Fiat A.80

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The Fiat A.80 RC.41 "Nembo" (Eng. "Nimbus") was an air-cooled 18-cylinder double radial engine , which was produced by the Italian Fiat Aviazione in the 1930s and in several aircraft from the prewar period to the end of the Second World War was used.

development

The Fiat A.80 engine was developed by Tranquillo Zerbi and Antonio Fessia in 1935 at the same time as the Fiat A.74 . Both types were conceptually derived from US engines for which Fiat had acquired manufacturing licenses. These were the 9-cylinder Pratt & Whitney R-1690 radial engine , which was further developed into the A.80, and the 14-cylinder double radial engine R-1830 , from which the A.74 emerged. The design of the initial constructions has been changed significantly, both to simplify production and to be able to use available materials.

The A.80 was designed for use in bomb and transport aircraft as well as for civilian use, while the smaller diameter A.74 was designed for use in fighter aircraft .

The A.80 engine was approved for production on November 10, 1937, after having passed the test, after having undergone the usual 150-hour test runs on the test bench. Under the operational conditions during the war, only fuels of lower quality were available, which caused the engine to suffer a lot despite numerous changes during production and which made it less reliable than its "little brother". The A.80 had a bad reputation among Italian pilots - strangely enough, there were no complaints from pilots who flew Fiat BR.20 bombers in the Japanese Imperial Army during the Second Sino-Japanese War . On the other hand, the engine received praise for the easy accessibility of its engine mechanics during maintenance work.

Technical specifications

A.80 RC.41

  • Type: Double radial engine 9 × 2 = 18 cylinders, air-cooled
  • Charging: radial loader with a maximum compression ratio of 1.61: 1
  • Bore: 140 mm
  • Stroke: 165 mm
  • Displacement: 45.720 liters
  • Length: 1508 mm
  • Diameter: 1335 mm
  • Compression ratio: 6.7: 1
  • Dry matter: 750 kg
  • Take-off power: 1030 hp (785 kW ) at 2200 rpm
  • Nominal power: 885 PS near the ground / 1000 PS at 2100 rpm at 4100 m altitude at 0.98 bar boost pressure
  • Maximum power: 1100 hp at an altitude of 4100 m
  • Full pressure altitude: 4100 m
  • Fuel: 87 octane aviation fuel
  • Specific fuel consumption: 270 g / hp / h at top speed, 220–230 g / hp / h at 6/10 of maximum power

Versions

  • A.80 RC.41 - major version:
    • Close-fitting cooling fins of the cylinders, two valves per cylinder in an OHV arrangement , exhaust valves with sodium filling, air baffles between the cylinders for optimal cooling air flow.
    • Preheater for sucked in fuel-air mixture
    • Propeller gear : planetary gear with bevel gear reduction of 0.625: 1
    • automatic adjustment of the propeller pitch during flight
    • Full pressure height 4100 m
  • A.80 RC.20 - smaller version:
    • Takeoff power of 1200 hp
    • Compression ratio 7: 1
    • Empty weight 742 kg
    • Full pressure height 2100 m

The total number of engines produced in both versions is around 2000 copies.

Aircraft with A.80

swell

  • Bill Gunston: World Encyclopaedia of Aero Engines. Patrick Stephens, Wellingborough 1986, p. 56.
  • Aerofan: rivista di storia aeronautica. No. 4 Oct - Dec 1978, Apostolo editore.
  • Paolo Ragazzi: The Power of Aircraft Engines at Altitude. 1938, p. 3.

Web links

Commons : Fiat A.80  - Collection of pictures, videos and audio files