Hiro Type 91 (engine)

Type 91
Type	W-12 water-cooled piston engine
National origin	Japan
Manufacturer	Hiro Naval Arsenal
Developed from	12Eb

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 had also been developed, producing 600 hp.

Gunston, Bill (1986). World Encyclopedia of Aero Engines. Wellingborough: Patrick Stephens. p. 74. 

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