During 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 (1,141-3,324 cu in) and power outputs between 320 kW and 745 kW (430-1,000 hp).[1]
Producing 710 kW (950 hp) from 54.5 L (3,324 cu in),[2] the A.25 was the largest and most powerful in the range. 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, so the A.25 was not further developed. They concentrated their higher power development effort on radial engines instead.[3]
Operational historyedit
The only series produced types powered by the A.25 were the Fiat BR.2 and BR.3 single engine bombers. These began operating with the Regia Aeronautica in 1925. Some, used as trainers, were still in service in 1939.[4]
Valvetrain: Two overhead camshafts, driven via enclosed, inclined shafts. The cams operate two inlet and two exhaust valves per cylinder. Housed under aluminium casings.
Fuel system: Three water heated Fiat carburettors mounted between cylinder banks, one serving each bank. Four spark plugs per cylinder, supplied by two Marelli MF.12 magnetos.
Oil system: One delivery pump and two scavenge pumps, in a single unit.
^Gunston, Bill (1989). World Encyclopaedia of Aero Engines (2 ed.). Wellingborough: Patrick Stephens Ltd. p. 57. ISBN1-85260-163-9.
^ ab"OLYMPIA: some of the stands - Fiat". Flight. Vol. XXI, no. 30. 25 July 1929. pp. 773–4.
^ abGrey, C.G. (1972). Jane's All the World's Aircraft 1938. London: David & Charles. p. 69d. ISBN0715-35734-4.
^ abcThompson, Jonathan (1963). Italian Civil and Military Aircraft 1930-1945. Fallbrook, California: Aero Publishers, Inc.
^Taylor, Michael J. H. (1989). Jane's Encyclopedia of Aviation. New York: Portland House. p. 384. ISBN0-517-69186-8.
November 27, 2023
fiat, italian, water, cooled, aircraft, engine, from, 1920s, produced, used, regia, aeronautica, fifteen, years, power, their, fiat, bombers, 25type, water, cooled, 12national, origin, italymanufacturer, fiat, aviazionefirst, 1924number, built, several, hundre. The Fiat A 25 was an Italian water cooled aircraft engine from the 1920s It produced 708 kW 950 hp and was used by the Regia Aeronautica for fifteen years to power their Fiat BR 2 and BR 3 bombers A 25Type Water cooled V 12National origin ItalyManufacturer Fiat AviazioneFirst run c 1924Number built several hundred Contents 1 Design and development 2 Operational history 3 Applications 4 Specifications 4 1 General characteristics 4 2 Components 4 3 Performance 5 See also 6 ReferencesDesign and development editDuring 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 3 324 cu in and power outputs between 320 kW and 745 kW 430 1 000 hp 1 Producing 710 kW 950 hp from 54 5 L 3 324 cu in 2 the A 25 was the largest and most powerful in the range 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 so the A 25 was not further developed They concentrated their higher power development effort on radial engines instead 3 Operational history editThe only series produced types powered by the A 25 were the Fiat BR 2 and BR 3 single engine bombers These began operating with the Regia Aeronautica in 1925 Some used as trainers were still in service in 1939 4 Applications editFiat BR 2 5 Fiat BR 3 4 Fiat BR 4 4 Specifications editData 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 170 mm 5 31 in Stroke 200 mm 6 29 in Displacement 54 48 L 3 324 cu in Dry weight 841 kg 1 854 lb Components Valvetrain Two overhead camshafts driven via enclosed inclined shafts The cams operate two inlet and two exhaust valves per cylinder Housed under aluminium casings Fuel system Three water heated Fiat carburettors mounted between cylinder banks one serving each bank Four spark plugs per cylinder 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 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 708 kW 950 hp at 1 700 rpm at sea level Maximum 745 kW 1 000 hp at 1 900 rpm Compression ratio 5 25 1See also editRelated lists List of aircraft enginesReferences edit nbsp Wikimedia Commons has media related to Fiat A 25 Gunston Bill 1989 World Encyclopaedia of Aero Engines 2 ed Wellingborough Patrick Stephens Ltd p 57 ISBN 1 85260 163 9 a b OLYMPIA some of the stands Fiat Flight Vol XXI no 30 25 July 1929 pp 773 4 a b Grey C G 1972 Jane s All the World s Aircraft 1938 London David amp Charles p 69d ISBN 0715 35734 4 a b c Thompson Jonathan 1963 Italian Civil and Military Aircraft 1930 1945 Fallbrook California Aero Publishers Inc Taylor Michael J H 1989 Jane s Encyclopedia of Aviation New York Portland House p 384 ISBN 0 517 69186 8 Retrieved from https en wikipedia org w index php title Fiat A 25 amp oldid 1160056285, wikipedia, wiki, book, books, library,
