Franklin O-400
# 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 cu in (6.5 L). The power output was 235 hp (175 kW).

## Variants

### 8AC-398

    200 hp (149 kW) at 2,600 rpm.

### 8ACG-398

    235 hp (175 kW) at 3,500 rpm. The 8ACG-398 was unusual in using a reduction gearing for take-off and direct drive for cruising.

## Specifications (8ACG-398)

### General characteristics

* Type: 8-cylinder air-cooled horizontally opposed aircraft piston engine
* Bore: 4.25 in (108.0 mm)
* Stroke: 3.5 in (88.9 mm)
* Displacement: 397.2 cu in (6,509 cc)

### Components

* Valvetrain: OHV
* Cooling system: Air-cooled

### Performance

* Power output: 235 hp (175.2 kW) at 2,600 rpm
