# Franklin O-300 > Mediated Wiki article. Canonical URL: https://mediated.wiki/source/Franklin_O-300 > Markdown URL: https://mediated.wiki/source/Franklin_O-300.md > Source: https://en.wikipedia.org/wiki/Franklin_O-300 > Source revision: 1352978428 > License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) Early 1940s American air-cooled aircraft engine O-300/6AC-298 Type Piston aircraft engine National origin United States Manufacturer Franklin Engine Company First run 1941 The **Franklin O-300** (company designation **6AC-298**) was an American air-cooled aircraft engine of the early 1940s. The engine was of [six-cylinder, horizontally-opposed layout](/source/Flat-six_engine) and [displaced](/source/Engine_displacement) 300 cu in (5 L). The power output ranged between 130 hp (97 kW) and 175 hp (130 kW) depending on variant. The **6ACG-298** featured a [geared propeller drive](/source/Propeller_speed_reduction_unit). An enlarged displacement version was known as the **O-315, 6A3** or **6AL-315.** ## Variants ### O-300 **6AC-298** **6AC-298-F3 (O-300-1)** - 130 hp (97 kW) at 2,600 rpm **6ACT-298** - 150 hp (112 kW) at 3,000 rpm **6ACT-298-J4 (O-300-3)** - 150 hp (112 kW) at 2,930 rpm **6ACT-298-35 (O-300-11)** - 150 hp (112 kW) at 2,930 rpm **6ACG-298-P5 (O-300-9)** - Geared propeller drive 0.63:1, 160 hp (119 kW) at 3,200 rpm **6ACTS-298** - Supercharged, 160 hp (119 kW) at 3,200 rpm **6ACTS-298-K4 (O-300-7)** - Supercharged, 175 hp (130 kW) at 3,000 rpm **6ACV-298** - Vertical installation for helicopters,160 hp (119 kW) at 3,250 rpm ### O-315 (6A3) **6AL-315** - 175 hp (130 kW) **6ALG-315** - 175 hp (130 kW) ## Applications ### Direct drive - [Aeronautical Products A-1](https://en.wikipedia.org/w/index.php?title=Aeronautical_Products_A-1&action=edit&redlink=1) - [Aeronautical Products A-3](https://en.wikipedia.org/w/index.php?title=Aeronautical_Products_A-3&action=edit&redlink=1) - [CNNA HL-6](/source/CNNA_HL-6) - [Culver XPQ-9](/source/Culver_Cadet) - [Culver XPQ-14, YPQ-14A, XPQ-15](/source/Culver_PQ-14_Cadet) - [Bell 30](/source/Bell_30) - [Bellanca T-14](/source/Bellanca_14-7) - [Erco XPQ-13](/source/ERCO_Ercoupe#Variants) - [Fleetwings 33](/source/Fleetwings_33) - [Hockaday Comet](/source/Hockaday_Comet) - [Piper PT-1](/source/Piper_PT-1) - [Troy A](https://en.wikipedia.org/w/index.php?title=Troy_A&action=edit&redlink=1) - [Zodiac Libra-Det](https://en.wikipedia.org/w/index.php?title=Zodiac_Libra-Det&action=edit&redlink=1) ### Geared drive - [Culver PQ-14 Cadet](/source/Culver_PQ-14_Cadet) - [Republic RC-1 Thunderbolt](/source/Republic_RC-3_Seabee) (O-315) ### Supercharged - [Northwestern XPG-1](/source/Northwestern_XPG-1) ([Waco CG-4](/source/Waco_CG-4) twin-engine conversion) ## Specifications (6AC-298) *Data from* [*[citation needed](https://en.wikipedia.org/wiki/Wikipedia:Citation_needed)*] ### General characteristics - **Type:** 6-cylinder air-cooled [horizontally opposed](/source/Flat-6) aircraft piston engine - **[Bore](/source/Bore_(engine)):** 4.25 in (108 mm) - **[Stroke](/source/Stroke_(engine)):** 3.5 in (88.9 mm) - **[Displacement](/source/Engine_displacement):** 297.9 in³ (4.88 L) - **[Dry weight](/source/Dry_weight):** 260 lb (118 kg) ### Components - **Cooling system:** Air-cooled ### Performance - **Power output:** 130 hp (97 kW) at 2,600 rpm ## See also **Comparable engines** - [Continental O-300](/source/Continental_O-300) **Related lists** - [List of aircraft engines](/source/List_of_aircraft_engines) ## References **Notes** **Bibliography** - Gunston, Bill. (1986) *World Encyclopedia of Aero Engines*. Patrick Stephens: Wellingborough. p. 57 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 --- Adapted from the Wikipedia article [Franklin O-300](https://en.wikipedia.org/wiki/Franklin_O-300) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Franklin_O-300?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.