# Five-stroke engine > Mediated Wiki article. Canonical URL: https://mediated.wiki/source/Five-stroke_engine > Markdown URL: https://mediated.wiki/source/Five-stroke_engine.md > Source: https://en.wikipedia.org/wiki/Five-stroke_engine > Source revision: 1292742266 > License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) {{Short description|Conceptual engine}} The '''five-stroke engine''' is a [compound internal combustion engine](/source/compound_internal_combustion_engine) patented by Gerhard Schmitz in 2000.[https://patents.google.com/patent/US6553977 Google Patents, Five-stroke internal combustion engine, US 6553977 B2, filled Oct 26, 2001] == Concept == The goal of the five-stroke engine is to achieve higher [efficiency](/source/Thermal_efficiency) than a [four-stroke engine](/source/four-stroke_engine). In order to increase efficiency, a secondary cylinder is added as an expansion processor to extract more energy from the fuel. Schmitz's concept engine uses two primary "high pressure" cylinders with standard four-stroke power cycles, in addition to a larger secondary "low pressure" expansion cylinder. The hot [exhaust gas](/source/exhaust_gas) from the two primary cylinders is fed into the secondary cylinder, halving the volume of gases in the primary cylinders after combustion. This concept is similar to that of [compound steam engine](/source/compound_steam_engine)s, which expand steam in high pressure cylinders before exhausting it into low-pressure cylinders in order to extract more energy from the steam. In 1879, [Nicolaus Otto](/source/Nicolaus_Otto) built a 5-stroke engine which was commercially produced, but suffered from poor performance.{{Cite journal |last=Suzuki |first=Takashi |date=May 1997 |title=The Romance of Engines |url=http://dx.doi.org/10.4271/r-188 |journal= |pages=87–93 |doi=10.4271/r-188 |doi-access=free|url-access=subscription }} Two Spanish patents (ES0156621, F Jimeno-Cataneo, 1942; and ES0433850, C Ubierna-Laciana, 1975) describe 5-stroke engines identical to that of Schmitz's design, this engine had a fellowship to Burgundy University to be studied. J.W. Eisenhuth patented an 'air and gas engine' with double expansion (US640890, 1900). A car with this engine was in the [Harrah Collection](/source/The_Harrah_Collection), though its fate after the collection was dismantled is unknown. In Schmitz's design, the [compression ratio](/source/compression_ratio) of the low pressure expansion cylinder is adjustable to achieve an optimal expansion ratio, regardless of the primary cylinders' compression ratio. The prototype has demonstrated an approximately 10% decrease in fuel consumption over a standard gas engine.{{Cite web |url=http://www.ilmor.co.uk/capabilities/5-stroke-engine |title=Ilmor, 5 Stroke Engine |access-date=2017-01-30 |archive-date=2017-03-13 |archive-url=https://web.archive.org/web/20170313160448/http://www.ilmor.co.uk/capabilities/5-stroke-engine |url-status=dead }}[https://www.youtube.com/watch?v=u0uPmrSRM7w Five stroke engine animation]{{Cite web |url=http://www.5-stroke-engine.com/en/Prinzip.html |title=5-stroke-engine.com, The five-stroke concept – ingeniously simple, simply ingenious |access-date=2017-01-30 |archive-date=2015-08-11 |archive-url=https://web.archive.org/web/20150811193639/http://5-stroke-engine.com/en/Prinzip.html |url-status=dead }}[http://www.autoevolution.com/news/five-stroke-engine-works-and-might-enter-production-video-87083.html autoevolution.com, Five-Stroke Engine Works and Might Enter Production. 26 Sep 2014, by Gabriel Brindusescu][http://thekneeslider.com/ilmor-5-stroke-engine-700cc-turbo-3-cylinder-130-bhp/ Ilmor 5 Stroke Engine – 700cc Turbo 3 Cylinder – 130 bhp, Better Mileage, Less Weight, By Paul Crowe] The operation of a 5-stroke SI engine is as follows:
'''1''' – Induction
'''2''' – Compression
'''3''' – Power
'''4''' – Initial exhaust/re-expansion
'''5''' – Final exhaust == Prototype == {{More citations needed|section|date=March 2024}} Schmitz's concept was being developed by [Ilmor](/source/Ilmor). Ilmor's prototype, intended for [motorcycle](/source/motorcycle) use and consisting of 2 primary cylinders and 1 secondary cylinder, uses a solid [cylinder block](/source/cylinder_block) with electrically driven [oil](/source/Motor_oil) and [water](/source/Water_cooling) [pump](/source/pump)s, two [overhead camshaft](/source/overhead_camshaft)s with standard [poppet valve](/source/poppet_valve)s, and [turbocharging](/source/Turbocharger). Its displacement is {{Convert|700|cc|cuin|abbr=unit}} without the secondary cylinder and {{Convert|1478|cc|cuin|abbr=unit}} in total, and it can produce {{Convert|130|hp|kW|abbr=unit}} at 7,000 rpm and {{Convert|166|Nm|lbft|abbr=unit}} at 5,000 rpm. ==See also== {{colbegin}} * [Rotary engine](/source/Pistonless_rotary_engine) * [Stirling engine](/source/Stirling_engine) * [Stroke (engine)](/source/Stroke_(engine)) ** [Two- and four-stroke engines](/source/Two-_and_four-stroke_engines) ** [Two-stroke engine](/source/Two-stroke_engine) ** [Four-stroke engine](/source/Four-stroke_engine) ** [Six-stroke engine](/source/Six-stroke_engine) * [Thermodynamic cycle](/source/Thermodynamic_cycle) ** [Atkinson cycle](/source/Atkinson_cycle) ** [Miller cycle](/source/Miller_cycle) {{colend}} ==References== {{Reflist}} ==External links== *[https://www.youtube.com/watch?v=GaTj15g6L9c Four stroke engine animation] *{{usurped|1=[https://web.archive.org/web/20170625160053/http://www.animatedpiston.com/ Detailed Engine Animations]}} *[http://auto.howstuffworks.com/engine.htm How Car Engines Work] *[http://www.animatedengines.com/otto.shtml Animated Engines, four stroke] {{Webarchive|url=https://web.archive.org/web/20111110171749/http://www.animatedengines.com/otto.shtml |date=2011-11-10 }}, another explanation of the four-stroke engine. *[http://commons.wikimedia.org/wiki/File:New4stroke.gif New 4 stroke] {{Piston engine configurations}} {{Aircraft piston engine components}} Category:Internal combustion piston engines --- Adapted from the Wikipedia article [Five-stroke engine](https://en.wikipedia.org/wiki/Five-stroke_engine) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Five-stroke_engine?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.