Lycoming O-145
| O-145 | |
|---|---|
    | |
| Preserved Lycoming O-145 | |
| Type | Piston aero-engine | 
| National origin | United States | 
| Manufacturer | Lycoming Engines | 
| 
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The Lycoming O-145 is a family of small, low-horsepower, four-cylinder, air-cooled horizontally opposed aircraft engine produced from 1938 until the late 1940s by Lycoming Engines. The family includes the reduction-geared GO-145.[1][2][3]
Design and development
The O-145 was produced in three major versions, the O-145-A rated at 55 hp (41 kW), the -B rated at 65 hp (48 kW), and -C rated at 75 hp (56 kW). The "B" model was the major production model, with the "A" and "C" produced in much smaller quantities.[1][2]
All models of the series had the same bore, stroke, and displacement, additional horsepower being generated by increasing compression ratio and maximum rpm. All use a Stromberg NA-S2 or NA-S2A or Marvel MA-2 or MA-2-A carburetor. The dual ignition versions use two Scintilla SF-4L, SN4LN-20 or -21, Superior SMA-4 or Edison-Splitdorf RMA-4 magnetos.[1][2]
The original O-145-A produced 55 hp (41 kW) at 2300 rpm, weighed 165.5 lb (75 kg), and featured single ignition. In an attempt to compete with the Continental A-65, Lycoming boosted the rpm and power output to 65 hp (48 kW) at 2550 rpm, and finally 75 hp (56 kW) at 3100 rpm. The O-145 had a hard time competing with the same horsepower Continentals due to its smaller displacement, which resulted in a steeper torque curve.[1][3]
The GO-145 is a geared model, introduced in 1938, that uses a 27:17 reduction ratio (1.59:1) gearbox to produce 75 hp (56 kW) at 3200 crankshaft rpm, giving 2013 propeller rpm. The engine employs a gearbox bolted to the front of the engine and the resulting engine weighs 193 lb (88 kg) without starter or generator. The GO-145 suffered from a poor reputation for reliability, because pilots mis-handled the engine, running it at too low a cruising rpm and causing gearbox wear as a result.[1][2][3][4]
The series' type certificate expired on 2 November 1950 and no O-145-B1 or -C1 or GO-145-C1s engines produced after 1 August 1941 and O-145-B2, -B3 or -C2, or GO-145-C2 or -C3s produced after 24 August 1949 are eligible for certification. The single ignition O-145-A series, O-145-B1, and -C1 are not covered by the original type certificate.[1]
Lycoming ended production of the O-145 and replaced it with the O-235 series.[3]
Variants
- O-145-A
 - Four-cylinder, direct drive, 55 hp (41 kW), single ignition[2]
 - 0-145-A3
 - Four-cylinder, direct drive, 55 hp (41 kW), single ignition, with starter and generator installed[3]
 - O-145-B1
 - Four-cylinder, direct drive, 65 hp (48 kW), single ignition[1]
 - O-145-B2
 - Four-cylinder, direct drive, 65 hp (48 kW), dual ignition[1]
 - O-145-B3
 - Four-cylinder, direct drive, 65 hp (48 kW), dual ignition[1]
 - O-145-C1
 - Four-cylinder, direct drive, 75 hp (56 kW), single ignition[1]
 - O-145-C2
 - Four-cylinder, direct drive, 75 hp (56 kW), dual ignition[1]
 - GO-145-C1
 - Four-cylinder, reduction gearbox, 75 hp (56 kW), single ignition[1]
 - GO-145-C2
 - Four-cylinder, reduction gearbox, 75 hp (56 kW), dual ignition[1]
 - GO-145-C3
 - Four-cylinder, reduction gearbox, 75 hp (56 kW), dual ignition[1]
 
Applications
- O-145
 
- Airdrome Fokker D-VIII
 - Piper J-3L Cub, most often the 65 hp version
 - Carlson Skycycle
 - Piper PA-8 Skycycle
 
- GO-145
 
- Piper J-5 Cruiser[3]
 - Funk B75L[3]
 - General Skyfarer[3]
 - Rich Twin 1-X-2[3]
 - Shirlen Big Cootie
 
Specifications (GO-145-C2)
Data from Type Certificate 210[1]
General characteristics
- Type: Four-cylinder, reduction-geared engine
 - Bore: 3.625 in (92 mm)
 - Stroke: 3.500 in (89 mm)
 - Displacement: 144.5 in³ (2.4 L)
 - Dry weight: 193 lb (87.5 kg)
 
Components
- Fuel system: Stromberg NA-S2 or NA-S2A or Marvel MA-2 or MA-2-A carburetor
 - Fuel type: minimum 73 octane
 - Cooling system: air-cooled
 
Performance
- Power output: 75 hp at 3200 rpm (56 kW)
 - Specific power: 0.52 hp/in³ (23.3 kW/L)
 - Compression ratio: 6.5:1
 - Power-to-weight ratio: 0.39 hp/lb (0.64 kW/kg)
 
See also
- Comparable engines
 
- Related lists
 
References
| Wikimedia Commons has media related to Lycoming O-145. | 
- 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Federal Aviation Administration (August 1949). "Approved Type Certificate 210". Retrieved 2008-12-21.
 - 1 2 3 4 5 Christy, Joe: Engines for Homebuilt Aircraft & Ultralights, pages 64-65 TAB Books, 1983. ISBN 0-8306-2347-7
 - 1 2 3 4 5 6 7 8 9 Boggs, Jerry (n.d.). "Super KR-1". Retrieved 2008-12-21.
 - ↑ Rotor & Wing (January 2005). "Lycoming Engines". Retrieved 2008-12-21.
 
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