Isotta Fraschini V.4
Isotta Fraschini V.4b on display at the Gianni Caproni Museum of Aeronautics
Type	Piston engine
Manufacturer	Isotta Fraschini
First run	1916

The Isotta Fraschini V.4 of 1916 was an Italian six-cylinder, water-cooled, in-line piston aero engine of World War I (the "V" denoted "Volo" or "flight").^[1] Its construction was fairly typical of aircraft engines of the period with six cast-iron cylinders mounted in pairs with common heads. This engine was also produced by Alfa Romeo.

Applications

• CANT 7
• Caproni Ca.3
• Caproni Ca.30
• Caproni Ca.33
• Caproni Ca.34
• Caproni Ca.35
• Caproni Ca.36
• FBA Type H
• Macchi L.1
• Macchi M.5
• Macchi M.6
• Macchi M.8
• SIAI S.8

Variants

V.4

V.4A

V.4B

V.4Bb

Engines on display

• A V.4b is on display in the Gianni Caproni Museum of Aeronautics.
• The Caproni Ca.36 on display in the National Museum of the United States Air Force is fitted with a V.4b engine.
• A V.4b is on display in the Polish Aviation Museum.

Specifications (V.4b)

Data from Jane's Fighting Aircraft of World War I (2001);^[2] Gianni Caproni Museum of Aeronautics placard description

General characteristics

• Type: Six-cylinder, water-cooled, in-line piston engine^[2]
• Bore: 130 mm (5.12 in)
• Stroke: 180 mm (7.09 in)
• Displacement: 14.3 L (874 cu in)
• Length: 1,470 mm (58 in)
• Width: 460 mm (18.11 in)
• Height: 1,020 mm (40.15 in)
• Dry weight: 264 kg (584 lb)

Components

• Valvetrain: Overhead camshaft^[2]
• Fuel system: Twin carburettors, two six spark magnetos^[2]
• Oil system: Forced feed^[2]
• Cooling system: Water; cylinders in pairs, each pair in a steel water jacket^[2]

Performance

• Power output: 142 kW (190 hp) at 1,450 rpm^[2]
• Compression ratio: 4.8