Lycoming GSO-580

{{about|the 1959-era geared, eight-cylinder aircraft engine series|the 1997 six-cylinder engine|Lycoming IO-580}}  {{infobox aero engine |name=GSO-580 |image= |caption= |engine_type=[[Piston]] [[aircraft engine|aero-engine]] |manufacturer=[[Lycoming Engines]] |first_run= |produced=1948–1961 |major_applications={{ubl | [[Beechcraft Model 34]] | [[Fairchild XNQ]] }} }}

The '''Lycoming GSO-580''' is a family of eight-cylinder [[Flat engine|horizontally opposed]], [[supercharger|supercharged]], [[carburetor]]-equipped aircraft engines for both airplanes and [[helicopters]], manufactured by [[Lycoming Engines]] in the late 1950s and early 1960s.<ref name="E256">{{cite web|url = http://www.airweb.faa.gov/Regulatory_and_Guidance_Library/rgMakeModel.nsf/0/72B3B8E50E7712F586256B1B00667681?OpenDocument&Highlight=580|title = AIRCRAFT ENGINE SPECIFICATION, Revision 6|access-date = 2009-01-04|last = [[Federal Aviation Administration]]|date=April 1959}}</ref><ref name="E285">{{cite web|url = http://www.airweb.faa.gov/Regulatory_and_Guidance_Library/rgMakeModel.nsf/0/985CC61D95E1681A8525670E004F6395?OpenDocument&Highlight=580|title = AIRCRAFT ENGINE SPECIFICATION, Revision 2|access-date = 2009-01-04|last = [[Federal Aviation Administration]]|date=March 1959}}</ref>

The family includes the original GSO-580 [[fixed-wing aircraft]] engine series, as well as the later '''SO-580''' and '''VSO-580''' helicopter engines. There is no non-supercharged, non-geared version of the engine, which would have been designated O-580 and therefore the base model is the GSO-580.<ref name="E256" /><ref name="E285" />

==Design and development== The GSO-580 family of engines covers a range from {{convert|375|hp|kW|0|abbr=on}} to {{convert|400|hp|kW|0|abbr=on}}. All have a [[Engine displacement|displacement]] of {{convert|578|cuin|L|2|abbr=none}} and the cylinders have air-cooled [[Cylinder head|heads]]. Compared to other horizontally opposed engines of similar displacement this family of engines produces high output power by supercharging and high maximum rpm, at the cost of higher weight.<ref name="E256" /><ref name="E285" />

The GSO-580 series was [[type certificate|certified]] under Type Certificate 256, while the SO-580 and VSO-580 series were certified under type certificate 285. Both were manufactured under Production Certificate No. 3.<ref name="E256" /><ref name="E285" />

==Variants== ;O-580-1:Military variant similar to the GSO-580-D{{Citation needed|date=January 2019}} ;GSO-580 :Eight-cylinder, horizontally opposed, geared-drive, supercharged, {{convert|578|cuin|L|2|abbr=none}}, {{convert|375|hp|kW|0|abbr=on}} at 3300 rpm for take-off, {{convert|320|hp|kW|0|abbr=on}} at 3000 rpm continuous, dry weight {{convert|619|lb|kg|0|abbr=on}}, Bendix PSH-9BDE carburetor. Minimum fuel grade 91/98 [[avgas]]. Designation indicates ''Geared, Supercharged, Opposed''.<ref name="E256" /> ;GSO-580-B :Eight-cylinder, horizontally opposed, geared-drive, supercharged, {{convert|578|cuin|L|2|abbr=none}}, {{convert|400|hp|kW|0|abbr=on}} at 3300 rpm for take-off, {{convert|350|hp|kW|0|abbr=on}} at 3000 rpm continuous, dry weight {{convert|624|lb|kg|0|abbr=on}}, Bendix PSH-9BDE carburetor. Minimum fuel grade 100/130 avgas. Designation indicates ''Geared, Supercharged, Opposed''.<ref name="E256" /> ;GSO-580-C :Eight-cylinder, horizontally opposed, geared-drive, supercharged, {{convert|578|cuin|L|2|abbr=none}}, {{convert|375|hp|kW|0|abbr=on}} at 3300 rpm for take-off, {{convert|320|hp|kW|0|abbr=on}} at 3000 rpm continuous, dry weight {{convert|604|lb|kg|0|abbr=on}}, Bendix PS-9BDE carburetor. Minimum fuel grade 91/98 avgas. Designation indicates ''Geared, Supercharged, Opposed''.<ref name="E256" /> ;GSO-580-D :Eight-cylinder, horizontally opposed, geared-drive, supercharged, {{convert|578|cuin|L|2|abbr=none}}, {{convert|400|hp|kW|0|abbr=on}} at 3300 rpm for take-off, {{convert|350|hp|kW|0|abbr=on}} at 3000 rpm continuous, dry weight {{convert|608|lb|kg|0|abbr=on}}, Bendix PS-9BDE carburetor. Minimum fuel grade 100/130 avgas. Designation indicates ''Geared, Supercharged, Opposed''.<ref name="E256" /> ;SO-580-A1A :Eight-cylinder, horizontally opposed, geared-drive, supercharged, {{convert|578|cuin|L|2|abbr=none}}, {{convert|400|hp|kW|0|abbr=on}} at 3300 rpm for take-off, {{convert|350|hp|kW|0|abbr=on}} at 3000 rpm continuous, dry weight {{convert|596|lb|kg|0|abbr=on}}, Bendix PS-9BDE carburetor. Minimum fuel grade 100/130 avgas. Designation indicates ''Supercharged, Opposed''. Designed for horizontal or up to 35 degrees nose-up helicopter installation.<ref name="E285" /> ;SO-580-A1B :Eight-cylinder, horizontally opposed, geared-drive, supercharged, {{convert|578|cuin|L|2|abbr=none}}, {{convert|400|hp|kW|0|abbr=on}} at 3300 rpm for take-off, {{convert|350|hp|kW|0|abbr=on}} at 3000 rpm continuous, dry weight {{convert|578|lb|kg|0|abbr=on}}, Bendix PS-9BDE carburetor. Minimum fuel grade 100/130 avgas. Designation indicates ''Supercharged, Opposed''. Designed for horizontal or up to 35 degrees nose-up helicopter installation.<ref name="E285" /> ;VSO-580-A1A :Eight-cylinder, horizontally opposed, geared-drive, supercharged, {{convert|578|cuin|L|2|abbr=none}}, {{convert|400|hp|kW|0|abbr=on}} at 3300 rpm for take-off, {{convert|350|hp|kW|0|abbr=on}} at 3000 rpm continuous, dry weight {{convert|592|lb|kg|0|abbr=on}}, Bendix PS-9BDE carburetor. Minimum fuel grade 100/130 avgas. Designation indicates ''Vertical-mounted, Supercharged, Opposed''. Designed for vertical helicopter installation.<ref name="E285" />

==Applications== ;GSO-580 *[[Beechcraft Model 34]] *[[Cessna 308]]<ref name="Cessnas">{{cite web|url = http://www.wingsoverkansas.com/features/article.asp?id=461|title = The Cessnas that got away|access-date = 2008-12-22|last = Murphy|first = Daryl|year = 2006|archive-url = https://web.archive.org/web/20090227001732/http://www.wingsoverkansas.com/features/article.asp?id=461|archive-date = 2009-02-27|url-status = dead}}</ref> *[[Fairchild XNQ]] ;SO-580 *[[Doman LZ-5]]<ref name="NEAM">{{cite web|url = http://www.neam.org/articles/a_doman1.asp|title = Doman Helicopters: Unsung Innovations, Part 1|access-date = 2009-01-04|last = Collinge|first = Ken & Glidden S. Doman|year = 2006}}</ref>

==Specifications (VSO-580-A1A)== {{pistonspecs|   |ref=FAA AIRCRAFT ENGINE SPECIFICATION E-285, Revision 2<ref name="E285" /> |type=8-cylinder fuel-injected horizontally opposed, vertically mounted, helicopter engine |bore={{convert|4.875|in|mm|abbr=on}} |stroke={{convert|3.875|in|mm|abbr=on}} |displacement={{convert|578|cuin|L|2|abbr=on}} |length= |diameter= |width= |height= |weight={{convert|592|lb|kg|0|abbr=on}} dry |valvetrain= |supercharger=7.91:1 drive ratio |turbocharger= |fuelsystem=Bendix PS9BDE carburetor |fueltype=100/130 [[avgas]] minimum |oilsystem= |coolingsystem=air-cooled |power={{convert|400|hp|kW|abbr=on}} at 3300 rpm |specpower=0.51 hp/in³ (33.3 kW/L) |compression=7.30:1 |fuelcon= |specfuelcon= |oilcon= |power/weight={{convert|0.68|hp/lb|kW/kg|abbr=on}}

|designer= |reduction_gear=

|general_other= |components_other= |performance_other= }}

==See also== {{aircontent  |see also= *[[Lycoming IO-580]]  |related=

|similar aircraft=

|lists= *[[List of aircraft engines]]  |similar engines=

}}

==References== {{reflist}}

[[Category:Lycoming aircraft engines|GSO-580]] [[Category:1950s aircraft piston engines]] [[Category:Boxer engines]] [[Category:Eight-cylinder engines]] [[Category:Air-cooled aircraft piston engines]]