Hiro Type 91
The Hiro Type 91,, 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 range. Its design was derived from the Napier Lion. An enlarged more powerful engine, the Hiro Type 90 600 hp water-cooled W-12 had also been developed, producing 600 hp.Applications
