2si 540
{{Short description|I-2 piston aircraft engine}}
| {{Infobox Aircraft Begin
| name=2si 540 & 500 | image= | caption= }}{{Infobox Aircraft Engine |type= Two-stroke aircraft engine |manufacturer=2si |national origin=United States |first run= |major applications= |produced= |number built= |program cost= |unit cost= |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.Cliche, Andre: Ultralight Aircraft Shopper's Guide 8th Edition, page G-2 Cybair Limited Publishing, 2001. {{ISBN|0-9680628-1-4}}
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.{{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}}{{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}}
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.Purdy, Don: AeroCrafter - Homebuilt Aircraft Sourcebook, page 69. BAI Communications. {{ISBN|0-9636409-4-1}}
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.
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.
;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.
;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.
Applications
Specifications (540-L70 aircraft engine)
{{pistonspecs|
|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
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