The Franklin O-540 (company designation 8AC) was an American air-cooled aircraft engine that first ran in the early-1940s. The engine was of eight-cylinder, horizontally-opposed layout and displaced 540 cu in (9 L). The power output was nominally 300 hp (224 kW).
Variants
8ACG-538 (XO-540-1)
Geared propeller drive at 0.632:1, 300 hp (224 kW) at 3,200 rpm
8ACSA-538 (XO-540-7)
Supercharged, 300 hp (224 kW)
8ACGSA-538 (XO-540-3/O-540-5)
Supercharged and geared,330 hp (246 kW) at 3,200 rpm