McCulloch O-100
{{short description|1950 4-cylinder piston engine}}
{{Use American English|date=January 2025}}
{{More citations needed|article|date=January 2025}}
| {{Infobox aircraft begin
| name = McCulloch O-100 | image = File:McCulloch O-100-1.jpg|thumb|McCulloch O-100-1 Drone Engine | caption = McCulloch O-100-1 on display at Texas Air Museum - Stinson Chapter }} {{Infobox aircraft engine |type= Piston engine horizontally opposed |manufacturer= McCulloch Aircraft Corporation McCulloch Motors Corporation |national origin= United States |first run= 1949 |major applications= Benson B-8M autogyros; Radioplane Model PR-15 (OQ-6) and MQM 33 (Q-19); Model O-15-3 Righter Mfr. Co.{{Cite web|url=https://www.wingsofhistory.org/mcculloch-40-hp/|title=Wings of History Air Museum - McCulloch O-100-1 (model 4318A)|website=wingsofhistory.org|access-date=January 23, 2025}} |number built= |program cost= |unit cost= |developed from= McCulloch 4 cylinder Model 4300C (O-90-1) 1945–1952 |developed into= McCulloch 6 cylinder Model 6318 (O-150-2) 1955–1972 |variants with their own articles = }} |
The McCulloch O-100 is a four-cylinder, air cooled four piston drone engine developed by the McCulloch Aircraft Corporation (later to become the McCulloch Motors Corp.) which was founded 1943 in Milwaukee, Wisconsin and later moved to Los Angeles, California. The aircraft corporation was formed from the McCulloch Engineering Company.{{cite web |last=McCutcheon |first=Kimble D. |date=21 December 2014 |title= McCulloch Aircraft Engines |url=https://www.enginehistory.org/members/McCulloch |website=Aircraft Engine Historical Society |location=Huntsville, AL |access-date=January 21, 2025}}]
In 1972, the corporation was renamed McCulloch Motors Corp. of Los Angeles and sold to Northrop-Ventura.
Development
The McCulloch line of engines consisted of small 1, 2, 4 and 6 cylinder 2-stroke engines. The first engines were used for industrial motor pumps and chainsaws. In the 1940s, military contract started with a 4-cylinder model 4300 (Military O-88) engine to be used in aeronautical target drones. Later with bigger Horsepower (H.P.) development, the engines had experimental aircraft applications.{{Cite web|url=https://aeroenginesaz.com/en/brand_mcculloch/%22Aerospace|title=Aeroengines AZ {{pipe}}|website=www.aeroenginesaz.com}}
Variants
Horizontally-Opposed Piston Engines{{Cite web|url=https://aeroenginesaz.com/en/brand_mcculloch|title=McCULLOCH|website=www.aeroenginesaz.com}}
=4-Cylinder=
- Model 4300 (Mil O-88)
- Model 4300C
- Model 4318A (Mil O-100-1)
- Model 4318B (mil O-100-2)
=6-Cylinder=
- Model 6318 (O-150-2)
- Model TC-6150 (O-150-4)
Display
=Australia=
- Moorabbin Air Museum - Moorabbin Airport, Melbourne Australia{{Cite web|url=https://www.aarg.com.au/mcculloch.html|title=McCulloch 43180-100-1|website=Moorabbin Air Museum}}
=United States=
- Wings of History Air Museum - San Martin, California
- Texas Air Museum - Stinson Chapter - San Antonio, Texas
- Combat Air Museum - Topeka Regional Airport at Forbes Field, Topeka, Kansas
Specifications (McCulloch O-100-1)
File:McCulloch O-100-1 (model 4318A) on display at the Wings of History Air Museum.jpg
{{pistonspecs
|type=opposed (flat) 4-cylinder piston engine
|ref=McCulloch 4318 Engine Manual{{cite web|url=https://www.scribd.com/document/464274867/|website=scribd.com|title=Mcculloch 4318 Engine Manual|access-date=January 23, 2025}}
|bore={{cvt|3+3/16|in|mm|1}}
|stroke={{cvt|3+1/8|in|mm|1}}
|displacement={{convert|100|in3|L|abbr=on}}
|length={{convert|26|in|mm|abbr=on}}
|diameter={{convert|27|in|mm|abbr=on}}
|width=
|height=
|weight={{convert|83|lb|kg|abbr=on}}
|valvetrain=
|supercharger=
|turbocharger=
|fuelsystem= downdraft carburetor
|fueltype=115/145 RON
|oilsystem=Dry sump
|coolingsystem=Air-cooled
|power={{convert|72|hp|kW|abbr=on}} at 4,100 rpm (takeoff)
|specpower=0.66 hp/in{{sup|3}}
|compression=8:1
|fuelcon=
|specfuelcon=
|oilcon=
|power/weight=0.82 hp/lb
}}