This page is about an engine. For the Hiro Type 91 flying boat, see Hiro H4H
The Hiro Type 91, (full designation Hiro Type 91 520 hp water-cooled W-12), was a 12-cylinder, water-cooled, W engine developed for aircraft use by the Imperial Japanese Navy in the mid-1930s. Power was in the 450 kW (600 hp) range. Its design was inspired by the Lorraine-Dietrich 12Eb Courlis. An enlarged more powerful engine, the Hiro Type 90 600 hp water-cooled W-12 had also been developed using the Lorraine 12F Courlis as inspiration, developing 600 hp.
Specifications (Type 91 500hp-1)
- Type: 12-cylinder water-cooled W-block (3 banks of 4 cylinders) aircraft piston engine
- Bore: 135 mm
- Stroke: 160 mm
- Displacement: 27.5 L
- Cooling system: Liquid-cooled
- Power output:
- 620 PS for takeoff
- 520 hp for max continuous
- Related lists
Gunston, Bill (1986). World Encyclopedia of Aero Engines. Wellingborough: Patrick Stephens. p. 74.