title: Franklin O-300
text: # 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
  