// Workers AI · dad joke modeWhat did the Franklin O-225 engine say? I'm exhausted.

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

• Cessna 160
• Bendix 51
• Bendix 52
• Bendix 55
• Dansaire Coupe
• Eshelman Winglet
• Government Workshops Triciclo-Experimental

Specifications (4A4-100)

Data from

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

See also

Comparable engines

• Lycoming O-235

Related lists

• List of aircraft engines

References

Notes

Bibliography

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