{{Short description|I-2 piston aircraft engine}} <!-- This article is a part of Wikipedia:WikiProject Aircraft. Please see Wikipedia:WikiProject Aircraft/page content for recommended layout. --> {{infobox aero engine | name=2si 540 & 500 | image= | caption= |engine_type= Two-stroke aircraft engine |manufacturer=2si |national_origin=United States |first_run= |major applications= |produced= |number_built= |developed_from= |variants_with_their_own_articles= }}
The '''2si 540''' and '''2si 500''' are a family of in-line twin-cylinder, liquid-cooled, two-stroke, dual ignition, aircraft engines that were designed for ultralight aircraft.<ref name="Cliche">Cliche, Andre: ''Ultralight Aircraft Shopper's Guide'' 8th Edition, page G-2 Cybair Limited Publishing, 2001. {{ISBN|0-9680628-1-4}}</ref>
The basic engine was originally designed and produced by JLO-Motorenwerke of Germany and was later acquired by the AMW Cuyuna Engine Company of Beaufort, South Carolina and marketed under the ''Cuyuna'' brand name. Later the engine was marketed by Cuyuna under the Two Stroke International (2si) brand. Cuyuna no longer markets engines for aircraft use although the 540 is still in production as a sport vehicle engine.<ref name="Cliche" /><ref name="About2si">{{cite web |date=n.d. |title=2si Company Profile |url=http://www.2si.com/2si_company_profile.htm |url-status=dead |archiveurl=https://web.archive.org/web/20100115032358/http://www.2si.com/2si_company_profile.htm |archivedate=2010-01-15 |accessdate=2010-02-16}}</ref><ref name="540L90">{{cite web |date=n.d. |title=Engine Models 500L–85 & 540L-90 Racing/Sport Vehicle Engines |url=http://www.2si.com/500l_540l_sport_spec.htm |url-status=dead |archiveurl=https://web.archive.org/web/20100105001317/http://www.2si.com/500l_540l_sport_spec.htm |archivedate=2010-01-05 |accessdate=2010-02-18}}</ref>
==Development== The 540 is a conventional twin-cylinder engine that weighs {{convert|90|lb|kg|0|abbr=on}} in its L70 aircraft version. The engine features dual capacitor discharge ignition (single in the sport vehicle version), reed valve porting, tuned exhaust system, two slide venturi-type carburetors, liquid cooling, fuel pump, a cast iron cylinder liner, ball, needle and roller bearings throughout. The aircraft version was offered with an optional gearbox reduction system. Starting is electric starter or recoil starter.<ref name="Cliche" /><ref name="540L90" /><ref name="Aerocrafter">Purdy, Don: ''AeroCrafter - Homebuilt Aircraft Sourcebook'', page 69. BAI Communications. {{ISBN|0-9636409-4-1}}</ref>
The 500L85 is a special engine that was developed from the 540, by reducing the cylinder bore from {{convert|75|mm|in|3|abbr=on}} to {{convert|72|mm|in|3|abbr=on}}. This was done to reduce the displacement to under 500 cc and allow the engine to be used for Formula 500 auto racing.<ref name="540L90" />
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==Variants== ;500L-85 :Gasoline sport vehicle engine for Formula 500 auto racing. Dual carburetors, {{convert|83|hp|kW|0|abbr=on}} at 8000 rpm, still in production.<ref name="540L90" /> ;540-L70 :Gasoline aircraft engine, dual carburetors, {{convert|70|hp|kW|0|abbr=on}} at 7000 rpm, weight {{convert|90|lb|kg|0|abbr=on}}, out of production.<ref name="Cliche" /><ref name="Aerocrafter" /> ;540L-90 :Gasoline sport vehicle engine for auto racing, kart and all-terrain vehicle applications. Dual carburetors, {{convert|89|hp|kW|0|abbr=on}} at 8000 rpm, still in production.<ref name="540L90" />
==Applications== ;Aircraft *RagWing RW8 PT2S ;Automotive *Formula 500
==Specifications (540-L70 aircraft engine) == {{pistonspecs| <!-- If you do not understand how to use this template, please ask at Wikipedia talk:WikiProject Aircraft --> <!-- Please include units where appropriate (main comes first, alt in parentheses). If data are missing, leave the parameter blank (do not delete it). For additional lines, end your alt units with )</li> and start a new, fully-formatted line with <li> --> |ref=Cliche<ref name="Cliche" /> & 2si<ref name="540L90" /> |type=Twin-cylinder, two-stroke aircraft engine |bore={{convert|75|mm|in|2|abbr=on}} |stroke={{convert|61|mm|in|2|abbr=on}} |displacement=540 cc (32.95 cu in) |length={{convert|17.5|in|mm|2|abbr=on}} |diameter= |width={{convert|14.0|in|mm|2|abbr=on}} |height={{convert|15.0|in|mm|2|abbr=on}} |weight={{convert|90|lb|kg|0|abbr=on}} |valvetrain=reed valve porting |supercharger= |turbocharger= |fuelsystem= |fueltype=Minimum 92 octane |oilsystem=premixed oil and fuel |coolingsystem=liquid cooled |power={{convert|70|hp|kW|0|abbr=on}} at 7000 rpm |specpower= |compression= |fuelcon= |specfuelcon= |oilcon= |power/weight=
|designer= |reduction_gear=optional gearbox
|general_other= |components_other= |performance_other= }}
==See also== {{aircontent <!-- include as many lines are appropriate. additional lines/entries with carriage return. --> |see also= *List of aircraft engines *Hirth 3503 *Rotax 582 |related=<!-- related developments --> |similar aircraft=<!-- similar or comparable aircraft --> |lists= }}
==References== {{Reflist}} <!-- ==External links== -->
{{2si}}
Category:Two-stroke aircraft piston engines Category:Liquid-cooled aircraft piston engines Category:Straight-twin engines Category:2si engines