SPA 6A
| 6A | |
|---|---|
.JPG)
| |
| S.P.A. 6A engine on display at the Gianni Caproni Museum of Aeronautics | |
| Type | Water-cooled Piston aero engine |
| National origin | Italy |
| Manufacturer | Società Piemontese Automobili (S.P.A.), Ansaldo, Breda, Talomona, Industrie Mecchaniche e Ferroviarie of Arezzo |
| First run | c.1916 |
| Major applications | Ansaldo SVA |
| Number built | 3,000 |
The SPA 6A is an Italian water-cooled inline six-cylinder aero engine of the World War I era. The SPA 6A is mostly known for its use in the Ansaldo SVA high speed reconnaissance aircraft.[1][2]
Design and development
[edit]The Societa Piemontese Automobili (SPA) of Turin, Italy started building aircraft engines in 1908 and prior to 1916 had built flat, vee and radial engines. In 1916 SPA began manufacturing a straight-six engine known as the 6A.[3]
The SPA 6A was designed with steel cylinders arranged in pairs with a common welded water jacket. The type made use of relatively advanced features such as aluminium pistons and a 6 degree overlap in valve timing.[3]
The engine was ordered into mass production by the Italian Military Aviation Technical Division to equip the Ansaldo SVA aircraft.[2] In addition to production by SPA, the 6A engine was manufactured by Ansaldo, Breda, Talomona and Industrie Mecchaniche e Ferroviarie of Arezzo.[3]
The Ansaldo SVA was one of the fastest aircraft of WW1 with a top speed of 230 km/h (143 mph).[4] During WW1, Anasaldo SVAs made a sensational flight over Vienna to drop propaganda leaflets. Other famous exploits of the Ansaldo SVA included a 1920 Rome-Tokyo flight and a 1919 crossing of the Andes.[2]
Around 3,000 SPA 6A engines were produced in three variants: normal, semi super-compressed and super-compressed.[2][3] Engines of this type remained in service until the 1930s.[2]
Variants
[edit]- SPA 6A Normal
- Originally rated for 150 hp (112 kW) at 1,600 rpm with a displacement of 14.6 L (891 cu in) and a weight of 240 kg (529 lb).[3] Maximum power 201 hp (150 kW).[5]
- SPA 6A Semi-Super-Compressed
- Identical to the normal 6A, but with the cylinder bore increased to 137 mm (5.39 in), and with a capacity of 15.03 L (917 cu in). Rated for 210 hp (157 kW) but could develop 235 hp (175 kW) at 1,700 rpm.[3]
- SPA 6-2-A Super-Compressed
- Displacement 16.62 L (1,014 cu in) bore increased to 140 mm (5.51 in) bore and 180 mm (7.09 in) stroke, with a weight of 270 kg (595 lb). Rated at 250 hp (186 kW) but could develop 310 hp (231 kW) at 1,850 rpm.[3]
Applications
[edit]- Ansaldo A.1 Balilla
- Ansaldo SVA
- Bartel BM.5
- Breda A.2
- Breda A.3
- Breda A.9 and A.9bis
- CANT 7ter
- Caproni Ca.66
- Gabardini G.9
- SIAI S.50
Specifications (6A Normal)
[edit]Data from Angle [3]
General characteristics
- Type: Inline six-cylinder piston engine
- Bore: 135 mm (5.31 in)
- Stroke: 170 mm (6.69 in)
- Displacement: 14.57 L (888.9 cu in)
- Dry weight: 255 kg (562 lb)
Components
- Valvetrain: SOHC, two valves per cylinder
- Fuel system: Twin Zenith carburettors or one Duplex Zenith type 55-DC carburettor
- Oil system: Dry-sump
- Cooling system: Water-cooled
- Reduction gear: Direct-drive
- Twin Marelli ignition magnetos
Performance
- Power output: 110 kW (150 hp) at 1,600 rpm (rated).[3] 150 kW (200 hp) at 1,600 rpm (maximum).[5]
- Compression ratio: 5.2:1
- Specific fuel consumption: 0.288 kg/kWh (0.473 lb/(hp⋅h))
- Oil consumption: 0.02 kg/kWh (0.033 lb/(hp⋅h))
- Power-to-weight ratio: 0.439 kW/kg (0.267 hp/lb)
See also
[edit]Comparable engines
Related lists
References
[edit]
- ^ Jane's Fighting Aircraft of World War I. London: Random House. 2001. p. 316. ISBN 1-85170-347-0.
- ^ a b c d e Caramanna, Giorgio. "The Italian Air Force Museum of Vigna di Valle and its Engine Collection". enginehistory.org. Retrieved May 13, 2023.
- ^ a b c d e f g h i Angle, Glenn D. (1921). Airplane Engine Encyclopedia. Dayton, Ohio: The Otterbein Press. pp. 462–464.
- ^ Cattaneo, Gianna (1966). The S.V.A. (Ansaldo) Scouts - Profile Publications Number 61. Surrey, UK: Profile Publications Ltd. p. 10.
- ^ a b Zampicinini, Franco (1994). La collezione "Antonio Capetti" di motori alternativi per aeromobili [The “Antonio Capetti” collection of reciprocating engines for aircraft] (in Italian). Turin, Italy: Politechnico di Torino. LCCN 95222631.