Franklin O-400

The Franklin O-400 (company designation 8AC) was an American air-cooled aircraft engine of the 1940s. The engine was of eight-cylinder, horizontally-opposed layout and displaced 397 cuin. The power output was 235 hp.

Variants

 * 8AC-398:200 hp at 2,600 rpm.
 * 8ACG-398:235 hp at 3,500 rpm. The 8ACG-398 was unusual in using a reduction gearing for take-off and direct drive for cruising.