# McCulloch O-100 > Mediated Wiki article. Canonical URL: https://mediated.wiki/source/McCulloch_O-100 > Markdown URL: https://mediated.wiki/source/McCulloch_O-100.md > Source: https://en.wikipedia.org/wiki/McCulloch_O-100 > Source revision: 1336868183 > License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) 1950 4-cylinder piston engine This article needs more citations. Please help improve this article by adding citations to reliable sources in this article. Unsourced material may be challenged and removed. Find sources: "McCulloch O-100" – news · newspapers · books · scholar · JSTOR (January 2025) (Learn how and when to remove this message) McCulloch O-100 McCulloch O-100-1 on display at Texas Air Museum - Stinson Chapter Type Piston engine horizontally opposed National origin United States Manufacturer McCulloch Aircraft Corporation McCulloch Motors Corporation 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.[1] Developed from McCulloch 4 cylinder Model 4300C (O-90-1) 1945–1952 Developed into McCulloch 6 cylinder Model 6318 (O-150-2) 1955–1972 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.[2] 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.[3] ## Variants *Horizontally-Opposed Piston Engines*[4] ### 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](/source/Moorabbin_Air_Museum) - Moorabbin Airport, Melbourne Australia[5] ### United States - Wings of History Air Museum - San Martin, California - [Texas Air Museum - Stinson Chapter](/source/Texas_Air_Museum_-_Stinson_Chapter) - San Antonio, Texas - [Combat Air Museum](/source/Combat_Air_Museum) - Topeka Regional Airport at Forbes Field, Topeka, Kansas ## Specifications (McCulloch O-100-1) McCulloch O-100-1 (model 4318A) on display at the Wings of History Air Museum *Data from* *McCulloch 4318 Engine Manual*[6] ### General characteristics - **Type:** opposed (flat) 4-cylinder [piston engine](/source/Piston_engine) - **[Bore](/source/Bore_(engine)):** 3+3⁄16 in (81.0 mm) - **[Stroke](/source/Stroke_(engine)):** 3+1⁄8 in (79.4 mm) - **[Displacement](/source/Engine_displacement):** 100 in3 (1.6 L) - **Length:** 26 in (660 mm) - **Diameter:** 27 in (690 mm) - **[Dry weight](/source/Dry_weight):** 83 lb (38 kg) ### Components - **Fuel system:** downdraft [carburetor](/source/Carburetor) - **Fuel type:** 115/145 [RON](/source/Octane_rating) - **Oil system:** [Dry sump](/source/Dry_sump) - **Cooling system:** [Air-cooled](/source/Air-cooled) ### Performance - **Power output:** 72 hp (54 kW) at 4,100 [rpm](/source/Revolutions_per_minute) (takeoff) - **[Specific power](/source/Power_density):** 0.66 hp/in3 - **[Compression ratio](/source/Compression_ratio):** 8:1 - **[Power-to-weight ratio](/source/Power-to-weight_ratio):** 0.82 hp/lb ## See also - [List of aircraft engines](/source/List_of_aircraft_engines) ## References 1. **[^](#cite_ref-1)** ["Wings of History Air Museum - McCulloch O-100-1 (model 4318A)"](https://www.wingsofhistory.org/mcculloch-40-hp/). *wingsofhistory.org*. Retrieved January 23, 2025. 1. **[^](#cite_ref-2)** McCutcheon, Kimble D. (December 21, 2014). ["McCulloch Aircraft Engines"](https://www.enginehistory.org/members/McCulloch). *Aircraft Engine Historical Society*. Huntsville, AL. Retrieved January 21, 2025.] 1. **[^](#cite_ref-3)** ["Aeroengines AZ |"](https://aeroenginesaz.com/en/brand_mcculloch/%22Aerospace). *www.aeroenginesaz.com*. 1. **[^](#cite_ref-4)** ["McCULLOCH"](https://aeroenginesaz.com/en/brand_mcculloch). *www.aeroenginesaz.com*. 1. **[^](#cite_ref-5)** ["McCulloch 43180-100-1"](https://www.aarg.com.au/mcculloch.html). *Moorabbin Air Museum*. 1. **[^](#cite_ref-scribd_6-0)** ["Mcculloch 4318 Engine Manual"](https://www.scribd.com/document/464274867/). *scribd.com*. Retrieved January 23, 2025. v t e United States military piston aircraft engine designation system H (four-bank H-configuration inline) H-1640 XH-2240 XH-2470 XH-2600 XH-3130 XH-3730 H-4070 IV (inverted-V inline) IV-1430 IV-2040 IV-2220 L (single-bank inline) L-330 L-365 L-375 L-390 L-410 L-440 L-510 L-825 O (opposed) O-15 O-40 O-45 O-90 O-100 O-145 O-150 O-170 O-175 O-180 O-190 O-200 (C) O-200 (F) O-205 O-235 O-290 O-300 O-335 O-360 (C) O-360 (L) O-405 O-425 O-435 O-470 O-480 O-520 O-540 (F) O-540 (L) O-550 O-580 O-805 O-1230 R (radial) R-250 R-265 R-270 R-370 (LB) R-370 (K) R-420 R-440 R-500 R-540 (W) R-540 (K) R-545 R-550 R-600 R-670 R-680 R-720 R-755 R-760 R-790 R-830 R-915 R-975 DR-980 R-985 R-1044 R-1300 R-1340 R-1454 R-1510 R-1535 R-1640 R-1670 R-1690 R-1740 R-1750 R-1820 R-1830 R-1860 R-2000 R-2060 R-2160 R-2180 R-2600 R-2800 R-3350 R-4090 R-4360 R-7755 V (upright-V inline) V-720 V-1150 V-1237 V-1400 V-1440 V-1460 V-1510 V-1560 V-1570 V-1650 (P) V-1710 V-1950 V-3420 V (inverted-V inline) V-770 V-1650 (L) VG (inverted-V inline) VG-1410 W (three-bank W-configuration inline) W-2779 See also: X-1800 US military gas turbine aeroengines Piston engine configurations --- Adapted from the Wikipedia article [McCulloch O-100](https://en.wikipedia.org/wiki/McCulloch_O-100) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/McCulloch_O-100?action=history)). 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