Wright R-2600

The Wright R-2600 Cyclone 14 (also called Twin Cyclone) was an American radial engine developed by Curtiss-Wright and widely used in aircraft in the 1930s and 1940s.

History

In 1935, Curtiss-Wright began work on a more powerful version of their successful R-1820 Cyclone 9. The result was the R-2600 Twin Cyclone, with 14 cylinders arranged in two rows. The 1,600 hp R-2600-3 was originally intended for the C-46 Commando and was fitted to the CW-20A prototype, but a running change led to the adoption of the 2,000 hp Pratt & Whitney R-2800 in its place. The Twin Cyclone engine went on to power several key World War II production aircraft including the A-20 Havoc, B-25 Mitchell, TBF Avenger and SB2C Helldiver bombers, and the PBM Mariner flying boat.

Over 50,000 R-2600s were built at plants in Caldwell, New Jersey, and Cincinnati, Ohio.

Models/Variants

• R-2600-1 - 1,600 hp (1,194 kW)
• R-2600-3 - 1,600 hp (1,194 kW)
• R-2600-6 - 1,600 hp (1,194 kW)
• R-2600-8 - 1,700 hp (1,268 kW)
• R-2600-9 - 1,700 hp (1,268 kW)
• R-2600-12 - 1,700 hp (1,268 kW)
• R-2600-13 - 1,700 hp (1,268 kW)
• R-2600-19 - 1,600 hp (1,194 kW), 1,660 hp (1,237 kW)
• R-2600-20 - 1,700 hp (1,268 kW), 1,900 hp (1,420 kW)
• R-2600-22 - 1,900 hp (1,420 kW)
• R-2600-23 - 1,600 hp (1,194 kW)
• R-2600-29 - 1,700 hp (1,268 kW), 1,850 hp (1,380 kW)
• GR-2600-A5B - 1,500 hp (1,118 kW), 1,600 hp (1,194 kW), 1,700 hp (1,268 kW)
• GR-2600-A71 - 1,300 hp (969 kW)
• GR-2600-C14 - 1,750 hp (1,304 kW)

Applications

Wright R-2600 Cyclone being fitted to a North American B-25 Mitchell, at North American Aviation, Inglewood, California

• Boeing 314
• Brewster SB2A Buccaneer
• Curtiss SB2C Helldiver
• Douglas A-20
• Douglas B-23 Dragon
• Grumman TBF Avenger
• Lioré et Olivier LeO 451
• Martin Baltimore
• Martin Mariner
• Miles Monitor
• North American B-25 Mitchell
• Short Stirling Mk II
• Vultee A-31 Vengeance

Specifications (GR-2600-C14BB)

Data from Jane's.^[1]

General characteristics

• Type: 14-cylinder supercharged air-cooled two-row radial engine
• Bore: 6.125 in (155.6 mm)
• Stroke: 6.312 in (160.2 mm)
• Displacement: 2,603 in³ (42.7 L)
• Length: 62.06 in (1,576 mm)
• Diameter: 55 in (1,397 mm)
• Dry weight: 2,045 lb (930 kg)

Components

• Valvetrain: Two pushrod-actuated valves per cylinder with sodium-cooled exhaust valve
• Supercharger: Single-stage two-speed centrifugal type supercharger, impeller diameter 11 in (280 mm), blower ratio 7.06:1 at slow speed and 10.06:1 at high speed
• Fuel system: Stromberg PR48A downdraft carburetor with automatic mixture control
• Oil system: Dry sump with one pressure pump and two scavenge pumps
• Cooling system: Air-cooled

Performance

• Power output:
  
• 1,750 hp (1,305 kW) at 2,600 rpm at 3,200 ft (975 m) military power
• 1,450 hp (1,080 kW) at 2,600 rpm at 15,000 ft (4,575 m) military power
• Specific power: 0.67 hp/in³ (30.6 kW/L)
• Compression ratio: 6.9:1
• Power-to-weight ratio: 0.86 hp/lb (1.40 kW/kg)

See also

• Gunderson Do-All Machine - incorporates an R-2600 into an educational network of machines that is also kinetic art.

Related development

• Wright Cyclone family
• Wright R-1300 Cyclone 7
• Wright R-1820 Cyclone 9
• Wright R-3350 Cyclone 18
• Hispano-Suiza 14Aa

Comparable engines

• BMW 801
• Bristol Hercules
• Pratt & Whitney R-2800
• Fiat A.74
• Gnome-Rhône 14N
• Mitsubishi Kinsei
• Nakajima Sakae
• Shvetsov ASh-82

Related lists

• List of aircraft engines

References

Wikimedia Commons has media related to Wright R-2600.

Notes

Bibliography

• Jane's Fighting Aircraft of World War II. London. Studio Editions Ltd, 1998. ISBN 0-517-67964-7