World Library  
Flag as Inappropriate
Email this Article

Lycoming O-145

Article Id: WHEBN0020794210
Reproduction Date:

Title: Lycoming O-145  
Author: World Heritage Encyclopedia
Language: English
Subject: Piper J-3 Cub, Britten-Norman BN-1, Stinson Voyager, Lycoming H-2470, Lycoming O-1230
Collection: Aircraft Piston Engines 1930–1939, Lycoming Aircraft Engines
Publisher: World Heritage Encyclopedia

Lycoming O-145

Preserved Lycoming O-145
Type Piston aero-engine
National origin USA
Manufacturer Lycoming Engines

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 1
  • Variants 2
  • Applications 3
  • Specifications (GO-145-C2) 4
  • See also 5
  • References 6

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]


Four-cylinder, direct drive, 55 hp (41 kW), single ignition[2]
Four-cylinder, direct drive, 55 hp (41 kW), single ignition, with starter and generator installed[3]
Four-cylinder, direct drive, 65 hp (48 kW), single ignition[1]
Four-cylinder, direct drive, 65 hp (48 kW), dual ignition[1]
Four-cylinder, direct drive, 65 hp (48 kW), dual ignition[1]
Four-cylinder, direct drive, 75 hp (56 kW), single ignition[1]
Four-cylinder, direct drive, 75 hp (56 kW), dual ignition[1]
Four-cylinder, reduction gearbox, 75 hp (56 kW), single ignition[1]
Four-cylinder, reduction gearbox, 75 hp (56 kW), dual ignition[1]
Four-cylinder, reduction gearbox, 75 hp (56 kW), dual ignition[1]



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)


  • 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


See also

Related lists


  1. ^ a b c d e f g h i j k l m n o  
  2. ^ a b c d e Christy, Joe: Engines for Homebuilt Aircraft & Ultralights, pages 64-65 TAB Books, 1983. ISBN 0-8306-2347-7
  3. ^ a b c d e f g h i Boggs, Jerry (n.d.). "Super KR-1". Retrieved 2008-12-21. 
  4. ^ Rotor & Wing (January 2005). "Lycoming Engines". Retrieved 2008-12-21. 
This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.

Copyright © World Library Foundation. All rights reserved. eBooks from Project Gutenberg are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.