberg NA-R9A carburetor, 2 5/8 in (67 mm) venturi
Fuel type: 80 octane 80 octane
Ignition system: Dual Scintilla MN-7-DF, SF-7R, or VAG-7DF magnetos Dual Scintilla VAG-9DF or SF-9R magnetos
Cooling system: air air
Performance
Power output (continuous): 320 hp (239 kW) @ 2200 RPM at sea level 420 hp (313 kW) @ 2200 RPM at 1400 ft (427 m)
Power output (takeoff, one minute): 350 hp (261 kW) @ 2400 RPM 450 hp (336 kW) @ 2250 RPM
Specific power: 0.423 hp/cu-in (19.3 kW/l) 0.432 hp/cu-in (19.7 kW/l)
Power-to-weight ratio: 0.561 hp/lb (0.923 kW/kg) 0.622 hp/lb (1.023 kW/kg)
Compression ratio: 6.3:1 6.3:1

Applications

A complete listing of every aircraft type which used Whirlwind engines would be too long to include here. The following lists show those Whirlwind-powered aircraft that were built in substantial numbers.


J-5 (R-790) or earlier Whirlwinds: Template:Multicol

Template:Multicol-break

Template:Multicol-end


5-cylinder J-6 (R-540) Whirlwinds:


7-cylinder J-6 (R-760) Whirlwinds:


9-cylinder J-6 (R-975) Whirlwinds: Template:Multicol

Template:Multicol-break

Template:Multicol-end

Continental-built R-975:

The R-975 was used in the M2 Medium Tank, M3 Medium Tank, and M4 Sherman tank, and in other armored vehicles based on their chassis, such as the M7 Priest self-propelled gun and the Canadian Ram tank and Sexton self-propelled gun. It was also used in the M18 Hellcat tank destroyer, which had a completely different chassis.

After World War II, Continental-built R-975 engines were used in the Piasecki HUP Retriever and H-25 Army Mule helicopters.

See also

References

  1. ↑ Page 13 of "Wright Engines - Past and Present" (PDF), a 1940 Curtiss-Wright document available from the Aircraft Engine Historical Society.
  2. ↑ From the J-5 Whirlwind's FAA type certificate, Approved Type Certificate No. 13 (ATC 13), available from the FAA's Regulatory and Guidance Library.
  3. ↑ From the R-540E's FAA type certificate, ATC 23.
  4. ↑ From the R-760E's FAA type certificate, ATC 26.
  5. ↑ From the R-975E's FAA type certificate, ATC 21.
  6. ↑ From the R-760-E2's FAA type certificate, TC 155.
  7. ↑ From the R-975-E3's FAA type certificate, TC 125.
v • d • e
Lists relating to aviation
GeneralTimeline of aviation · Aircraft · Aircraft manufacturers · Aircraft engines · Aircraft engine manufacturers · Airports · Airlines
MilitaryAir forces · Aircraft weapons · Missiles · Unmanned aerial vehicles (UAVs) · Experimental aircraft
Notable incidents
and accidents		Military aviation · Airliners · General aviation · Famous aviation-related deaths
RecordsFlight airspeed record · Flight distance record · Flight altitude record · Flight endurance record · Most produced aircraft

de.wikipedia.org Wright J-5

This article is licensed under the GNU Free Documentation License.
It uses material from the Wikipedia article "Wright Whirlwind".


Retrieved from "https://plane.spottingworld.com/wiki/index.php?title=Wright_Whirlwind&oldid=10230"