# Franklin O-805 > Mediated Wiki article. Canonical URL: https://mediated.wiki/source/Franklin_O-805 > Markdown URL: https://mediated.wiki/source/Franklin_O-805.md > Source: https://en.wikipedia.org/wiki/Franklin_O-805 > Source revision: 1353288803 > License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) American air-cooled aircraft piston engine designed in the mid-1940s O-805/12AC Franklin O-805 on display at the National Museum of the United States Air Force Type 12-cylinder horizontally opposed piston engine Manufacturer Franklin Engine Company First run c. 1945 The **Franklin O-805** (company designation **12AC**) was an American air-cooled aircraft piston engine, designed in the mid-1940s and was to be used in radio-controlled pilotless drones that were to be guided from an accompanying control plane. Due to project requirement changes and cancellations the engine was not produced.[1] A smaller displacement 12-cylinder Franklin engine of 1941 was known as the **O-595** or **12AC-596**. ## Variants ### O-805 **12AC-806** - 450 hp (336 kW)0 **12ACG-806 (XO-805-1)** - 456 hp (340 kW) at 3,200 rpm, geared to 0.632:1. **12ACGSA-806 (XO-805-3 and O-805-5)** - 500 hp (373 kW) at 3,200 rpm, supercharged and geared to 0.632:1 (XO-805-3), or to 0.587:1 (O-805-5). ### O-595 **12AC-596** - 300 hp (224 kW) at 2,600 rpm **12ACG-596** - 350 hp (261 kW) at 3,500 rpm ## Applications (intended) - [Interstate XBQ-5](/source/Interstate_XBQ-5) - [Interstate XTD2R-1](/source/Interstate_XTD2R-1) ## Survivors - There is an O-805-2 on display at the [New England Air Museum](/source/New_England_Air_Museum), [Bradley International Airport](/source/Bradley_International_Airport), Windsor Locks, CT [2] - One surfaced and was sold privately in August, 2016, on eBay for US$8500.[3] ## Specifications (12ACGSA-806/XO-805-3) ### General characteristics - **Type:** 12-cylinder air-cooled [horizontally opposed](/source/Flat_engine) aircraft piston engine - **[Bore](/source/Bore_(engine)):** 4.625 in (117.5 mm) - **[Stroke](/source/Stroke_(engine)):** 4.0 in (101.6 mm) - **[Displacement](/source/Engine_displacement):** 806.4 cu in (13.2 L) ### Components - **[Valvetrain](/source/Valvetrain):** OHV - **Cooling system:** Air-cooled - **[Reduction gear](/source/Propeller_speed_reduction_unit):** 0.632 ### Performance - **Power output:** 500 hp (373 kW) at 3,200 rpm ## See also **Related lists** - [List of aircraft engines](/source/List_of_aircraft_engines) ## References **Notes** 1. **[^](#cite_ref-1)** NMUSAF (June 8, 2015), [*Franklin O-805-2*](https://www.nationalmuseum.af.mil/Visit/MuseumExhibits/FactSheets/Display/tabid/509/Article/195703/franklin-o-805-2.aspx), [National Museum of the United States Air Force](/source/National_Museum_of_the_United_States_Air_Force) 1. **[^](#cite_ref-2)** ["New England Air Museum"](http://neam.org/index.php?option=com_content&view=article&id=1073). 1. **[^](#cite_ref-3)** ["13 Liter WW2 Drone Engine: Super Rare Franklin 0-805"](http://bringatrailer.com/2016/08/29/13-liter-ww2-drone-engine-super-rare-franklin-0-805/). 29 August 2016. ## External links Wikimedia Commons has media related to [Franklin O-805](https://commons.wikimedia.org/wiki/Category:Franklin_O-805). - [A table showing the relationship of the military models](http://home.comcast.net/~aeroengine/FrkFam.html) v t e Franklin aircraft engines By displacement O-110 O-120 O-150 O-170 O-175 O-180 O-200 O-225 O-235 O-265 O-300 O-315 O-335 O-350 O-400 O-405 O-425 O-500 O-540 O-595 O-805 Two-cylinder engines By displacement O-110 O-120 By company designation 2A-110 2A-120 2A4-45 2A4-49 2AL-112 Four-cylinder engines By displacement O-150 O-170 O-175 O-180 O-200 O-225 O-235 By company designation 4A-225 4A-235 4A4-100 4A4-75 4A4-85 4A4-95 4AC-150 4AC-171 4AC-176 4AC-199 4ACG-176 4AL-225 Sport 4 Six-cylinder engines By displacement O-265 O-300 O-315 O-335 O-350 O-405 O-425 O-500 By company designation 6A-335 6A-350 6A3 6A4 6A8-215 6AC-264 6AC-298 6AC-403 6ACV-245 6AG-335 6AG4-185 6AG6-245 6AGS-335 6AGS6-245 6AL-315 6AL-335 6AL-500 6ALV-335 6AS-335 6V-335 6V4 6V6-245-B16F 6V6-245 6V6-300-D16FT 6V6-300 6VS-335 Eight-cylinder engines By displacement O-400 O-540 By company designation 8AC-398 8ACG-398 8ACG-538 8ACGSA-538 8ACSA-538 12-cylinder engines By displacement O-595 O-805 By company designation 12AC-596 12AC-806 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 This aircraft engine article is missing some (or all) of its specifications. If you have a source, you can help Wikipedia by adding them. --- Adapted from the Wikipedia article [Franklin O-805](https://en.wikipedia.org/wiki/Franklin_O-805) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Franklin_O-805?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.