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.
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 (1,200 kW; 1,600 PS) R-2600-3 was originally intended for the C-46 Commando (being fitted to the prototype CW-20A) and was also the original engine choice for the F6F Hellcat; a running change (one which would not stop production) for the CW-20A, and one in late April 1942 for the second XF6F-1, led to the adoption of the 2,000 hp (1,500 kW; 2,000 PS) Pratt & Whitney R-2800 in its place for both designs. The Twin Cyclone went on to power several important American-designed World War II aircraft, including the A-20 Havoc, B-25 Mitchell, TBF Avenger, SB2C Helldiver, and PBM Mariner.
Over 50,000 R-2600s were built at plants in Paterson, New Jersey, and Cincinnati, Ohio.
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)Boeing 314 ClipperBrewster SB2A BuccaneerCurtiss SB2C HelldiverDouglas A-20 HavocDouglas B-23 DragonGrumman TBF AvengerLioré et Olivier LeO 451Martin BaltimoreMartin PBM MarinerMiles MonitorNorth American B-25 MitchellVultee A-31 VengeanceData from Jane's.
Type: 14-cylinder supercharged air-cooled two-row radial engineBore: 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)Valvetrain: Two pushrod-actuated valves per cylinder with sodium-cooled exhaust valveSupercharger: 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 speedFuel system: Stromberg PR48A downdraft carburetor with automatic mixture controlOil system: Dry sump with one pressure pump and two scavenge pumpsCooling system: Air-cooledPower output:
1,750 hp (1,305 kW) at 2,600 rpm at 3,200 ft (975 m) military power1,450 hp (1,080 kW) at 2,600 rpm at 15,000 ft (4,575 m) military powerSpecific power: 0.67 hp/in³ (30.6 kW/L)Compression ratio: 6.9:1Power-to-weight ratio: 0.86 hp/lb (1.40 kW/kg)
