Alfa Romeo built/designed a range of aircraft engines based on theBristol Jupiter andBristol Pegasus designs, designatedAlfa 125 ,Alfa 126 ,Alfa 127 ,Alfa 128 ,Alfa 129 andAlfa 131 . All these essentially similar engines were mainly fitted to Italian bombers in World War II, Alfa Romeo building around 11,000 units between 1934 and 1944[ 1]
Design and development [ edit ] Alfa Romeo adapted the Jupiter / Pegasus (which are very closely related) to metric measurements, local materials and indigenous equipment.
Alfa Romeo 131, 9-cyl radial engine. (The Italian engine designation system includes a suffix indicating major components or attributes. The most common were R forRiduttore - reduction gear and C forCompressore - compressor/supercharger, followed by a number indicating the rated altitude in hundreds of metres, two speed superchargers were indicated by a double figure such as 10/34).
Alfa Romeo Jupiter The standard 313 kW (420 hp) Jupiter engine built under licence from theBristol Aeroplane Company . Alfa 125 R.C.10 rated at 1,000 m (3,300 ft) Alfa 125 R.C.35 1934 — 485 kW (650 hp) rated at 3,500 m (11,500 ft) Alfa 126 R.C.10 1935 — Civilian version of 126 R.C.34 559–597 kW (750–801 hp) rated at 1,000 m (3,300 ft) Alfa 126 R.C.32 rated at 3,200 m (10,500 ft) Alfa 126 R.C.34 1935 — 507–582 kW (680–780 hp) rated at 3,400 m (11,200 ft) Alfa 127 R.C.50 rated at 5,000 m (16,000 ft) Alfa 127 R.C.55 1937 — 560 kW (750 hp) rated at 5,500 m (18,000 ft) Alfa 128 R.C.18 641–717 kW (860–962 hp) rated at 1,800 m (5,900 ft) Alfa 128 R.C.21 1938 — 708 kW (949 hp) rated at 2,100 m (6,900 ft) Alfa 129 R.C.32 rated at 3,200 m (10,500 ft) Alfa 131 R.C.14/50 1943 — Two speed supercharger, rated at 1,400 m (4,600 ft) in low gear and 5,000 m (16,000 ft) in high gear. [ edit ] Data from Aircraft Engines of the World 1945[ 6] [ 7]
General characteristics Type: 9-cylinder air-cooled radial engineBore :Stroke :Displacement :Length: 1,329 mm (52.3 in)Diameter: 1,400 mm (55.1 in)Dry weight :Frontal Area: 1.54 m2 (16.6 sq ft)
Components Valvetrain :Supercharger :Fuel system: 1 x Mona-Hobson AVT85MC updraught carburettor with automatic boost controlFuel type: 87 octane Oil system: 551.6 kPa (80 psi),dry sump .Cooling system: Air-cooledReduction gear :Starter: Garelli compressed air starterIgnition: 2 x Marelli MF9 magnetos, 2 x spark plugs per cylinder, fed by a shielded harness.
Performance Power output: Take-off: 708 kW (950 hp) at 2,300 rpm with 1,000 mm (39.37 in) Hg boostMilitary: 641 kW (860 hp) at 2,300 rpm at 2,100 m (6,900 ft)Cruising: 492 kW (660 hp) at 1,800 rpm at 2,500 m (8,200 ft)Specific power :Compression ratio :Specific fuel consumption :Oil consumption: 0.0078 kg/kW/hr (0.013 lb/hp/hr)Power-to-weight ratio :Comparable engines
Related lists
Notes
Bibliography
Wilkinson, Paul H. (1945).Aircraft engines of the World 1945 (2nd ed.). New York: Paul H. Wilkinson. pp. 288– 289. Archivio Storico Alfa Romeo - Volume II. Torino, November 1998
