Franklin O-225

O-225/4A/4A4
Type	Piston aircraft engine
National origin	United States
Manufacturer	Franklin Engine Company
First run	1945

The Franklin O-225 (company designation 4A/4A4) was an American air-cooled aircraft engine that first ran in the mid-1940s. The engine was of four-cylinder, horizontally-opposed layout and displaced 225 cu in (4 L). The power output was between 75 hp (56 kW) and 125 hp (93 kW) depending on the version.

Variants

4A4-75: 75 hp (56 kW) at 1,950 rpm

4A4-85: 85 hp (63 kW) at 2,200 rpm

4A4-100: 100 hp (75 kW) at 2,550 rpm

4A-225: 100 hp (75 kW) at 2,800 rpm

Applications

Specifications (4A4-100)

Data from ^{[citation needed]}

General characteristics

Type: 4-cylinder air-cooled horizontally opposed aircraft piston engine
Bore: 4.5 in (114.3 mm)
Stroke: 3.5 in (88.9 mm)
Displacement: 222.7 in³ (3.65 L)
Dry weight: 198 lb (90 kg)

Components

Cooling system: Air-cooled

Performance

Power output: 100 hp (75 kW) at 2,550 rpm

References

Notes

Bibliography

Gunston, Bill. (1986) World Encyclopedia of Aero Engines. Patrick Stephens: Wellingborough. p. 57