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. Isotta Fraschini also produced a version of the 14K called the K.14.
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.
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
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.l00
P.XI R.C.100/2v
(geared, rated altitude 10,000 m (33,000 ft))
Breda Ba.65
Breda Ba.88
CANT Z.1007
Caproni Ca.135
Caproni Ca.161
Reggiane Re 2000
Saab 17C
Savoia-Marchetti SM.79-II
Savoia-Marchetti SM.84
Data from Italian Civil & Military Aircraft 1930-1945 and Aircraft Engines of the World 1945.
Type: 14-cylinder radial engine
Bore: 146 mm (5.748 in)
Stroke: 165 mm (6.496 in)
Displacement: 38.673 l (2,360.0 cu in)
Length: 1,700 mm (66.93 in)
Diameter: 1,328 mm (52.28 in)
Dry weight: 650 kg (1,433 lb)
Frontal Area: 1.39 m2 (15.0 sq ft)
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 482.6 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.
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)
