Isotta Fraschini produced a long series of engines with the name Asso (Ace, in English). The Asso XI R.C. was an upright, liquid-cooled V-12 engine with maximum power output in the range 670–725 kW (898–972 hp) depending on the degree of supercharging. There were two variants, differing only in their supercharger speed: the R.C.40 ran at a little over 10 times the crankshaft speed and enabled the engine to maintain a rated power of 623 kW (835 hp) to an altitude of 4,000 m (13,000 ft) whereas the R.2C.15 held 655 kW (878 hp) to 1,500 m (4,900 ft) with a supercharger gearing of 7.[1]
All variants of the R.C.40 had much in common with construction of the earlier Asso 750 R.C., though they had two, rather than three, banks of 6 cylinders and 4 rather than 2 valves per cylinder. Cylinder barrels were machined from carbon steel with flat-topped heads and valve seats. Each barrel had a separate sheet steel water jacket. Cast aluminium head blocks were bolted to each of the two banks of 6 cylinders, providing valve ports, guides, coolant passages and camshaft supports. The pistons were also aluminium castings. The crankshaft was a 6-throw design with 8 plain bearings and a double row ball thrust bearing between the front two. The connecting rods had bronze bush little ends and white metal big ends. The crankcase was cast in two parts, the upper one with the housings for the crankshaft bearings.[1]
Variantsedit
Asso XI R
(R - Riduttore - reduction gear)
Asso XI R.C.
(C - Compressore - supercharged)
Asso XI R.C.15
Supercharger speed 75/7 times crankshaft; rated power at 1,500 m (4,900 ft).
Asso XI R.2C.15
(2C - second supercharger gearing) Supercharger speed 7 times crankshaft; rated power at 1,500 m (4,900 ft).
Asso XI R.2C.16
(2C - second supercharger gearing) Supercharger speed 7 times crankshaft; rated power at 1,600 m (5,200 ft).
Asso XI R.C.40
Supercharger speed 75/7 times crankshaft; rated power at 4,000 m (13,000 ft).
Valvetrain: two intake and two exhaust valves per cylinder, driven via cams and T-shaped tappets from inlet and exhaust pairs of overhead camshafts geared together, one for each bank of six cylinders, each pair driven by its own shaft connected indirectly to the crankshaftbevel gear.
Supercharger: single speed, single stage centrifugal, running at 10.714 times crankshaft speed.
Fuel system: four Isotta Fraschini L.70C updraft carburreters, two for each bank of six cylinders.
Oil system:dry sump with single pressure and scavenge pump shaft driven off crankshaft bevel gear.
Cooling system: water-cooled, pump shaft driven off crankshaft bevel gear.
^Calculating from the bore and stroke given in the engine specifications results in a displacement different to that provided by the referenced source, that is:
Displacement: 32.14 L (1,961 cu in)
Referencesedit
Wikimedia Commons has media related to Isotta Fraschini Asso XI.
^ abcGrey, C.G. (1972). Jane's All the World's Aircraft 1938. London: David & Charles. p. 72d. ISBN0-7153-5734-4.
January 01, 1970
isotta, fraschini, asso, asso, family, water, cooled, supercharged, piston, aeroengines, produced, 1930s, italian, manufacturer, isotta, fraschini, fitted, number, aircraft, types, built, cant, caproni, others, asso, type, water, cooled, piston, aircraft, engi. The Asso XI was a family of water cooled supercharged V12 piston aeroengines produced in the 1930s by Italian manufacturer Isotta Fraschini and fitted on a number of aircraft types built by CANT Caproni and others Asso XI Type V 12 water cooled piston aircraft engine National origin Italy Manufacturer Isotta Fraschini Milan First run early 1930s Major applications CANT Z 501 CANT Z 1007 Contents 1 Design and development 2 Variants 3 Applications 4 Specifications R C 40 4 1 General characteristics 4 2 Components 4 3 Performance 5 See also 6 Note 7 ReferencesDesign and development editIsotta Fraschini produced a long series of engines with the name Asso Ace in English The Asso XI R C was an upright liquid cooled V 12 engine with maximum power output in the range 670 725 kW 898 972 hp depending on the degree of supercharging There were two variants differing only in their supercharger speed the R C 40 ran at a little over 10 times the crankshaft speed and enabled the engine to maintain a rated power of 623 kW 835 hp to an altitude of 4 000 m 13 000 ft whereas the R 2C 15 held 655 kW 878 hp to 1 500 m 4 900 ft with a supercharger gearing of 7 1 All variants of the R C 40 had much in common with construction of the earlier Asso 750 R C though they had two rather than three banks of 6 cylinders and 4 rather than 2 valves per cylinder Cylinder barrels were machined from carbon steel with flat topped heads and valve seats Each barrel had a separate sheet steel water jacket Cast aluminium head blocks were bolted to each of the two banks of 6 cylinders providing valve ports guides coolant passages and camshaft supports The pistons were also aluminium castings The crankshaft was a 6 throw design with 8 plain bearings and a double row ball thrust bearing between the front two The connecting rods had bronze bush little ends and white metal big ends The crankcase was cast in two parts the upper one with the housings for the crankshaft bearings 1 Variants editAsso XI R R Riduttore reduction gear Asso XI R C C Compressore supercharged Asso XI R C 15 Supercharger speed 75 7 times crankshaft rated power at 1 500 m 4 900 ft Asso XI R 2C 15 2C second supercharger gearing Supercharger speed 7 times crankshaft rated power at 1 500 m 4 900 ft Asso XI R 2C 16 2C second supercharger gearing Supercharger speed 7 times crankshaft rated power at 1 600 m 5 200 ft Asso XI R C 40 Supercharger speed 75 7 times crankshaft rated power at 4 000 m 13 000 ft L 121 R C 40 A version of the Asso XI 671 kW 900 hp A 120 R C 40 Inverted version of the L 121Applications editCANT Z 501 CANT Z 505 CANT Z 508 CANT Z 1007 CANT Z 1011 Caproni Ca 124 idro Caproni Ca 134 Caproni Ca 135 Caproni Ca 405 Caproni Campini N 1 IMAM Ro 45 Piaggio P 32 Piaggio P 50 SAI Ambrosini S S 4 Savoia Marchetti SM 79 originally Specifications R C 40 editData from Jane s All the World s Aircraft 1938 1 General characteristics Type 12 cylinder supercharged water cooled 60 V 12 piston aircraft engine Bore 146 mm 5 75 in Stroke 160 mm 6 30 in Displacement 32 65 L 1 992 cu in Notes 1 Length 2 128 mm 83 78 in Width 834 mm 32 83 in Height 1 106 mm 43 54 in Dry weight 594 kg 1 310 lb Components Valvetrain two intake and two exhaust valves per cylinder driven via cams and T shaped tappets from inlet and exhaust pairs of overhead camshafts geared together one for each bank of six cylinders each pair driven by its own shaft connected indirectly to the crankshaft bevel gear Supercharger single speed single stage centrifugal running at 10 714 times crankshaft speed Fuel system four Isotta Fraschini L 70C updraft carburreters two for each bank of six cylinders Oil system dry sump with single pressure and scavenge pump shaft driven off crankshaft bevel gear Cooling system water cooled pump shaft driven off crankshaft bevel gear Reduction gear 0 743 or 0 512 compressed air starter Performance Power output rated power 623 kW 835 hp at 2 250 rpm at 4 000 m 13 000 ft take off power 596 kW 799 hp at 2 250 rpm Specific power 19 1 kW L 0 42 hp cu in at rated power Compression ratio 6 4 1 Fuel consumption 194 kg h 430 lb h at rated power Specific fuel consumption 0 312 kg kWh 0 513 lb hp h Oil consumption 0 08 kg kWh 0 13 lb hp h cruise Power to weight ratio 1 05 kW kg 0 64 hp lb See also editRelated lists List of aircraft enginesNote edit Calculating from the bore and stroke given in the engine specifications results in a displacement different to that provided by the referenced source that is Displacement 32 14 L 1 961 cu in References edit nbsp Wikimedia Commons has media related to Isotta Fraschini Asso XI a b c Grey C G 1972 Jane s All the World s Aircraft 1938 London David amp Charles p 72d ISBN 0 7153 5734 4 Retrieved from https en wikipedia org w index php title Isotta Fraschini Asso XI amp oldid 1160060109, wikipedia, wiki, book, books, library,
