The Piaggio P.IX, or Piaggio Stella P.IX, was an Italian nine-cylinder radial aircraft engine produced by Rinaldo Piaggio S.p.A. Based on the Gnome-Rhône 9K, the engine was rated at 600 hp (447 kW). Production was used to power a number of other aircraft developed in Italy. The main users were the Savoia-Marchetti SM.81 transport and the IMAM Ro.37bis, the main reconnaissance aircraft in the Regia Aeronautica during the Second Italo-Ethiopian War, Spanish Civil War and Second World War, but the engine was also used by other designs, including the prototype Savoia-Marchetti SM.79.

Design and development

Piaggio acquired a license from Gnome et Rhône in 1925 for their engines derived from the Bristol Jupiter and, in 1933, brought out a developed version, created under the direction of engineer Renzo Spolti.[1] The engine had nine cylinders and was therefore named P.IX. It was one of a range of Piaggio radial engines named Stella, or Star, all based on the same radial design.[2]

The engine had cylinders that had steel barrels and aluminium heads. Aluminium alloy pistons were connected to a split crankshaft via articulated connecting rods. The valves were enclosed.[3] Each cylinder retained the same bore and stroke as the Gnome-Rhône 9K, 146 millimetres (5.7 in) and 165 mm (6.5 in) respectively.[1] However, it was more powerful and was rated at 600 horsepower (447 kW) when fitted with a supercharger.[4]

The engine was used to power aircraft that served during the Second Italo-Ethiopian War, Spanish Civil War and Second World War, including one hundred and forty Savoia-Marchetti SM.81s, a Regia Aeronautica transport, and the majority of the production of the IMAM Ro.37bis reconnaissance aircraft. Most had retired by 1943.[5][6]

Variants

P.IX R.
Normally aspirated and geared.[2]
P.IX R.C.
Supercharged and geared.[2]
P.IX R.C.10
Supercharged and geared, rated at 1,000 m (3,300 ft).[7]
P.IX R.C.40
Supercharged and geared, rated at 4,000 m (13,000 ft).[3]

Applications

Specifications (R.C.40)

Data from Piaggio, 1939[4]

General characteristics

  • Type: 9-cylinder, single row, air cooled radial engine
  • Bore: 146 mm (5.7 in)
  • Stroke: 165 mm (6.5 in)
  • Displacement: 24.9 L (1,519 in3)
  • Length: 1,050 mm (41 in)
  • Diameter: 1,408 mm (55.4 in)
  • Dry weight: 430 kg (950 lb)

Components

Performance

  • Power output:
    • Take-off: 610 hp (455 kW) at 2100 rpm
    • Cruise: 600 hp (447 kW) at 2100 rpm at 4,000 m (13,123 ft)
  • Compression ratio: 6.0:1

See also

Related development

Comparable engines

Related lists

References

Citations

  1. ^ a b Angle 1939, p. 584.
  2. ^ a b c Gunston 1986, p. 125.
  3. ^ a b Angle 1941, p. 143.
  4. ^ a b S.A. Piaggio e.C. 1939.
  5. ^ a b Passingham 1977, p. 182.
  6. ^ a b Thompson 1963, p. 199.
  7. ^ a b Abate & Alegi 1992, p. 245.
  8. ^ Thompson 1963, p. 55.
  9. ^ Thompson 1963, p. 62.
  10. ^ Abate & Alegi 1992, p. 244.
  11. ^ a b "AP.1". Airwar. Retrieved 3 March 2020.
  12. ^ Green & Swanborough 1994, p. 108.
  13. ^ Fitzsimmons 1971, p. 2217.
  14. ^ Thompson 1963, p. 222.
  15. ^ Thompson 1963, p. 220.
  16. ^ Thompson 1963, p. 258.
  17. ^ Thompson 1963, p. 260.

Bibliography

  • Abate, Rosario; Alegi, Gregory; Apostollo, Giorgio (1992). Aeroplani Caproni: Gianni Caproni and his aircraft, 1910-1983. Trento: Associazione Museo dell'Aeronautica G. Caproni. OCLC 237798156.
  • Fitzsimmons, Barnard (1971). The Illustrated Encyclopedia of 20th Century Weapons and Warfare. Vol. 20. New York: Columbia House. OCLC 8842839.
  • Angle, Glenn Dale (1939). Aerosphere. New York: Aircraft Publications.
  • Angle, Glenn Dale (1941). Modern Aircraft Engines. New York City: Aircraft Publications. OCLC 658901703.
  • Gunston, Bill (1986). World Encyclopedia of Aero Engines. London: Guild Publishing. ISBN 978-1-85260-509-4.
  • Passingham, Malcolm (May 1977). "Savoia-Marchetti SM81". Aircraft Illustrated. 10 (5): 182–187.
  • S.A. Piaggio e.C. (1939). Instruzione per l'uso del motore P IX R C 40. Rome: Ministero dell’Aeronautica.
  • Green, William; Swanborough, Gordon (1994). The Complete Book of Fighters: An Illustrated Encyclopedia of Every Fighter Aircraft Built and Flown. New York: SMITHMARK Publishers. ISBN 0-8317-3939-8.
  • Thompson, Jonathon W. (1963). Italian Civil and Military Aircraft 1930–1945. USA: Aero Publishers Inc. ISBN 0-8168-6500-0.
Allikas: https://en.wikipedia.org/wiki/Piaggio_Stella_P.IX
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