Fiat A.22
The Fiat A.22 was an Italian water-cooled aircraft engine from the 1920s. It produced 425 kW (570 hp) and powered several absolute world distance records as well as commercial passenger flights.
| A.22 | |
|---|---|
 | |
| Fiat A.22 T | |
| Type | Water-cooled V-12 |
| National origin | Italy |
| Manufacturer | Fiat Aviazione |
| First run | 1926 |
| Number built | "several hundred"[1] |
| Developed into | Fiat AS.2 |
Design and development
During the second half of the 1920s Fiat introduced several water-cooled aircraft engines, including the A.20, A.22, A24, A.25 and A.30. They were all upright V-12s with 60° between the cylinder banks; capacities ranged between 18.7 L and 54.5 L (1,141-3,326 cu in) and power outputs between 320 kW and 745 kW (430-1,000 hp).[1]
Producing 425 kW (570 hp) from 27.5 L (1,678 cu in),[2] the A.22 was towards the middle of these ranges. When Fiat were advised by the government to simplify their water-cooled product line, they focussed on the A.20, A.22 and A.30 models.[3] The A.22 was first run in 1926 and a "few hundred" were built.[1]
The A.22 was developed into the Fiat AS.2 and AS.3 Schneider Trophy race engines.[3]
Operational history
The A.22 was best known for its contribution to some world long distance record flights[2] made by the single engine landplane Savoia-Marchetti S.64, which used the specially adapted A.22 T. version. Between 31 May and 2 June 1928 this aircraft flew non-stop for 7,665 km (4,763 mi) to capture the world closed circuit distance record. The flight lasted 58 hr 34 min; the two crew, Capt. Arturo Ferrarin and Major Del Prete took turns as pilot.[4] A month later, the same crew set a new world straight-line distance record of 7,187 km (4,467 mi), flying from Italy to Brazil in 47 hr 55 min. The closed circuit record was later taken by the French but a slightly revised S.64bis recovered it for Italy with a distance of 8,187 km (5,088 mi) flown in 67 hr 13 min on 31 May-2 June 1930.[4]
The A.22R powered more conventional, airline, flights in a Savoia-Marchetti S.66 three engine flying boat operated by Ala Littoria on the Rome-Cagliari-Tripoli and Rome-Athens-Alexandria routes.[4]
Variants
From Jane's all the World's Aircraft 1938[3]
- A.22
- un-geared, compression ratio 5.5:1.[5]
- A.22 R.
- (R - Riduttori - reduction gear) Geared 0.5:1, compression ratio 5.5:1.[5]
- A.22 S.
- High compression, compression ratio 6:1.[5]
- A.22 AQ.
- (AQ - Alta Quota - high altitude) Direct drive, compression ratio 7.5:1.[5]
- A.22 AQ.R.
- (AQ.R. - Alta Quota Riduttori - high altitude geared) High altitude 0.5:1 geared engine, compression ratio 7.5:1.[5]
- A.22 T.
- Special version for Savoia-Marchetti S.64.
Specifications (A.22 R.)
Data from Flight 25 July 1929, pp. 773–4[2] and Jane's All the World's Aircraft 1938[3]
General characteristics
- Type: water-cooled 60° upright V-12
- Bore: 135 mm (5.31 in)
- Stroke: 160 mm (6.29 in)
- Displacement: 27.5 L (1,678 cu in)
- Dry weight: including propeller hub, 455 kg (1,004 lb)
Components
- Valvetrain: Two overhead camshafts, driven via enclosed, inclined shafts. The cams operate two inlet and two exhaust valves per cylinderHoused under aluminium casings.
- Fuel system: Twin water heated Fiat carburettors mounted between cylinder banks, one serving each bank. Two spark plugs per cylinder, placed horizontally and opposite each other, supplied by two Marelli MF.12 magnetos.
- Oil system: One delivery pump and two scavenge pumps, in a single unit.
- Cooling system: water, with centrifugal pump.
- Reduction gear: spur gear, lubricated via oil spout.
- Cylinders: Forged steel barrels, with closed, flat ends.
- Pistons: Aluminium alloy, two compression rings and one scraper ring above a fully floating gudgeon pin, with a second scraper ring below it.
- Crankshaft: Each six throw, seven bearings.
- Crankcase: Each an aluminium casting, split on crankshaft centre line. Bolted-on duralumin end caps.
Performance
- Power output: normal, 425 kW (570 hp) at 1,900 rpm at sea level. Maximum, 462 kW (620 hp) at 2,100 rpm.
- Compression ratio: 5.5:1
References
- Gunston, Bill (1989). World Encyclopaedia of Aero Engines (2 ed.). Wellingborough: Patrick Stephens Ltd. p. 57. ISBN 1-85260-163-9.
- "OLYMPIA: some of the stands - Fiat". Flight. Vol. XXI, no. 30. 25 July 1929. pp. 773–4.
- Grey, C.G. (1972). Jane's All the World's Aircraft 1938. London: David & Charles. pp. 68–9d. ISBN 0715-35734-4.
- Thompson, Jonathan (1963). Italian Civil and Military Aircraft 1930-1945. Fallbrook, California: Aero Publishers, Inc.
- Grey, C.G., ed. (1928). Jane's all the World's Aircraft 1928. London: Sampson Low, Marston & company, ltd. pp. 45d–47d.