Franklin O-150

O-150/4AC
4AC-150 engine on display at the San Diego Air & Space Museum
Type	Piston aircraft engine
National origin	United States
Manufacturer	Franklin Engine Company
First run	1938

The Franklin O-150 (company designation 4AC-150) was an American air-cooled aircraft engine of the late 1930s. The engine was of four-cylinder, horizontally-opposed layout and displaced 150 cu in (2 L). The power output was nominally 40 hp (30 kW).

Applications

• Aeronca 50 Chief
• Bartlett Zephyr
• Clutton-Tabenor FRED
• Fetterman Chickadee
• Payne MC-7 pusher
• Piper J-3 Cub
• Rose Parakeet
• Taylorcraft BF-65
• Taylorcraft L-2

Engines on display

• Aerospace Museum of California - Franklin 0-150 (4AC-150)

Specifications (4AC-150)

Data from Jane's all the World's Aircraft 1938.^[1]

General characteristics

• Type: 4-cylinder air-cooled horizontally opposed aircraft piston engine
• Bore: 3.625 in (92.1 mm)
• Stroke: 3.625 in (92.1 mm)
• Displacement: 149.6 cu in (2.45 L)
• Length: 27.5 in (70 cm)
• Width: 34.375 in (87.3 cm)
• Height: 18.375 in (46.7 cm)
• Dry weight: 155 lb (70 kg)

Components

• Valvetrain: Pushrod and rocker operated overhead valves. One intake, one exhaust
• Fuel system: Stromberg NA-S2 updraught carburetor
• Fuel type: 70 Octane gasoline
• Oil system: Wet sump full pressure system
• Cooling system: Air-cooled

Performance

• Power output: 40 hp (30 kW) at 1,875 rpm
• Compression ratio: 6.66:1
• Fuel consumption: 4.4 gal/h (17 L/h)
• Specific fuel consumption: 0.54 lb/hp/h

See also

Comparable engines

• Lycoming O-145

Related lists

• List of aircraft engines

References

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

By displacementTwo-cylinder engines

By displacement	O-110 O-120
By company designation	2A-110 2A-120 2A4-45 2A4-49 2AL-112

Four-cylinder engines

By displacement	O-150 O-170 O-175 O-180 O-200 O-225 O-235
By company designation	4A-225 4A-235 4A4-100 4A4-75 4A4-85 4A4-95 4AC-150 4AC-171 4AC-176 4AC-199 4ACG-176 4AL-225 Sport 4

Six-cylinder engines

By displacement	O-265 O-300 O-315 O-335 O-350 O-405 O-425 O-500
By company designation	6A-335 6A-350 6A3 6A4 6A8-215 6AC-264 6AC-298 6AC-403 6ACV-245 6AG-335 6AG4-185 6AG6-245 6AGS-335 6AGS6-245 6AL-315 6AL-335 6AL-500 6ALV-335 6AS-335 6V-335 6V4 6V6-245-B16F 6V6-245 6V6-300-D16FT 6V6-300 6VS-335

Eight-cylinder engines

By displacement	O-400 O-540
By company designation	8AC-398 8ACG-398 8ACG-538 8ACGSA-538 8ACSA-538

12-cylinder engines

By displacement	O-595 O-805
By company designation	12AC-596 12AC-806