Isotta Fraschini Gamma

Gamma
Isotta Fraschini Gamma R.C.35
Type	Air cooled V12 aircraft engine
National origin	Italy
Manufacturer	Isotta Fraschini

The Isotta Fraschini Gamma was an air cooled aircraft engine developed by the Italian engineering company Isotta Fraschini in the 1930s.

Isotta Fraschini produced the Gamma in small numbers during World War II at a rating of about 500 hp (373 kW).^[1] It formed the basis for a number of other aircraft engines produced by the company. The more powerful Delta was developed as a larger complement to the Gamma. While the Beta straight-six engine was essentially one half of the engine, the Zeta mated two Gamma engines to a common crankshaft to create an X24 engine.^[2]

In 1942, there was speculation in the UK about a powerful Italian engine called the Isotta Fraschini Gamma that produced 1,700 hp (1,268 kW) at 2200 rpm for take-off, a displacement of 55.562 L (3,391 in³), bore of 195 mm (7.7 in) and stroke of 192.5 mm (7.58 in).^[3]

Gamma R.C.15

540 hp (403 kW) at 1,500 m (4,921 ft)

Gamma R.C.35

515 hp (384 kW) at 3,500 m (11,483 ft)

• Caproni Vizzola F.5 Gamma^[4]
• Savoia-Marchetti SM.86^[5]
• Ambrosini SAI.107^[6]

Data from Pearce, 2017^[2] and Wilkinson, 1945^[7]

• Type: 12-cylinder air cooled 60° inverted V aircraft piston engine
• Bore: 125 mm (4.9 in)
• Stroke: 130 mm (5.1 in)
• Displacement: 19.1 L (1,166 in³)

• Valvetrain: Two valves per cylinder with dual overhead camshafts
• Supercharger: Single stage, 10.34:1
• Fuel type: 87 octane petrol
• Cooling system: Air-cooled

• Power output:
• (Take-off) 550 hp (410 kW) at 2200 rpm
• (Military) 580 hp (433 kW) at 2730 rpm at 4,000 m (13,000 ft)
• Compression ratio: 6.5:1

Related development

• Isotta Fraschini Beta
• Isotta Fraschini Delta
• Isotta Fraschini Zeta

Comparable engines

• Alfa Romeo 122
• Argus As 410
• de Havilland Gipsy Twelve
• Walter Sagitta

Related lists

• List of aircraft engines

Wikimedia Commons has media related to Isotta Fraschini Gamma.

• Brotzu, Emilio; Caso, Michele; Cosolo, Gherardo Cosolo (1973). Aerei Italiani nella 2ª Guerra Mondiale Vol.5, Bombardieri-Ricognitori (in Italian). Roma: Edizioni Bizzarri.
• Gunston, Bill (1998). World Encyclopedia of Aero Engines. Sparkford: P. Stephens. ISBN 1-8526-0597-9.
• Morrison, John W. (7 May 1942). "Power Units of the Future". Flight: 447–451. Retrieved 7 September 2018.
• Pearce, Willian (2017). "Isotta Fraschini Zeta X-24 Aircraft Engine". Old Machine Press. Retrieved 7 September 2018.
• Thompson, Jonathan (1963). Italian Civil and Military Aircraft, 1930-1945. Los Angeles: Aero Publishers. ISBN 1-2584-4296-5.
• Wilkinson, Paul (1945). Aircraft Engines of the World. New York: Paul Wilkinson.