Summary
The Isotta Fraschini Beta was an air cooled aircraft engine produced by the Italian engineering company Isotta Fraschini in the 1940s. Isotta Fraschini derived the Beta inverted 6-cylinder in-line aircraft engine from the V-12 Gamma. The engine saw limited production for aircraft, including the Nardi FN.316 and Ambrosini SAI.7, but was generally unsatisfactory in service.
| Beta | |
|---|---|
| |
| The Ambrosini SAI.7 | |
| Type | Piston aircraft engine |
| National origin | Italy |
| Manufacturer | Isotta Fraschini |
| Developed from | Isotta Fraschini Gamma |
Design and development edit
Isotta Fraschini had developed V-12 Gamma aircraft engine, which gained some success, powering the Ambrosini SAI.107 lightweight fighter.[1] The company took essentially half of the engine and created the Beta inverted 6-cylinder in-line aircraft engine. The Beta shared the larger engine's bore and stroke. The engine had a one-piece aluminium alloy crankcase with steel and aluminium cylinders, each with a single inlet and a single exhaust valve. It had a carburettor designed by Isotta Fraschini and a single speed supercharger.[2]
The Beta was produced in small numbers and fitted to a number of Italian training aircraft, including the Nardi FN.316 used in limited quantities by the Regia Aeronautica, Aeronautica Nazionale Repubblicana and German Luftwaffe during World War II.[3] However, the engine was unsatisfactory in service, its failure leading to the cancellation of the IMAM Ro.63 STOL reconnaissance aircraft.[4]
Variants edit
- Beta R.C.10 ISZ
- 300 hp (224 kW) for take-off 270 hp (201 kW) at 1,500 m (4,921 ft).[2]
Applications edit
Specifications edit
Data from Wilkinson, 1945[2]
General characteristics
- Type: 6-cylinder air cooled inverted in-line aircraft piston engine
- Bore: 125 mm (4.9 in)
- Stroke: 130 mm (5.1 in)
- Displacement: 9.6 L (586 in3)
- Length: 1,625 mm (64.0 in)
- Width: 410 mm (16 in)
- Height: 800 mm (31 in)
- Dry weight: 225 kg (496 lb)
Components
- Valvetrain: Two valves per cylinder with overhead camshaft
- Supercharger: Single stage, 10.0:1
- Fuel type: 87 octane petrol
- Cooling system: Air-cooled
- Reduction gear: 0.79:1
Performance
- Power output:
- (Take-off) 300 hp (224 kW) at 2700 rpm
- (Normal) 270 hp (201 kW) at 2500 rpm at 4,600 m (15,100 ft)
- (Cruising) 210 hp (157 kW) at 2200 rpm at 4,600 m (15,100 ft)
- Specific power: 23.5 kW/L (0.51 hp/in³)
- Compression ratio: 6.5:1
- Fuel consumption: 320 g/(hp•h) (0.53 lb/(hp•h))
- Oil consumption: 9.3 g/(hp•h) (0.02 lb/(hp•h))
- Power-to-weight ratio: 1.00 kW/kg (0.61 hp/lb)
See also edit
Related development
Comparable engines
Related lists
References edit
Notes edit
- ^ Thompson 1963, p. 15.
- ^ a b c Wilkinson 1945, p. 297.
- ^ Arena 1996, p. 325.
- ^ "Plane Facts: Italian Liaison STOL". Air Enthusiast. Vol. 2, no. 3. 1972. p. 150.
- ^ Thompson 1963, p. 46.
- ^ Thompson 1963, p. 13.
- ^ Brotzu, Caso & Cosolo 1977, p. 68.
- ^ Stocchetti 2009.
Bibliography edit
- Arena, Nino (1996). L'Aeronautica Nazionale Repubblicana: la guerra aerea in Italia 1943-1945 (in Italian). Parma: Albertelli.
- Brotzu, Emilio; Caso, Michele; Cosolo, Gherardo Cosolo (1977). Aerei Italiani nella 2ª Guerra Mondiale Vol.11, Scuola-Collegamento (in Italian). Roma: Edizioni Bizzarri. ISBN 978-8-8859-0949-6.
- Stocchetti, Roberto (2009). "SAI Ambrosini 7, immagini, scheda e storia". Ali e Uomini (in Italian). Retrieved 8 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: P H Wilkinson.