Franklin O-300
# Franklin O-300

The Franklin O-300 (company designation 6AC-298) was an American air-cooled aircraft engine of the early 1940s. The engine was of six-cylinder, horizontally-opposed layout and displaced 300 cu in (5 L). The power output ranged between 130 hp (97 kW) and 175 hp (130 kW) depending on variant. The 6ACG-298 featured a geared propeller drive.

An enlarged displacement version was known as the O-315, 6A3 or 6AL-315.

## Variants

### O-300

**6AC-298-F3 (O-300-1)**


    130 hp (97 kW) at 2,600 rpm

**6ACT-298**


    150 hp (112 kW) at 3,000 rpm

**6ACT-298-J4 (O-300-3)**


    150 hp (112 kW) at 2,930 rpm

**6ACT-298-35 (O-300-11)**


    150 hp (112 kW) at 2,930 rpm

**6ACG-298-P5 (O-300-9)**


    Geared propeller drive 0.63:1, 160 hp (119 kW) at 3,200 rpm

**6ACTS-298**


    Supercharged, 160 hp (119 kW) at 3,200 rpm

**6ACTS-298-K4 (O-300-7)**


    Supercharged, 175 hp (130 kW) at 3,000 rpm

**6ACV-298**


    Vertical installation for helicopters,160 hp (119 kW) at 3,250 rpm

### O-315 (6A3)

**6AL-315**


    175 hp (130 kW)

**6ALG-315**


    175 hp (130 kW)

## Applications

### Direct drive

* Aeronautical Products A-1
* Aeronautical Products A-3
* CNNA HL-6
* Culver XPQ-9
* Culver XPQ-14, YPQ-14A, XPQ-15
* Bell 30
* Bellanca T-14
* Erco XPQ-13
* Fleetwings 33
* Hockaday Comet
* Piper PT-1
* Troy A
* Zodiac Libra-Det

### Geared drive

* Culver PQ-14 Cadet
* Republic RC-1 Thunderbolt (O-315)

### Supercharged

* Northwestern XPG-1 (Waco CG-4 twin-engine conversion)

## Specifications (6AC-298)

Data from

### General characteristics

* Type: 6-cylinder air-cooled horizontally opposed aircraft piston engine
* Bore: 4.25 in (108 mm)
* Stroke: 3.5 in (88.9 mm)
* Displacement: 297.9 in³ (4.88 L)
* Dry weight: 260 lb (118 kg)

### Components

* Cooling system: Air-cooled

### Performance

* Power output: 130 hp (97 kW) at 2,600 rpm
