Alfa Romeo D2

The Alfa Romeo D2 was a nine-cylinder radial engine for aircraft use produced in Italy. It was typically rated between 240-270 hp. The engine was designed by Vittorio Jano and produced 600 units between 1931-1934. This engine was also first purpose-built aircraft engine produced by Alfa Romeo, before it all Alfa engines used in airplanes were derived from engines used in cars. A supercharged derivative was produced as the D2 C.

Applications:
Breda Ba.25
Caproni Ca.101

General characteristics
Type: Nine-cylinder radial engine
Bore: 120 mm (4.724 in.)
Stroke: 135 mm (5.315 in.)
Displacement: 13.74 L (838.5 cuin)
Supercharger: 2.5:1
Power output: 270 hp
Compression ratio: 5:1