| Ha5 | |
|---|---|
| Type | 14-cylinder, air-cooled, two-row radial piston engine |
| National origin | Japan |
| Manufacturer | Nakajima Aircraft Company |
| Major applications | Mitsubishi Ki-21 Mitsubishi Ki-30 Mitsubishi Ki-57 Nakajima Ki-49 (Ha-41/Ha-109) Nakajima Ki-44 (Ha-41/Ha109) |
| Developed into | Nakajima Ha219 |
The Nakajima Ha5 is a twin row, 14 cylinder air-cooled radial aircraft engine built by the Japanese Nakajima Aircraft Company. The engine was a development of earlier single-row Japanese engines, the Kotobuki and Hikari, which had combined features of the Bristol Jupiter and Pratt & Whitney R-1340 Wasp designs.
First introduced in a 1,000 PS prototype in 1933, about 7,000 civilian and 5,500 military Ha-5's were built during World War II. The Ha-5 had separate cam-discs for the front and rear rows of cylinders like American designs, rather than using a single, front-mounted cam-disc with long and short pushrods to operate both rows of cylinder valves.
The Ha-5 was a twin-row development of the Nakajima Hikari, which was itself a development of the Nakajima Kotobuki. It spawned several improved variants, namely the Ha-41, with a single stage supercharger, and the Ha-109, which featured a two-speed, single stage supercharger. The later Ha-219 was based on the same cylinder design, but was increased in size to 18 cylinders.