Lycoming O-145

O-145
	Preserved Lycoming O-145
Type	Piston aero-engine
National origin	United States
Manufacturer	Lycoming Engines
First run	1933
Major applications	Piper J-3 Cub ; Piper J-5 ; Piper PA-15 Vagabond ; Aeronca Chief family
Produced	1938-1949
Developed into	Lycoming O-233 ; Lycoming O-235

The Lycoming O-145 is a family of small, low-horsepower, four-cylinder, air-cooled engines. It was Lycoming Engines' first horizontally opposed aircraft engine and was produced from 1938 until the late 1940s. The family includes the reduction-geared GO-145.^[1]^[2]^[3] The O-145 received its Approved Type Certificate on 13 Jun 1938.

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]
O-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) at 2550 rpm, single ignition, 155 lb^[1]
O-145-B2: Four-cylinder, direct drive, 65 hp (48 kW) at 2550 rpm, dual ignition, 166 lb^[1]
O-145-B3: Four-cylinder, direct drive, 65 hp (48 kW) at 2550 rpm, dual ignition, 169 lb^[1]
O-145-C1: Four-cylinder, direct drive, 75 hp (56 kW) at 3100 rpm, single ignition, 155 lb^[1]
O-145-C2: Four-cylinder, direct drive, 75 hp (56 kW) at 3100 rpm, dual ignition, 166 lb^[1]
GO-145-C1: Four-cylinder, reduction gearbox, 75 hp (56 kW) at 3200 rpm, single ignition, 182 lb^[1]
GO-145-C2: Four-cylinder, reduction gearbox, 75 hp (56 kW) at 3200 rpm, dual ignition, 193 lb^[1]
GO-145-C3: Four-cylinder, reduction gearbox, 75 hp (56 kW) at 3200 rpm, dual ignition, 195 lb^[1]

Applications

O-145

Aeronca Chief 50L, 50LA, 65LA
Aeronca Super Chief 65LB
Aeronca Tandem 50TL, 60TL, 65TL
Airdrome Fokker D-VIII
Luscombe 8B
Mooney Mite M-18L
Piper J-3L Cub, most often the 65 hp version
Piper J-4F Cub Coupe
Piper PA-8 Skycycle
Carlson Skycycle
Piper PA-15 Vagabond
Porterfield Collegiate LP-50, LP-55, LP-65
Taylorcraft BL series (BL-50, BL-65, BL-12-65, etc.)
Taylorcraft DL
Taylorcraft Plus C

GO-145

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)

References

^ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k ^l ^m ⁿ ^o Federal Aviation Administration (August 1949). "Approved Type Certificate 210". Retrieved 2008-12-21.
^ ^a ^b ^c ^d ^e Christy, Joe: Engines for Homebuilt Aircraft & Ultralights, pages 64-65 TAB Books, 1983. ISBN 0-8306-2347-7
^ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ Boggs, Jerry (n.d.). "Super KR-1". Retrieved 2008-12-21.{{cite web}}: CS1 maint: year (link)
^ Rotor & Wing (January 2005). "Lycoming Engines". Archived from the original on 2009-04-14. Retrieved 2008-12-21.