Isotta Fraschini Asso Caccia

Asso Caccia
	Side view of an Asso Caccia
Type	V-12 air-cooled aircraft piston engine
National origin	Italy
Manufacturer	Isotta Fraschini, Milan
Major applications	Fiat CR.20

The Isotta Fraschini Asso Caccia, a.k.a. Isotta Fraschini Asso-450 Caccia,^[1] was an air-cooled, supercharged V12 piston aero engine produced in the late 1920s and early 1930s by Italian manufacturer Isotta Fraschini.

Design

The Asso Caccia had a V-cylinder configuration, with cylinders made of carbon steel, equipped with cooling fins, mounted separately from each other, to which a single head per cylinder was connected. Above them, two light alloy carters, one per group of cylinders, had the function of connecting the cylinder heads and the intake ducts as well as containing, closed by a cover, the tappets and the distribution members.

The crankshaft, made of special steel, was supported by a series of 8 bearings, with the insertion in the rear position between the last two of a double bearing and thrust ball bearing, which had the task of supporting the effort of the propeller whether it is mounted in a pulling or pushing configuration.^[2]

Applications

Specifications

Data from Jane's All the World's Aircraft 1928^[1]

General characteristics

Type: V-12 air-cooled 60° direct-drive piston engine
Bore: 125 mm (4.9 in)
Stroke: 140 mm (5.5 in)
Displacement: 20.610 L (1,257.7 cu in)
Length: 1,646 mm (64.8 in)
Width: 700 mm (28 in)
Height: 840 mm (33 in)
Dry weight: 315 kg (694 lb) dry

Components

Valvetrain: 4x overhead valves per cylinder driven by an overhead camshafts and rockers
Fuel system: 4x Zenith carburetors
Fuel type: aviation gasoline
Oil system: pressure
Cooling system: air
Reduction gear: direct-drive

Performance

Power output:

450 hp (340 kW) (normal) at 2,250 rpm

500 hp (370 kW) (maximum) at 2,600 rpm

Compression ratio: 5.7:1
Specific fuel consumption: 0.506 lb/(hp⋅h) (0.308 kg/kWh)

References

^ ^a ^b Grey, C.G., ed. (1928). Jane's All the World's Aircraft 1928. London: Sampson Low, Marston & company, ltd. pp. 48d – 49d.
^ Cei, Leoniero; Fiore, Amedeo (1934). Il motorista d'aviazione (in Italian). Milano: Editore Ulrico Hoepli.

[JAWA1928-1] Grey, C.G., ed. (1928). Jane's All the World's Aircraft 1928. London: Sampson Low, Marston & company, ltd. pp. 48d – 49d.

[Cei-2] Cei, Leoniero; Fiore, Amedeo (1934). Il motorista d'aviazione (in Italian). Milano: Editore Ulrico Hoepli.

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