The Piaggio P.XI was an Italian 14-cylinder radial aircraft engine. The P.XI was a licensed derivative of the French Gnome-Rhône Mistral Major 14K produced in Italy.[1]

P.XI
Preserved Piaggio P.XI
Type Radial engine
Manufacturer Piaggio
Developed from Gnome-Rhône Mistral Major

Further development led to the P.XIX. This featured an increased compression ratio from 6:1 to 7:1 and an rpm increase from 2,400 to 2,600.

Variants

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P.XI
P.XIbis
P.XI R.C.15
(geared, rated altitude 1,500 m (4,900 ft))
P.XI R.C.30
(geared, rated altitude 3,000 m (9,800 ft))
P.XI R.C.40D
[2]
P.XI R.C.40S
740 kW (1,000 PS) (geared, rated altitude 4,000 m (13,000 ft)), opposite rotation to 40D.
P.XI R.C.40bis
(geared, rated altitude 4,000 m (13,000 ft))
P.XI R.2C.40
740 kW (1,000 PS), (geared, rated altitude 4,000 m (13,000 ft)), two-speed supercharger.
P.XI C.40
(direct drive, rated altitude 4,000 m (13,000 ft))
P.XI R.C.44
(geared, rated altitude 4,400 m (14,400 ft))
P.XI R.C.50
(geared, rated altitude 5,000 m (16,000 ft))
P.XI R.C.60
(geared, rated altitude 6,000 m (20,000 ft))
P.XI R.C.72
(geared, rated altitude 7,200 m (23,600 ft))
P.XI R.C.100
P.XI R.C.100/2v
(geared, rated altitude 10,000 m (33,000 ft))

Applications

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Specifications (P.XI R.C.40)

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Data from Italian Civil & Military Aircraft 1930-1945 and Aircraft Engines of the World 1945.[3][4]

General characteristics

  • Type: 14-cylinder radial engine
  • Bore: 146 mm (5.75 in)
  • Stroke: 165 mm (6.50 in)
  • Displacement: 38.6 L (2,356 cu in)
  • Length: 1,700 mm (66.9 in)
  • Diameter: 1,328 mm (52.3 in)
  • Dry weight: 650 kg (1,433 lb)
  • Frontal Area: 1.39 m2 (15.0 sq ft)

Components

  • Valvetrain: 2 x overhead valves per cylinder operated by rockers and pushrods
  • Supercharger: Centrifugal compressor, geared to 7.9:1
  • Fuel system: 1 x Piaggio T2-100 dual downdraught carburettor with automatic boost and mixture control
  • Fuel type: 87 octane
  • Oil system: Pressure fed at 483 kPa (70 psi), dry sump
  • Cooling system: Air
  • Reduction gear: Epicyclic reduction gear ratio 0.62:1
  • Starter: Garelli compressed air starter
  • Ignition: 2 x Marelli MF14 magnetos, 2 x spark plugs per cylinder fed by a shielded ignition harness.

Performance

  • Power output:
  • Take-off: 1,000 PS (735 kW) at 2,200rpm
  • Military: 1,000 PS (735 kW) at 2,200rpm at 4,000 m (13,000 ft)
  • Cruising: 1,000 PS (735 kW) at 1,800rpm at 4,000 m (13,000 ft)
  • Specific power: 19.1 kW/L (0.49 hp/cu in)
  • Compression ratio: 6.0:1
  • Specific fuel consumption: 0.292 kg/kW/hr (0.48 lb/hp/hr)
  • Oil consumption: 0.0134 kg/k/w/hr (0.022 lb/hp/hr)
  • Power-to-weight ratio: 1.15 kW/kg (0.699 hp/lb)

See also

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Related development

Related lists

References

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Notes

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  1. ^ Gunston 1989, p.110.
  2. ^ Grey, C.G.; Bridgman, Leonard (1938). Jane's All the World's Aircraft 1938. London: Sampson Low, Marston & company, ltd. :740 kW (1,000 PS) (geared, rated altitude 4,000 m (13,000 ft))
  3. ^ Thompson, Jonathan (1963). Italian Civil & Military Aircraft 1930-1945. New York: Aero Publishers Inc. ISBN 0-8168-6500-0. LCCN 63-17621.
  4. ^ Wilkinson, Paul H. (1945). Aircraft engines of the World 1945 (2nd ed.). London: Paul H. Wilkinson. pp. 306–307.

Bibliography

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  • Thompson, Jonathan (1963). Italian Civil & Military Aircraft 1930-1945. New York: Aero Publishers Inc. ISBN 0-8168-6500-0. LCCN 63-17621.
  • Wilkinson, Paul H. (1945). Aircraft engines of the World 1945 (2nd ed.). London: Paul H. Wilkinson. pp. 306–307.
  • Grey, C. G.; Bridgman, Leonard (1938). Jane's All the World's Aircraft 1938. London: Sampson Low, Marston & company, ltd.
  • Gunston, Bill. World Encyclopedia of Aero Engines. Cambridge, England. Patrick Stephens Limited, 1989. ISBN 1-85260-163-9