CINXE.COM

<!DOCTYPE html> <html class="client-nojs vector-feature-language-in-header-enabled vector-feature-language-in-main-page-header-disabled vector-feature-sticky-header-disabled vector-feature-page-tools-pinned-disabled vector-feature-toc-pinned-clientpref-1 vector-feature-main-menu-pinned-disabled vector-feature-limited-width-clientpref-1 vector-feature-limited-width-content-enabled vector-feature-custom-font-size-clientpref-1 vector-feature-appearance-pinned-clientpref-1 vector-feature-night-mode-enabled skin-theme-clientpref-day vector-toc-available" lang="en" dir="ltr"> <head> <meta charset="UTF-8"> <title>Stroke ratio - Wikipedia</title> <script>(function(){var className="client-js vector-feature-language-in-header-enabled vector-feature-language-in-main-page-header-disabled vector-feature-sticky-header-disabled vector-feature-page-tools-pinned-disabled vector-feature-toc-pinned-clientpref-1 vector-feature-main-menu-pinned-disabled vector-feature-limited-width-clientpref-1 vector-feature-limited-width-content-enabled vector-feature-custom-font-size-clientpref-1 vector-feature-appearance-pinned-clientpref-1 vector-feature-night-mode-enabled skin-theme-clientpref-day vector-toc-available";var cookie=document.cookie.match(/(?:^|; )enwikimwclientpreferences=([^;]+)/);if(cookie){cookie[1].split('%2C').forEach(function(pref){className=className.replace(new RegExp('(^| )'+pref.replace(/-clientpref-\w+$|[^\w-]+/g,'')+'-clientpref-\\w+( |$)'),'$1'+pref+'$2');});}document.documentElement.className=className;}());RLCONF={"wgBreakFrames":false,"wgSeparatorTransformTable":["",""],"wgDigitTransformTable":["",""],"wgDefaultDateFormat":"dmy", "wgMonthNames":["","January","February","March","April","May","June","July","August","September","October","November","December"],"wgRequestId":"34651312-d91b-4c7d-9d2d-ccf844372121","wgCanonicalNamespace":"","wgCanonicalSpecialPageName":false,"wgNamespaceNumber":0,"wgPageName":"Stroke_ratio","wgTitle":"Stroke ratio","wgCurRevisionId":1258125692,"wgRevisionId":1258125692,"wgArticleId":2841656,"wgIsArticle":true,"wgIsRedirect":false,"wgAction":"view","wgUserName":null,"wgUserGroups":["*"],"wgCategories":["All articles with unsourced statements","Articles with unsourced statements from November 2023","Articles with short description","Short description is different from Wikidata","Articles needing additional references from August 2009","All articles needing additional references","Use dmy dates from April 2022","Articles with too many examples from November 2023","All articles with too many examples","Wikipedia articles with style issues from November 2023", "All Wikipedia articles needing clarification","Wikipedia articles needing clarification from November 2023","Commons category link is locally defined","Engine technology","Piston engines","Engineering ratios"],"wgPageViewLanguage":"en","wgPageContentLanguage":"en","wgPageContentModel":"wikitext","wgRelevantPageName":"Stroke_ratio","wgRelevantArticleId":2841656,"wgIsProbablyEditable":true,"wgRelevantPageIsProbablyEditable":true,"wgRestrictionEdit":[],"wgRestrictionMove":[],"wgRedirectedFrom":"Undersquare","wgNoticeProject":"wikipedia","wgCiteReferencePreviewsActive":false,"wgFlaggedRevsParams":{"tags":{"status":{"levels":1}}},"wgMediaViewerOnClick":true,"wgMediaViewerEnabledByDefault":true,"wgPopupsFlags":0,"wgVisualEditor":{"pageLanguageCode":"en","pageLanguageDir":"ltr","pageVariantFallbacks":"en"},"wgMFDisplayWikibaseDescriptions":{"search":true,"watchlist":true,"tagline":false,"nearby":true},"wgWMESchemaEditAttemptStepOversample":false,"wgWMEPageLength":20000, "wgInternalRedirectTargetUrl":"/wiki/Stroke_ratio#Undersquare","wgRelatedArticlesCompat":[],"wgEditSubmitButtonLabelPublish":true,"wgULSPosition":"interlanguage","wgULSisCompactLinksEnabled":false,"wgVector2022LanguageInHeader":true,"wgULSisLanguageSelectorEmpty":false,"wgWikibaseItemId":"Q844463","wgCheckUserClientHintsHeadersJsApi":["brands","architecture","bitness","fullVersionList","mobile","model","platform","platformVersion"],"GEHomepageSuggestedEditsEnableTopics":true,"wgGETopicsMatchModeEnabled":false,"wgGEStructuredTaskRejectionReasonTextInputEnabled":false,"wgGELevelingUpEnabledForUser":false};RLSTATE={"ext.globalCssJs.user.styles":"ready","site.styles":"ready","user.styles":"ready","ext.globalCssJs.user":"ready","user":"ready","user.options":"loading","ext.cite.styles":"ready","skins.vector.search.codex.styles":"ready","skins.vector.styles":"ready","skins.vector.icons":"ready","jquery.makeCollapsible.styles":"ready","ext.wikimediamessages.styles":"ready", "ext.visualEditor.desktopArticleTarget.noscript":"ready","ext.uls.interlanguage":"ready","wikibase.client.init":"ready","ext.wikimediaBadges":"ready"};RLPAGEMODULES=["mediawiki.action.view.redirect","ext.cite.ux-enhancements","mediawiki.page.media","site","mediawiki.page.ready","jquery.makeCollapsible","mediawiki.toc","skins.vector.js","ext.centralNotice.geoIP","ext.centralNotice.startUp","ext.gadget.ReferenceTooltips","ext.gadget.switcher","ext.urlShortener.toolbar","ext.centralauth.centralautologin","mmv.bootstrap","ext.popups","ext.visualEditor.desktopArticleTarget.init","ext.visualEditor.targetLoader","ext.echo.centralauth","ext.eventLogging","ext.wikimediaEvents","ext.navigationTiming","ext.uls.interface","ext.cx.eventlogging.campaigns","ext.cx.uls.quick.actions","wikibase.client.vector-2022","ext.checkUser.clientHints","ext.growthExperiments.SuggestedEditSession"];</script> <script>(RLQ=window.RLQ||[]).push(function(){mw.loader.impl(function(){return["user.options@12s5i",function($,jQuery,require,module){mw.user.tokens.set({"patrolToken":"+\\","watchToken":"+\\","csrfToken":"+\\"}); }];});});</script> <link rel="stylesheet" href="/w/load.php?lang=en&modules=ext.cite.styles%7Cext.uls.interlanguage%7Cext.visualEditor.desktopArticleTarget.noscript%7Cext.wikimediaBadges%7Cext.wikimediamessages.styles%7Cjquery.makeCollapsible.styles%7Cskins.vector.icons%2Cstyles%7Cskins.vector.search.codex.styles%7Cwikibase.client.init&only=styles&skin=vector-2022"> <script async="" src="/w/load.php?lang=en&modules=startup&only=scripts&raw=1&skin=vector-2022"></script> <meta name="ResourceLoaderDynamicStyles" content=""> <link rel="stylesheet" href="/w/load.php?lang=en&modules=site.styles&only=styles&skin=vector-2022"> <meta name="generator" content="MediaWiki 1.44.0-wmf.6"> <meta name="referrer" content="origin"> <meta name="referrer" content="origin-when-cross-origin"> <meta name="robots" content="max-image-preview:standard"> <meta name="format-detection" content="telephone=no"> <meta property="og:image" content="https://upload.wikimedia.org/wikipedia/commons/b/bf/Bore_Stroke_Ratio_Animation.gif"> <meta property="og:image:width" content="1200"> <meta property="og:image:height" content="1463"> <meta property="og:image" content="https://upload.wikimedia.org/wikipedia/commons/b/bf/Bore_Stroke_Ratio_Animation.gif"> <meta property="og:image:width" content="800"> <meta property="og:image:height" content="975"> <meta property="og:image:width" content="640"> <meta property="og:image:height" content="780"> <meta name="viewport" content="width=1120"> <meta property="og:title" content="Stroke ratio - Wikipedia"> <meta property="og:type" content="website"> <link rel="preconnect" href="//upload.wikimedia.org"> <link rel="alternate" media="only screen and (max-width: 640px)" href="//en.m.wikipedia.org/wiki/Stroke_ratio#Undersquare"> <link rel="alternate" type="application/x-wiki" title="Edit this page" href="/w/index.php?title=Stroke_ratio&action=edit"> <link rel="apple-touch-icon" href="/static/apple-touch/wikipedia.png"> <link rel="icon" href="/static/favicon/wikipedia.ico"> <link rel="search" type="application/opensearchdescription+xml" href="/w/rest.php/v1/search" title="Wikipedia (en)"> <link rel="EditURI" type="application/rsd+xml" href="//en.wikipedia.org/w/api.php?action=rsd"> <link rel="canonical" href="https://en.wikipedia.org/wiki/Stroke_ratio#Undersquare"> <link rel="license" href="https://creativecommons.org/licenses/by-sa/4.0/deed.en"> <link rel="alternate" type="application/atom+xml" title="Wikipedia Atom feed" href="/w/index.php?title=Special:RecentChanges&feed=atom"> <link rel="dns-prefetch" href="//meta.wikimedia.org" /> <link rel="dns-prefetch" href="login.wikimedia.org"> </head> <body class="skin--responsive skin-vector skin-vector-search-vue mediawiki ltr sitedir-ltr mw-hide-empty-elt ns-0 ns-subject mw-editable page-Stroke_ratio rootpage-Stroke_ratio skin-vector-2022 action-view"><a class="mw-jump-link" href="#bodyContent">Jump to content</a> <div class="vector-header-container"> <header class="vector-header mw-header"> <div class="vector-header-start"> <nav class="vector-main-menu-landmark" aria-label="Site"> <div id="vector-main-menu-dropdown" class="vector-dropdown vector-main-menu-dropdown vector-button-flush-left vector-button-flush-right" > <input type="checkbox" id="vector-main-menu-dropdown-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-main-menu-dropdown" class="vector-dropdown-checkbox " aria-label="Main menu" > <label id="vector-main-menu-dropdown-label" for="vector-main-menu-dropdown-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only " aria-hidden="true" ><span class="vector-icon mw-ui-icon-menu mw-ui-icon-wikimedia-menu"></span> <span class="vector-dropdown-label-text">Main menu</span> </label> <div class="vector-dropdown-content"> <div id="vector-main-menu-unpinned-container" class="vector-unpinned-container"> <div id="vector-main-menu" class="vector-main-menu vector-pinnable-element"> <div class="vector-pinnable-header vector-main-menu-pinnable-header vector-pinnable-header-unpinned" data-feature-name="main-menu-pinned" data-pinnable-element-id="vector-main-menu" data-pinned-container-id="vector-main-menu-pinned-container" data-unpinned-container-id="vector-main-menu-unpinned-container" > <div class="vector-pinnable-header-label">Main menu</div> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-pin-button" data-event-name="pinnable-header.vector-main-menu.pin">move to sidebar</button> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-unpin-button" data-event-name="pinnable-header.vector-main-menu.unpin">hide</button> </div> <div id="p-navigation" class="vector-menu mw-portlet mw-portlet-navigation" > <div class="vector-menu-heading"> Navigation </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="n-mainpage-description" class="mw-list-item"><a href="/wiki/Main_Page" title="Visit the main page [z]" accesskey="z"><span>Main page</span></a></li><li id="n-contents" class="mw-list-item"><a href="/wiki/Wikipedia:Contents" title="Guides to browsing Wikipedia"><span>Contents</span></a></li><li id="n-currentevents" class="mw-list-item"><a href="/wiki/Portal:Current_events" title="Articles related to current events"><span>Current events</span></a></li><li id="n-randompage" class="mw-list-item"><a href="/wiki/Special:Random" title="Visit a randomly selected article [x]" accesskey="x"><span>Random article</span></a></li><li id="n-aboutsite" class="mw-list-item"><a href="/wiki/Wikipedia:About" title="Learn about Wikipedia and how it works"><span>About Wikipedia</span></a></li><li id="n-contactpage" class="mw-list-item"><a href="//en.wikipedia.org/wiki/Wikipedia:Contact_us" title="How to contact Wikipedia"><span>Contact us</span></a></li> </ul> </div> </div> <div id="p-interaction" class="vector-menu mw-portlet mw-portlet-interaction" > <div class="vector-menu-heading"> Contribute </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="n-help" class="mw-list-item"><a href="/wiki/Help:Contents" title="Guidance on how to use and edit Wikipedia"><span>Help</span></a></li><li id="n-introduction" class="mw-list-item"><a href="/wiki/Help:Introduction" title="Learn how to edit Wikipedia"><span>Learn to edit</span></a></li><li id="n-portal" class="mw-list-item"><a href="/wiki/Wikipedia:Community_portal" title="The hub for editors"><span>Community portal</span></a></li><li id="n-recentchanges" class="mw-list-item"><a href="/wiki/Special:RecentChanges" title="A list of recent changes to Wikipedia [r]" accesskey="r"><span>Recent changes</span></a></li><li id="n-upload" class="mw-list-item"><a href="/wiki/Wikipedia:File_upload_wizard" title="Add images or other media for use on Wikipedia"><span>Upload file</span></a></li> </ul> </div> </div> </div> </div> </div> </div> </nav> <a href="/wiki/Main_Page" class="mw-logo"> <img class="mw-logo-icon" src="/static/images/icons/wikipedia.png" alt="" aria-hidden="true" height="50" width="50"> <span class="mw-logo-container skin-invert"> <img class="mw-logo-wordmark" alt="Wikipedia" src="/static/images/mobile/copyright/wikipedia-wordmark-en.svg" style="width: 7.5em; height: 1.125em;"> <img class="mw-logo-tagline" alt="The Free Encyclopedia" src="/static/images/mobile/copyright/wikipedia-tagline-en.svg" width="117" height="13" style="width: 7.3125em; height: 0.8125em;"> </span> </a> </div> <div class="vector-header-end"> <div id="p-search" role="search" class="vector-search-box-vue vector-search-box-collapses vector-search-box-show-thumbnail vector-search-box-auto-expand-width vector-search-box"> <a href="/wiki/Special:Search" class="cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only search-toggle" title="Search Wikipedia [f]" accesskey="f"><span class="vector-icon mw-ui-icon-search mw-ui-icon-wikimedia-search"></span> <span>Search</span> </a> <div class="vector-typeahead-search-container"> <div class="cdx-typeahead-search cdx-typeahead-search--show-thumbnail cdx-typeahead-search--auto-expand-width"> <form action="/w/index.php" id="searchform" class="cdx-search-input cdx-search-input--has-end-button"> <div id="simpleSearch" class="cdx-search-input__input-wrapper" data-search-loc="header-moved"> <div class="cdx-text-input cdx-text-input--has-start-icon"> <input class="cdx-text-input__input" type="search" name="search" placeholder="Search Wikipedia" aria-label="Search Wikipedia" autocapitalize="sentences" title="Search Wikipedia [f]" accesskey="f" id="searchInput" > <span class="cdx-text-input__icon cdx-text-input__start-icon"></span> </div> <input type="hidden" name="title" value="Special:Search"> </div> <button class="cdx-button cdx-search-input__end-button">Search</button> </form> </div> </div> </div> <nav class="vector-user-links vector-user-links-wide" aria-label="Personal tools"> <div class="vector-user-links-main"> <div id="p-vector-user-menu-preferences" class="vector-menu mw-portlet emptyPortlet" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> </ul> </div> </div> <div id="p-vector-user-menu-userpage" class="vector-menu mw-portlet emptyPortlet" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> </ul> </div> </div> <nav class="vector-appearance-landmark" aria-label="Appearance"> <div id="vector-appearance-dropdown" class="vector-dropdown " title="Change the appearance of the page's font size, width, and color" > <input type="checkbox" id="vector-appearance-dropdown-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-appearance-dropdown" class="vector-dropdown-checkbox " aria-label="Appearance" > <label id="vector-appearance-dropdown-label" for="vector-appearance-dropdown-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only " aria-hidden="true" ><span class="vector-icon mw-ui-icon-appearance mw-ui-icon-wikimedia-appearance"></span> <span class="vector-dropdown-label-text">Appearance</span> </label> <div class="vector-dropdown-content"> <div id="vector-appearance-unpinned-container" class="vector-unpinned-container"> </div> </div> </div> </nav> <div id="p-vector-user-menu-notifications" class="vector-menu mw-portlet emptyPortlet" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> </ul> </div> </div> <div id="p-vector-user-menu-overflow" class="vector-menu mw-portlet" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="pt-sitesupport-2" class="user-links-collapsible-item mw-list-item user-links-collapsible-item"><a data-mw="interface" href="https://donate.wikimedia.org/?wmf_source=donate&wmf_medium=sidebar&wmf_campaign=en.wikipedia.org&uselang=en" class=""><span>Donate</span></a> </li> <li id="pt-createaccount-2" class="user-links-collapsible-item mw-list-item user-links-collapsible-item"><a data-mw="interface" href="/w/index.php?title=Special:CreateAccount&returnto=Stroke+ratio" title="You are encouraged to create an account and log in; however, it is not mandatory" class=""><span>Create account</span></a> </li> <li id="pt-login-2" class="user-links-collapsible-item mw-list-item user-links-collapsible-item"><a data-mw="interface" href="/w/index.php?title=Special:UserLogin&returnto=Stroke+ratio" title="You're encouraged to log in; however, it's not mandatory. [o]" accesskey="o" class=""><span>Log in</span></a> </li> </ul> </div> </div> </div> <div id="vector-user-links-dropdown" class="vector-dropdown vector-user-menu vector-button-flush-right vector-user-menu-logged-out" title="Log in and more options" > <input type="checkbox" id="vector-user-links-dropdown-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-user-links-dropdown" class="vector-dropdown-checkbox " aria-label="Personal tools" > <label id="vector-user-links-dropdown-label" for="vector-user-links-dropdown-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only " aria-hidden="true" ><span class="vector-icon mw-ui-icon-ellipsis mw-ui-icon-wikimedia-ellipsis"></span> <span class="vector-dropdown-label-text">Personal tools</span> </label> <div class="vector-dropdown-content"> <div id="p-personal" class="vector-menu mw-portlet mw-portlet-personal user-links-collapsible-item" title="User menu" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="pt-sitesupport" class="user-links-collapsible-item mw-list-item"><a href="https://donate.wikimedia.org/?wmf_source=donate&wmf_medium=sidebar&wmf_campaign=en.wikipedia.org&uselang=en"><span>Donate</span></a></li><li id="pt-createaccount" class="user-links-collapsible-item mw-list-item"><a href="/w/index.php?title=Special:CreateAccount&returnto=Stroke+ratio" title="You are encouraged to create an account and log in; however, it is not mandatory"><span class="vector-icon mw-ui-icon-userAdd mw-ui-icon-wikimedia-userAdd"></span> <span>Create account</span></a></li><li id="pt-login" class="user-links-collapsible-item mw-list-item"><a href="/w/index.php?title=Special:UserLogin&returnto=Stroke+ratio" title="You're encouraged to log in; however, it's not mandatory. [o]" accesskey="o"><span class="vector-icon mw-ui-icon-logIn mw-ui-icon-wikimedia-logIn"></span> <span>Log in</span></a></li> </ul> </div> </div> <div id="p-user-menu-anon-editor" class="vector-menu mw-portlet mw-portlet-user-menu-anon-editor" > <div class="vector-menu-heading"> Pages for logged out editors <a href="/wiki/Help:Introduction" aria-label="Learn more about editing"><span>learn more</span></a> </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="pt-anoncontribs" class="mw-list-item"><a href="/wiki/Special:MyContributions" title="A list of edits made from this IP address [y]" accesskey="y"><span>Contributions</span></a></li><li id="pt-anontalk" class="mw-list-item"><a href="/wiki/Special:MyTalk" title="Discussion about edits from this IP address [n]" accesskey="n"><span>Talk</span></a></li> </ul> </div> </div> </div> </div> </nav> </div> </header> </div> <div class="mw-page-container"> <div class="mw-page-container-inner"> <div class="vector-sitenotice-container"> <div id="siteNotice"></div> </div> <div class="vector-column-start"> <div class="vector-main-menu-container"> <div id="mw-navigation"> <nav id="mw-panel" class="vector-main-menu-landmark" aria-label="Site"> <div id="vector-main-menu-pinned-container" class="vector-pinned-container"> </div> </nav> </div> </div> <div class="vector-sticky-pinned-container"> <nav id="mw-panel-toc" aria-label="Contents" data-event-name="ui.sidebar-toc" class="mw-table-of-contents-container vector-toc-landmark"> <div id="vector-toc-pinned-container" class="vector-pinned-container"> <div id="vector-toc" class="vector-toc vector-pinnable-element"> <div class="vector-pinnable-header vector-toc-pinnable-header vector-pinnable-header-pinned" data-feature-name="toc-pinned" data-pinnable-element-id="vector-toc" > <h2 class="vector-pinnable-header-label">Contents</h2> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-pin-button" data-event-name="pinnable-header.vector-toc.pin">move to sidebar</button> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-unpin-button" data-event-name="pinnable-header.vector-toc.unpin">hide</button> </div> <ul class="vector-toc-contents" id="mw-panel-toc-list"> <li id="toc-mw-content-text" class="vector-toc-list-item vector-toc-level-1"> <a href="#" class="vector-toc-link"> <div class="vector-toc-text">(Top)</div> </a> </li> <li id="toc-Conventions" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Conventions"> <div class="vector-toc-text"> <span class="vector-toc-numb">1</span> <span>Conventions</span> </div> </a> <button aria-controls="toc-Conventions-sublist" class="cdx-button cdx-button--weight-quiet cdx-button--icon-only vector-toc-toggle"> <span class="vector-icon mw-ui-icon-wikimedia-expand"></span> <span>Toggle Conventions subsection</span> </button> <ul id="toc-Conventions-sublist" class="vector-toc-list"> <li id="toc-Bore/stroke_ratio" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Bore/stroke_ratio"> <div class="vector-toc-text"> <span class="vector-toc-numb">1.1</span> <span>Bore/stroke ratio</span> </div> </a> <ul id="toc-Bore/stroke_ratio-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> <li id="toc-Square,_oversquare_and_undersquare_engines" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Square,_oversquare_and_undersquare_engines"> <div class="vector-toc-text"> <span class="vector-toc-numb">2</span> <span>Square, oversquare and undersquare engines</span> </div> </a> <button aria-controls="toc-Square,_oversquare_and_undersquare_engines-sublist" class="cdx-button cdx-button--weight-quiet cdx-button--icon-only vector-toc-toggle"> <span class="vector-icon mw-ui-icon-wikimedia-expand"></span> <span>Toggle Square, oversquare and undersquare engines subsection</span> </button> <ul id="toc-Square,_oversquare_and_undersquare_engines-sublist" class="vector-toc-list"> <li id="toc-Square" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Square"> <div class="vector-toc-text"> <span class="vector-toc-numb">2.1</span> <span>Square</span> </div> </a> <ul id="toc-Square-sublist" class="vector-toc-list"> <li id="toc-Square_engine_examples" class="vector-toc-list-item vector-toc-level-3"> <a class="vector-toc-link" href="#Square_engine_examples"> <div class="vector-toc-text"> <span class="vector-toc-numb">2.1.1</span> <span>Square engine examples</span> </div> </a> <ul id="toc-Square_engine_examples-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> <li id="toc-Oversquare" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Oversquare"> <div class="vector-toc-text"> <span class="vector-toc-numb">2.2</span> <span>Oversquare</span> </div> </a> <ul id="toc-Oversquare-sublist" class="vector-toc-list"> <li id="toc-Oversquare_engine_examples" class="vector-toc-list-item vector-toc-level-3"> <a class="vector-toc-link" href="#Oversquare_engine_examples"> <div class="vector-toc-text"> <span class="vector-toc-numb">2.2.1</span> <span>Oversquare engine examples</span> </div> </a> <ul id="toc-Oversquare_engine_examples-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> <li id="toc-Undersquare" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Undersquare"> <div class="vector-toc-text"> <span class="vector-toc-numb">2.3</span> <span>Undersquare</span> </div> </a> <ul id="toc-Undersquare-sublist" class="vector-toc-list"> <li id="toc-Undersquare_engine_examples" class="vector-toc-list-item vector-toc-level-3"> <a class="vector-toc-link" href="#Undersquare_engine_examples"> <div class="vector-toc-text"> <span class="vector-toc-numb">2.3.1</span> <span>Undersquare engine examples</span> </div> </a> <ul id="toc-Undersquare_engine_examples-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> </ul> </li> <li id="toc-Notes" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Notes"> <div class="vector-toc-text"> <span class="vector-toc-numb">3</span> <span>Notes</span> </div> </a> <ul id="toc-Notes-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-References" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#References"> <div class="vector-toc-text"> <span class="vector-toc-numb">4</span> <span>References</span> </div> </a> <ul id="toc-References-sublist" class="vector-toc-list"> </ul> </li> </ul> </div> </div> </nav> </div> </div> <div class="mw-content-container"> <main id="content" class="mw-body"> <header class="mw-body-header vector-page-titlebar"> <nav aria-label="Contents" class="vector-toc-landmark"> <div id="vector-page-titlebar-toc" class="vector-dropdown vector-page-titlebar-toc vector-button-flush-left" > <input type="checkbox" id="vector-page-titlebar-toc-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-page-titlebar-toc" class="vector-dropdown-checkbox " aria-label="Toggle the table of contents" > <label id="vector-page-titlebar-toc-label" for="vector-page-titlebar-toc-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only " aria-hidden="true" ><span class="vector-icon mw-ui-icon-listBullet mw-ui-icon-wikimedia-listBullet"></span> <span class="vector-dropdown-label-text">Toggle the table of contents</span> </label> <div class="vector-dropdown-content"> <div id="vector-page-titlebar-toc-unpinned-container" class="vector-unpinned-container"> </div> </div> </div> </nav> <h1 id="firstHeading" class="firstHeading mw-first-heading"><span class="mw-page-title-main">Stroke ratio</span></h1> <div id="p-lang-btn" class="vector-dropdown mw-portlet mw-portlet-lang" > <input type="checkbox" id="p-lang-btn-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-p-lang-btn" class="vector-dropdown-checkbox mw-interlanguage-selector" aria-label="Go to an article in another language. Available in 6 languages" > <label id="p-lang-btn-label" for="p-lang-btn-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--action-progressive mw-portlet-lang-heading-6" aria-hidden="true" ><span class="vector-icon mw-ui-icon-language-progressive mw-ui-icon-wikimedia-language-progressive"></span> <span class="vector-dropdown-label-text">6 languages</span> </label> <div class="vector-dropdown-content"> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li class="interlanguage-link interwiki-de mw-list-item"><a href="https://de.wikipedia.org/wiki/Hubverh%C3%A4ltnis" title="Hubverhältnis – German" lang="de" hreflang="de" data-title="Hubverhältnis" data-language-autonym="Deutsch" data-language-local-name="German" class="interlanguage-link-target"><span>Deutsch</span></a></li><li class="interlanguage-link interwiki-es mw-list-item"><a href="https://es.wikipedia.org/wiki/Relaci%C3%B3n_di%C3%A1metro/carrera" title="Relación diámetro/carrera – Spanish" lang="es" hreflang="es" data-title="Relación diámetro/carrera" data-language-autonym="Español" data-language-local-name="Spanish" class="interlanguage-link-target"><span>Español</span></a></li><li class="interlanguage-link interwiki-it mw-list-item"><a href="https://it.wikipedia.org/wiki/Rapporto_alesaggio/corsa" title="Rapporto alesaggio/corsa – Italian" lang="it" hreflang="it" data-title="Rapporto alesaggio/corsa" data-language-autonym="Italiano" data-language-local-name="Italian" class="interlanguage-link-target"><span>Italiano</span></a></li><li class="interlanguage-link interwiki-nl mw-list-item"><a href="https://nl.wikipedia.org/wiki/Boring-slagverhouding" title="Boring-slagverhouding – Dutch" lang="nl" hreflang="nl" data-title="Boring-slagverhouding" data-language-autonym="Nederlands" data-language-local-name="Dutch" class="interlanguage-link-target"><span>Nederlands</span></a></li><li class="interlanguage-link interwiki-ja mw-list-item"><a href="https://ja.wikipedia.org/wiki/%E3%83%9C%E3%82%A2%E3%82%B9%E3%83%88%E3%83%AD%E3%83%BC%E3%82%AF%E6%AF%94" title="ボアストローク比 – Japanese" lang="ja" hreflang="ja" data-title="ボアストローク比" data-language-autonym="日本語" data-language-local-name="Japanese" class="interlanguage-link-target"><span>日本語</span></a></li><li class="interlanguage-link interwiki-fi mw-list-item"><a href="https://fi.wikipedia.org/wiki/Iskusuhde" title="Iskusuhde – Finnish" lang="fi" hreflang="fi" data-title="Iskusuhde" data-language-autonym="Suomi" data-language-local-name="Finnish" class="interlanguage-link-target"><span>Suomi</span></a></li> </ul> <div class="after-portlet after-portlet-lang"><span class="wb-langlinks-edit wb-langlinks-link"><a href="https://www.wikidata.org/wiki/Special:EntityPage/Q844463#sitelinks-wikipedia" title="Edit interlanguage links" class="wbc-editpage">Edit links</a></span></div> </div> </div> </div> </header> <div class="vector-page-toolbar"> <div class="vector-page-toolbar-container"> <div id="left-navigation"> <nav aria-label="Namespaces"> <div id="p-associated-pages" class="vector-menu vector-menu-tabs mw-portlet mw-portlet-associated-pages" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="ca-nstab-main" class="selected vector-tab-noicon mw-list-item"><a href="/wiki/Stroke_ratio" title="View the content page [c]" accesskey="c"><span>Article</span></a></li><li id="ca-talk" class="vector-tab-noicon mw-list-item"><a href="/wiki/Talk:Stroke_ratio" rel="discussion" title="Discuss improvements to the content page [t]" accesskey="t"><span>Talk</span></a></li> </ul> </div> </div> <div id="vector-variants-dropdown" class="vector-dropdown emptyPortlet" > <input type="checkbox" id="vector-variants-dropdown-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-variants-dropdown" class="vector-dropdown-checkbox " aria-label="Change language variant" > <label id="vector-variants-dropdown-label" for="vector-variants-dropdown-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet" aria-hidden="true" ><span class="vector-dropdown-label-text">English</span> </label> <div class="vector-dropdown-content"> <div id="p-variants" class="vector-menu mw-portlet mw-portlet-variants emptyPortlet" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> </ul> </div> </div> </div> </div> </nav> </div> <div id="right-navigation" class="vector-collapsible"> <nav aria-label="Views"> <div id="p-views" class="vector-menu vector-menu-tabs mw-portlet mw-portlet-views" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="ca-view" class="selected vector-tab-noicon mw-list-item"><a href="/wiki/Stroke_ratio"><span>Read</span></a></li><li id="ca-edit" class="vector-tab-noicon mw-list-item"><a href="/w/index.php?title=Stroke_ratio&action=edit" title="Edit this page [e]" accesskey="e"><span>Edit</span></a></li><li id="ca-history" class="vector-tab-noicon mw-list-item"><a href="/w/index.php?title=Stroke_ratio&action=history" title="Past revisions of this page [h]" accesskey="h"><span>View history</span></a></li> </ul> </div> </div> </nav> <nav class="vector-page-tools-landmark" aria-label="Page tools"> <div id="vector-page-tools-dropdown" class="vector-dropdown vector-page-tools-dropdown" > <input type="checkbox" id="vector-page-tools-dropdown-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-page-tools-dropdown" class="vector-dropdown-checkbox " aria-label="Tools" > <label id="vector-page-tools-dropdown-label" for="vector-page-tools-dropdown-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet" aria-hidden="true" ><span class="vector-dropdown-label-text">Tools</span> </label> <div class="vector-dropdown-content"> <div id="vector-page-tools-unpinned-container" class="vector-unpinned-container"> <div id="vector-page-tools" class="vector-page-tools vector-pinnable-element"> <div class="vector-pinnable-header vector-page-tools-pinnable-header vector-pinnable-header-unpinned" data-feature-name="page-tools-pinned" data-pinnable-element-id="vector-page-tools" data-pinned-container-id="vector-page-tools-pinned-container" data-unpinned-container-id="vector-page-tools-unpinned-container" > <div class="vector-pinnable-header-label">Tools</div> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-pin-button" data-event-name="pinnable-header.vector-page-tools.pin">move to sidebar</button> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-unpin-button" data-event-name="pinnable-header.vector-page-tools.unpin">hide</button> </div> <div id="p-cactions" class="vector-menu mw-portlet mw-portlet-cactions emptyPortlet vector-has-collapsible-items" title="More options" > <div class="vector-menu-heading"> Actions </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="ca-more-view" class="selected vector-more-collapsible-item mw-list-item"><a href="/wiki/Stroke_ratio"><span>Read</span></a></li><li id="ca-more-edit" class="vector-more-collapsible-item mw-list-item"><a href="/w/index.php?title=Stroke_ratio&action=edit" title="Edit this page [e]" accesskey="e"><span>Edit</span></a></li><li id="ca-more-history" class="vector-more-collapsible-item mw-list-item"><a href="/w/index.php?title=Stroke_ratio&action=history"><span>View history</span></a></li> </ul> </div> </div> <div id="p-tb" class="vector-menu mw-portlet mw-portlet-tb" > <div class="vector-menu-heading"> General </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="t-whatlinkshere" class="mw-list-item"><a href="/wiki/Special:WhatLinksHere/Stroke_ratio" title="List of all English Wikipedia pages containing links to this page [j]" accesskey="j"><span>What links here</span></a></li><li id="t-recentchangeslinked" class="mw-list-item"><a href="/wiki/Special:RecentChangesLinked/Stroke_ratio" rel="nofollow" title="Recent changes in pages linked from this page [k]" accesskey="k"><span>Related changes</span></a></li><li id="t-upload" class="mw-list-item"><a href="/wiki/Wikipedia:File_Upload_Wizard" title="Upload files [u]" accesskey="u"><span>Upload file</span></a></li><li id="t-specialpages" class="mw-list-item"><a href="/wiki/Special:SpecialPages" title="A list of all special pages [q]" accesskey="q"><span>Special pages</span></a></li><li id="t-permalink" class="mw-list-item"><a href="/w/index.php?title=Stroke_ratio&oldid=1258125692" title="Permanent link to this revision of this page"><span>Permanent link</span></a></li><li id="t-info" class="mw-list-item"><a href="/w/index.php?title=Stroke_ratio&action=info" title="More information about this page"><span>Page information</span></a></li><li id="t-cite" class="mw-list-item"><a href="/w/index.php?title=Special:CiteThisPage&page=Stroke_ratio&id=1258125692&wpFormIdentifier=titleform" title="Information on how to cite this page"><span>Cite this page</span></a></li><li id="t-urlshortener" class="mw-list-item"><a href="/w/index.php?title=Special:UrlQ%C4%B1sald%C4%B1c%C4%B1s%C4%B1&url=https%3A%2F%2Fen.wikipedia.org%2Fwiki%2FStroke_ratio%23Undersquare"><span>Get shortened URL</span></a></li><li id="t-urlshortener-qrcode" class="mw-list-item"><a href="/w/index.php?title=Special:QrKodu&url=https%3A%2F%2Fen.wikipedia.org%2Fwiki%2FStroke_ratio%23Undersquare"><span>Download QR code</span></a></li> </ul> </div> </div> <div id="p-coll-print_export" class="vector-menu mw-portlet mw-portlet-coll-print_export" > <div class="vector-menu-heading"> Print/export </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="coll-download-as-rl" class="mw-list-item"><a href="/w/index.php?title=Special:DownloadAsPdf&page=Stroke_ratio&action=show-download-screen" title="Download this page as a PDF file"><span>Download as PDF</span></a></li><li id="t-print" class="mw-list-item"><a href="/w/index.php?title=Stroke_ratio&printable=yes" title="Printable version of this page [p]" accesskey="p"><span>Printable version</span></a></li> </ul> </div> </div> <div id="p-wikibase-otherprojects" class="vector-menu mw-portlet mw-portlet-wikibase-otherprojects" > <div class="vector-menu-heading"> In other projects </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li class="wb-otherproject-link wb-otherproject-commons mw-list-item"><a href="https://commons.wikimedia.org/wiki/Category:Internal_combustion_engines" hreflang="en"><span>Wikimedia Commons</span></a></li><li id="t-wikibase" class="wb-otherproject-link wb-otherproject-wikibase-dataitem mw-list-item"><a href="https://www.wikidata.org/wiki/Special:EntityPage/Q844463" title="Structured data on this page hosted by Wikidata [g]" accesskey="g"><span>Wikidata item</span></a></li> </ul> </div> </div> </div> </div> </div> </div> </nav> </div> </div> </div> <div class="vector-column-end"> <div class="vector-sticky-pinned-container"> <nav class="vector-page-tools-landmark" aria-label="Page tools"> <div id="vector-page-tools-pinned-container" class="vector-pinned-container"> </div> </nav> <nav class="vector-appearance-landmark" aria-label="Appearance"> <div id="vector-appearance-pinned-container" class="vector-pinned-container"> <div id="vector-appearance" class="vector-appearance vector-pinnable-element"> <div class="vector-pinnable-header vector-appearance-pinnable-header vector-pinnable-header-pinned" data-feature-name="appearance-pinned" data-pinnable-element-id="vector-appearance" data-pinned-container-id="vector-appearance-pinned-container" data-unpinned-container-id="vector-appearance-unpinned-container" > <div class="vector-pinnable-header-label">Appearance</div> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-pin-button" data-event-name="pinnable-header.vector-appearance.pin">move to sidebar</button> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-unpin-button" data-event-name="pinnable-header.vector-appearance.unpin">hide</button> </div> </div> </div> </nav> </div> </div> <div id="bodyContent" class="vector-body" aria-labelledby="firstHeading" data-mw-ve-target-container> <div class="vector-body-before-content"> <div class="mw-indicators"> </div> <div id="siteSub" class="noprint">From Wikipedia, the free encyclopedia</div> </div> <div id="contentSub"><div id="mw-content-subtitle"><span class="mw-redirectedfrom">(Redirected from <a href="/w/index.php?title=Undersquare&redirect=no" class="mw-redirect" title="Undersquare">Undersquare</a>)</span></div></div> <div id="mw-content-text" class="mw-body-content"><div class="mw-content-ltr mw-parser-output" lang="en" dir="ltr"><div class="shortdescription nomobile noexcerpt noprint searchaux" style="display:none">Mechanical measurement</div> <style data-mw-deduplicate="TemplateStyles:r1251242444">.mw-parser-output .ambox{border:1px solid #a2a9b1;border-left:10px solid #36c;background-color:#fbfbfb;box-sizing:border-box}.mw-parser-output .ambox+link+.ambox,.mw-parser-output .ambox+link+style+.ambox,.mw-parser-output .ambox+link+link+.ambox,.mw-parser-output .ambox+.mw-empty-elt+link+.ambox,.mw-parser-output .ambox+.mw-empty-elt+link+style+.ambox,.mw-parser-output .ambox+.mw-empty-elt+link+link+.ambox{margin-top:-1px}html body.mediawiki .mw-parser-output .ambox.mbox-small-left{margin:4px 1em 4px 0;overflow:hidden;width:238px;border-collapse:collapse;font-size:88%;line-height:1.25em}.mw-parser-output .ambox-speedy{border-left:10px solid #b32424;background-color:#fee7e6}.mw-parser-output .ambox-delete{border-left:10px solid #b32424}.mw-parser-output .ambox-content{border-left:10px solid #f28500}.mw-parser-output .ambox-style{border-left:10px solid #fc3}.mw-parser-output .ambox-move{border-left:10px solid #9932cc}.mw-parser-output .ambox-protection{border-left:10px solid #a2a9b1}.mw-parser-output .ambox .mbox-text{border:none;padding:0.25em 0.5em;width:100%}.mw-parser-output .ambox .mbox-image{border:none;padding:2px 0 2px 0.5em;text-align:center}.mw-parser-output .ambox .mbox-imageright{border:none;padding:2px 0.5em 2px 0;text-align:center}.mw-parser-output .ambox .mbox-empty-cell{border:none;padding:0;width:1px}.mw-parser-output .ambox .mbox-image-div{width:52px}@media(min-width:720px){.mw-parser-output .ambox{margin:0 10%}}@media print{body.ns-0 .mw-parser-output .ambox{display:none!important}}</style><table class="box-More_citations_needed plainlinks metadata ambox ambox-content ambox-Refimprove" role="presentation"><tbody><tr><td class="mbox-image"><div class="mbox-image-div"><span typeof="mw:File"><a href="/wiki/File:Question_book-new.svg" class="mw-file-description"><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/9/99/Question_book-new.svg/50px-Question_book-new.svg.png" decoding="async" width="50" height="39" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/9/99/Question_book-new.svg/75px-Question_book-new.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/9/99/Question_book-new.svg/100px-Question_book-new.svg.png 2x" data-file-width="512" data-file-height="399" /></a></span></div></td><td class="mbox-text"><div class="mbox-text-span">This article <b>needs additional citations for <a href="/wiki/Wikipedia:Verifiability" title="Wikipedia:Verifiability">verification</a></b>.<span class="hide-when-compact"> Please help <a href="/wiki/Special:EditPage/Stroke_ratio" title="Special:EditPage/Stroke ratio">improve this article</a> by <a href="/wiki/Help:Referencing_for_beginners" title="Help:Referencing for beginners">adding citations to reliable sources</a>. Unsourced material may be challenged and removed.<br /><small><span class="plainlinks"><i>Find sources:</i> <a rel="nofollow" class="external text" href="https://www.google.com/search?as_eq=wikipedia&q=%22Stroke+ratio%22">"Stroke ratio"</a> – <a rel="nofollow" class="external text" href="https://www.google.com/search?tbm=nws&q=%22Stroke+ratio%22+-wikipedia&tbs=ar:1">news</a> <b>·</b> <a rel="nofollow" class="external text" href="https://www.google.com/search?&q=%22Stroke+ratio%22&tbs=bkt:s&tbm=bks">newspapers</a> <b>·</b> <a rel="nofollow" class="external text" href="https://www.google.com/search?tbs=bks:1&q=%22Stroke+ratio%22+-wikipedia">books</a> <b>·</b> <a rel="nofollow" class="external text" href="https://scholar.google.com/scholar?q=%22Stroke+ratio%22">scholar</a> <b>·</b> <a rel="nofollow" class="external text" href="https://www.jstor.org/action/doBasicSearch?Query=%22Stroke+ratio%22&acc=on&wc=on">JSTOR</a></span></small></span> <span class="date-container"><i>(<span class="date">August 2009</span>)</i></span><span class="hide-when-compact"><i> (<small><a href="/wiki/Help:Maintenance_template_removal" title="Help:Maintenance template removal">Learn how and when to remove this message</a></small>)</i></span></div></td></tr></tbody></table> <p class="mw-empty-elt"> </p> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:Bore_Stroke_Ratio_Animation.gif" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/b/bf/Bore_Stroke_Ratio_Animation.gif/220px-Bore_Stroke_Ratio_Animation.gif" decoding="async" width="220" height="268" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/b/bf/Bore_Stroke_Ratio_Animation.gif/330px-Bore_Stroke_Ratio_Animation.gif 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/b/bf/Bore_Stroke_Ratio_Animation.gif/440px-Bore_Stroke_Ratio_Animation.gif 2x" data-file-width="497" data-file-height="606" /></a><figcaption>Bore/Stroke comparison</figcaption></figure> <p><b>Stroke ratio</b>, today universally defined as <b>bore/stroke ratio</b>, is a term to describe the ratio between <a href="/wiki/Bore_(engine)" title="Bore (engine)">cylinder bore</a> diameter and <a href="/wiki/Piston" title="Piston">piston</a> <a href="/wiki/Stroke_(engine)" title="Stroke (engine)">stroke</a> length in a <a href="/wiki/Reciprocating_engine" title="Reciprocating engine">reciprocating piston engine</a>. This can be used for either an <a href="/wiki/Internal_combustion_engine" title="Internal combustion engine">internal combustion engine</a>, where the fuel is burned within the cylinders of the engine, or <a href="/wiki/External_combustion_engine" title="External combustion engine">external combustion engine</a>, such as a <a href="/wiki/Steam_engine" title="Steam engine">steam engine</a>, where the combustion of the fuel takes place <i>outside</i> the working cylinders of the engine. </p> <meta property="mw:PageProp/toc" /> <div class="mw-heading mw-heading2"><h2 id="Conventions">Conventions</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Stroke_ratio&action=edit&section=1" title="Edit section: Conventions"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>The contemporary convention for describing the <i>stroke ratio</i> of a <a href="/wiki/Piston_engine" class="mw-redirect" title="Piston engine">piston engine</a>‘s <a href="/wiki/Cylinder_(engine)" title="Cylinder (engine)">cylinders</a> is its <i>bore/stroke</i> ratio.<sup id="cite_ref-1" class="reference"><a href="#cite_note-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup> </p><p><i>Stroke/bore</i> ratio is an obsolete expression dating to the early era of reciprocating engine development.<sup id="cite_ref-2" class="reference"><a href="#cite_note-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading3"><h3 id="Bore/stroke_ratio"><span id="Bore.2Fstroke_ratio"></span>Bore/stroke ratio</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Stroke_ratio&action=edit&section=2" title="Edit section: Bore/stroke ratio"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>The diameter of the <a href="/wiki/Bore_(engine)" title="Bore (engine)">cylinder bore</a> is divided by the length of the <a href="/wiki/Piston" title="Piston">piston</a> <a href="/wiki/Stroke_(engine)" title="Stroke (engine)">stroke</a> to give the ratio. </p> <div class="mw-heading mw-heading2"><h2 id="Square,_oversquare_and_undersquare_engines"><span id="Square.2C_oversquare_and_undersquare_engines"></span>Square, oversquare and undersquare engines</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Stroke_ratio&action=edit&section=3" title="Edit section: Square, oversquare and undersquare engines"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>The following terms describe the naming conventions for the configurations of the various bore/stroke ratio: </p> <div class="mw-heading mw-heading3"><h3 id="Square">Square<span class="anchor" id="Square_engine"></span></h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Stroke_ratio&action=edit&section=4" title="Edit section: Square"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>A <b>square engine</b> has equal bore <i>and</i> stroke dimensions, giving a bore/stroke value of exactly 1:1. </p> <div class="mw-heading mw-heading4"><h4 id="Square_engine_examples">Square engine examples</h4><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Stroke_ratio&action=edit&section=5" title="Edit section: Square engine examples"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1251242444"><table class="box-Example_farm plainlinks metadata ambox ambox-content" role="presentation"><tbody><tr><td class="mbox-image"><div class="mbox-image-div"><span typeof="mw:File"><span><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/b/b4/Ambox_important.svg/40px-Ambox_important.svg.png" decoding="async" width="40" height="40" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/b/b4/Ambox_important.svg/60px-Ambox_important.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/b/b4/Ambox_important.svg/80px-Ambox_important.svg.png 2x" data-file-width="40" data-file-height="40" /></span></span></div></td><td class="mbox-text"><div class="mbox-text-span">This this section has too many examples. Notability of some exemplars needs to be established, and the list trimmed down substantially of its chaff. <b>may contain <a href="/wiki/Wikipedia:Manual_of_Style/Lists#List_size" title="Wikipedia:Manual of Style/Lists">excessive</a> or <a href="/wiki/Wikipedia:Neutral_point_of_view#Due_and_undue_weight" title="Wikipedia:Neutral point of view">irrelevant</a> examples</b>.<span class="hide-when-compact"> Please help <a class="external text" href="https://en.wikipedia.org/w/index.php?title=Stroke_ratio&action=edit">improve the article</a> by adding descriptive text and removing <a href="/wiki/Wikipedia:Example_cruft" title="Wikipedia:Example cruft">less pertinent examples</a>.</span> <span class="date-container"><i>(<span class="date">November 2023</span>)</i></span></div></td></tr></tbody></table> <p>1953 – <a href="/wiki/Ferrari_250#250_Europa" title="Ferrari 250">Ferrari 250 Europa</a> had <a href="/wiki/Ferrari_Lampredi_engine#V12" title="Ferrari Lampredi engine">Lampredi V12</a> with 68.0 mm × 68.0 mm (2.7 in × 2.7 in) bore and stroke. </p><p>1967 – FIAT 125, 124Sport engine 125A000, 125B000, 125BC000, 1608 ccm, DOHC, 80.0 mm × 80.0 mm (3.15 in × 3.15 in) bore and stroke. </p><p>1970 – Ford <a href="/wiki/Ford_335_engine#400" title="Ford 335 engine">400</a> had a 101.6 mm × 101.6 mm (4.00 in × 4.00 in) bore and stroke. </p><p>1973 – <a href="/wiki/Kawasaki_Z1" title="Kawasaki Z1">Kawasaki Z1</a> and KZ(Z)900 had a 66.0 mm × 66.0 mm (2.60 in × 2.60 in) bore and stroke.<sup id="cite_ref-3" class="reference"><a href="#cite_note-3"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup> </p><p>1982 - <a href="/wiki/Honda_Nighthawk_250" title="Honda Nighthawk 250">Honda Nighthawk 250</a> and <a href="/wiki/Honda_CMX250C" title="Honda CMX250C">Honda CMX250C</a> Rebel have a 53.0 mm × 53.0 mm (2.09 in × 2.09 in) bore and stroke.<sup id="cite_ref-4" class="reference"><a href="#cite_note-4"><span class="cite-bracket">[</span>4<span class="cite-bracket">]</span></a></sup> </p><p>1983 – <a href="/wiki/Mazda" title="Mazda">Mazda</a> <a href="/wiki/Mazda_F_engine" title="Mazda F engine">FE 2.0L</a> inline four-cylinder engine with a 86.0 mm × 86.0 mm (3.4 in × 3.4 in) bore and stroke. </p><p>1987 – The Opel/Vauxhall 2.0 L <a href="/wiki/C20NE" class="mw-redirect" title="C20NE">GM Family II engines</a> are square at 86.0 mm × 86.0 mm (3.39 in × 3.39 in) bore and stroke; example as C20XE C20NE C20LET X20A X20XEV X20XER Z20LET Z20LEH Z20LER A20NHT A20NFT. </p><p>1989 – <a href="/wiki/Nissan_Motors" class="mw-redirect" title="Nissan Motors">Nissan's</a> <a href="/wiki/Nissan_SR_engine#SR20DE_and_SR20De" title="Nissan SR engine">SR20DE</a> is a square engine, with an 86.0 mm × 86.0 mm (3.39 in × 3.39 in) bore and stroke. </p><p>1990–2010 <a href="/wiki/Saab_Automobile" title="Saab Automobile">Saab B234/B235</a> is a square engine, with a 90.0 mm × 90.0 mm (3.54 in × 3.54 in) bore and stroke. </p><p>1991 – <a href="/wiki/Ford_Modular_engine#4.6_L" title="Ford Modular engine">Ford's 4.6</a> V8 OHC engine has a 90.2 mm × 90.0 mm (3.552 in × 3.543 in) bore and stroke. </p><p>1995 – The <a href="/wiki/BMW" title="BMW">BMW</a> <a href="/wiki/BMW_M52" title="BMW M52">M52</a> engine with a displacement of 2793 cubic centimeters is an example of a perfect square engine with an 84.0 mm × 84.0 mm (3.31 in × 3.31 in) bore and stroke. </p><p>1996 – Jaguar's <a href="/wiki/Jaguar_AJ-V8_engine#4.0_L" title="Jaguar AJ-V8 engine">AJ-V8</a> engine in 4.0-litre form has an 86.0 mm bore and stroke. </p><p>2000 – <a href="/wiki/Mercedes-Benz" title="Mercedes-Benz">Mercedes-Benz</a> 4.0-litre (3996 cc; 243.9 cu in) <a href="/wiki/Mercedes-Benz_OM628_engine" title="Mercedes-Benz OM628 engine">OM628</a> V8 diesel engine is an example of a square engine – with an 86.0 mm × 86.0 mm (3.39 in × 3.39 in) bore and stroke. </p> <div class="mw-heading mw-heading3"><h3 id="Oversquare">Oversquare<span class="anchor" id="Oversquare_or_short-stroke_engine"></span></h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Stroke_ratio&action=edit&section=6" title="Edit section: Oversquare"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>An engine is described as <b>oversquare</b> or <b>short-stroke</b> if its cylinders have a greater bore diameter than its stroke length, giving a bore/stroke ratio greater than 1:1. </p><p>An oversquare engine allows for more and larger valves in the head of the cylinder, higher possible rpm by lowering maximum piston speed, and lower crank stress due to the lower peak piston acceleration for the same engine (rotational) speed. Because these characteristics favor higher engine speeds, oversquare engines are often tuned to develop peak torque at a relatively high speed. </p><p>Due to the increased piston and head surface area, the heat loss increases as the bore/stroke ratio is increased. Thus an excessively high ratio can lead to a decreased <a href="/wiki/Thermal_efficiency" title="Thermal efficiency">thermal efficiency</a> compared to other engine geometries. The large size/width of the combustion chamber at ignition can cause increased inhomogeneity in the air/fuel mixture during combustion, resulting in higher emissions. </p><p>The reduced stroke length allows for a shorter cylinder and sometimes a shorter connecting rod, generally making oversquare engines less tall but wider than undersquare engines of similar <a href="/wiki/Engine_displacement" title="Engine displacement">engine displacement</a>. </p> <div class="mw-heading mw-heading4"><h4 id="Oversquare_engine_examples">Oversquare engine examples</h4><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Stroke_ratio&action=edit&section=7" title="Edit section: Oversquare engine examples"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Oversquare engines (a.k.a. "short stroke engines") are very common, as they allow higher <a href="/wiki/Revolutions_per_minute" title="Revolutions per minute">rpm</a> (and thus more power), without excessive piston speed. </p><p>Examples include both Chevrolet and Ford small-block V8s; the <a href="/wiki/GMC_V6_engine#478" title="GMC V6 engine">GMC 478</a> V6 has a bore/stroke ratio of 1.33. The 1.6 litre version of the <a href="/wiki/BMW_N45" title="BMW N45">BMW N45</a> gasoline engine has a bore/stroke ratio of 1.167. </p><p><a href="/wiki/Flat_engine" title="Flat engine">Horizontally opposed, also known as "Boxer" or "flat", engines</a> typically feature oversquare designs since any increase in stroke length would result in twice the increase in overall engine width. This is particularly so in <a href="/wiki/Subaru" title="Subaru">Subaru</a>’s front-engine layout, where the steering angle of the front wheels is constrained by the width of the engine. The <a href="/wiki/Subaru_EJ_engine" title="Subaru EJ engine">Subaru EJ181 engine</a> develops peak torque at speeds as low as 3200 rpm. </p><p>Nissan's RB, VQ, VK, VH and VR38DETT engines are all oversquare. Additionally, <a href="/wiki/Nissan_SR_engine#SR16VE" title="Nissan SR engine">SR16VE</a> engine found in <a href="/wiki/Nissan_Pulsar" title="Nissan Pulsar">Nissan Pulsar</a> VZ-R and VZ-R N1 is an oversquare engine with 86 millimetres (3.39 in) bore and 68.7 millimetres (2.70 in) stroke, giving it 175–200 horsepower (130–150 kW) but relatively small torque of 119–134 pound-feet (161–182 N⋅m; 16.5–18.5 kg⋅m) </p><p>Extreme oversquare engines are found in <a href="/wiki/Formula_One" title="Formula One">Formula One</a> racing cars, where strict rules limit displacement, thereby necessitating that power be achieved through high engine speeds. Stroke ratios approaching 2.5:1 are allowed,<sup id="cite_ref-5" class="reference"><a href="#cite_note-5"><span class="cite-bracket">[</span>a<span class="cite-bracket">]</span></a></sup> enabling engine speeds of 18,000 rpm while remaining reliable for multiple races.<sup id="cite_ref-6" class="reference"><a href="#cite_note-6"><span class="cite-bracket">[</span>5<span class="cite-bracket">]</span></a></sup> </p><p>The <a href="/wiki/Ducati_1199" title="Ducati 1199">Ducati Panigale</a> <a href="/wiki/Motorcycle_engine" title="Motorcycle engine">motorcycle engine</a> is extremely oversquare with a bore/stroke ratio of 1.84:1. It was given the name "SuperQuadro" by <a href="/wiki/Ducati" title="Ducati">Ducati</a>, roughly translated as "super-square" from Italian.<sup id="cite_ref-7" class="reference"><a href="#cite_note-7"><span class="cite-bracket">[</span>6<span class="cite-bracket">]</span></a></sup> </p><p>The <a href="/wiki/Side-valve" class="mw-redirect" title="Side-valve">side-valve</a> Belgian <a href="/wiki/D-Motor_LF26" title="D-Motor LF26">D-Motor LF26</a> <a href="/wiki/Aircraft_engine" title="Aircraft engine">aero-engine</a> has a bore/stroke ratio of 1.4:1.<sup id="cite_ref-8" class="reference"><a href="#cite_note-8"><span class="cite-bracket">[</span>7<span class="cite-bracket">]</span></a></sup> </p><p>Early <a href="/wiki/Mercedes-Benz_M116_engine" title="Mercedes-Benz M116 engine">Mercedes-Benz M116 engines</a> had a 92 millimetres (3.62 in) bore and a 65.6 millimetres (2.58 in) stroke for a 3.5 litre V8.<sup id="cite_ref-9" class="reference"><a href="#cite_note-9"><span class="cite-bracket">[</span>8<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading3"><h3 id="Undersquare">Undersquare<span class="anchor" id="Undersquare_or_long-stroke_engine"></span><span class="anchor" id="undersquare"></span></h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Stroke_ratio&action=edit&section=8" title="Edit section: Undersquare"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>An engine is described as <b>undersquare</b> or <b>long-stroke</b> if its cylinders have a smaller bore (width, diameter) than its stroke (length of piston travel) - giving a ratio value of less than 1:1. </p><p>At a given engine speed, a longer stroke increases engine friction and increases stress on the crankshaft due to the higher peak piston acceleration. The smaller bore also reduces the area available for valves in the cylinder head, requiring them to be smaller or fewer in number. </p><p>Undersquare engines often exhibit peak torque at lower rpm than an oversquare engine due to their smaller valves and high piston speed limiting their potential to rev higher. </p><p><span class="clarify-content" style="padding-left:0.1em; padding-right:0.1em; color:var(--color-subtle, #54595d); border:1px solid var(--border-color-subtle, #c8ccd1);">Undersquare engines have become more common lately, as manufacturers push for more and more efficient engines and higher fuel economy.</span><sup class="noprint Inline-Template Template-Clarify" style="margin-left:0.1em; white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Please_clarify" title="Wikipedia:Please clarify"><span title="How does an undersquare engine create more efficiency and higher fuel economy? Only the claim is advanced. (November 2023)">clarify</span></a></i>]</sup><sup id="cite_ref-10" class="reference"><a href="#cite_note-10"><span class="cite-bracket">[</span>9<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading4"><h4 id="Undersquare_engine_examples">Undersquare engine examples</h4><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Stroke_ratio&action=edit&section=9" title="Edit section: Undersquare engine examples"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Many inline engines, particularly those mounted transversely in front-wheel-drive cars, utilize an undersquare design. The smaller bore allows for a shorter engine that increases room available for the front wheels to steer. Examples of this include many <a href="/wiki/List_of_Volkswagen_Group_petrol_engines" title="List of Volkswagen Group petrol engines">Volkswagen</a>, <a href="/wiki/List_of_Nissan_engines" title="List of Nissan engines">Nissan</a>, <a href="/wiki/List_of_Honda_engines" title="List of Honda engines">Honda</a>, and <a href="/wiki/List_of_Mazda_engines" title="List of Mazda engines">Mazda</a> engines. The <a href="/wiki/Toyota_KR_engine#1KR-FE" title="Toyota KR engine">1KR-FE</a>-engine used in the <a href="/wiki/Toyota_Aygo" title="Toyota Aygo">Toyota Aygo</a>, <a href="/wiki/Citro%C3%ABn_C1" title="Citroën C1">Citroën C1</a> and <a href="/wiki/Peugeot_107" title="Peugeot 107">Peugeot 107</a> amongst others is an example of a modern long-stroke engine widely used in <a href="/wiki/FF_layout" class="mw-redirect" title="FF layout">FF layout</a> cars. This engine has a bore and stroke of 71 mm × 84 mm (2.8 in × 3.3 in) stroke giving it a bore/stroke ratio of 0.845:1. Some rear-wheel-drive cars that borrow engines from front-wheel-drive cars (such as the <a href="/wiki/Mazda_MX-5" title="Mazda MX-5">Mazda MX-5</a>) use an undersquare design. </p><p>BMW's acclaimed <a href="/wiki/BMW_M54#S54B32" title="BMW M54">S54B32</a> M54 engine was undersquare with a bore and stroke of 87 mm × 91 mm (3.4 in × 3.6 in)), offering a world record torque-per-litre figure (114 N⋅m/L, 1.38 lb⋅ft/cu in) for normally-aspirated production engines at the time; this record stood until Ferrari unveiled the <a href="/wiki/458_Italia" class="mw-redirect" title="458 Italia">458 Italia</a>. </p><p>Many <a href="/wiki/United_Kingdom" title="United Kingdom">British</a> automobile companies used undersquare designs until the 1950s, largely because of a motor tax system that <a href="/wiki/RAC_horsepower" class="mw-redirect" title="RAC horsepower">taxed cars by their cylinder bore</a>. This includes the <a href="/wiki/BMC_A-Series_engine" class="mw-redirect" title="BMC A-Series engine">BMC A-Series engine</a>, and many <a href="/wiki/Nissan" title="Nissan">Nissan</a> derivatives. The <a href="/wiki/Trojan_(automobile)" title="Trojan (automobile)">Trojan Car</a> used an undersquare, <a href="/wiki/Split-single" class="mw-redirect" title="Split-single">split piston</a>, <a href="/wiki/Two_stroke" class="mw-redirect" title="Two stroke">two stroke</a>, two-cylinder inline engine; this was partly for this tax advantage and partly because its proportions allowed flexing V-shaped connecting rods for the two pistons of each U-shaped cylinder, which was cheaper and simpler than two connecting rods joined with an additional bearing. </p><p>Their French and German competitors at the time also used undersquare designs even in absence of the tax reasoning, e. g. <a href="/wiki/Renault_Billancourt_engine" title="Renault Billancourt engine">Renault Billancourt engine</a> and <a href="/wiki/Opel_straight-6_engine" title="Opel straight-6 engine">Opel straight-6 engine</a>. </p><p>The 225 cu in (3.7 <a href="/wiki/Litre" title="Litre">litre</a>) <a href="/wiki/Chrysler_Slant-6_engine" title="Chrysler Slant-6 engine">Chrysler Slant-6 engine</a> is undersquare, with a bore and stroke of 86 mm × 105 mm (3.4 in × 4.1 in) stroke (bore/stroke ratio = 0.819:1). </p><p>The Ford <a href="/wiki/Ford_Modular_engine#5.4.C2.A0L" title="Ford Modular engine">5.4L Modular Engine</a> features a bore and stroke of 90.1 mm × 105.8 mm (3.55 in × 4.17 in), which makes a bore/stroke ratio of 0.852:1. Since the stroke is significantly longer than the bore, the SOHC 16V (2-valve per cylinder) version of this engine is able to generate a peak torque of 350 lb·ft as low as 2501 rpm. </p><p>The Willys Jeep <a href="/wiki/Willys_Go_Devil_engine" title="Willys Go Devil engine">L134</a> and <a href="/wiki/Willys_Hurricane_engine" title="Willys Hurricane engine">F134</a> engines were undersquare, with a bore and stroke of 79.4 mm × 111.1 mm (3.13 in × 4.37 in) stroke (bore/stroke ratio = 0.714:1). </p><p>The <a href="/wiki/Dodge_Power_Wagon" title="Dodge Power Wagon">Dodge Power Wagon</a> used a <a href="/wiki/Straight-six_engine" title="Straight-six engine">straight-six</a> <a href="/wiki/Chrysler_Flathead_engine" class="mw-redirect" title="Chrysler Flathead engine">Chrysler Flathead engine</a> of 230 cu in (3.8 L) with a bore and stroke of 83 mm × 117 mm (3.3 in × 4.6 in), yielding a substantially undersquare bore/stroke ratio of 0.709:1. </p><p>The 4-litre <a href="/wiki/Ford_Barra_engine#Straight-six_engine" title="Ford Barra engine">Barra Inline 6</a> and <a href="/wiki/Ford_straight-six_engine#OHC_and_Intech" title="Ford straight-six engine">Intech</a> engines from the Australian <a href="/wiki/Ford_Falcon_(Australia)" title="Ford Falcon (Australia)">Ford Falcon</a>, uses a bore and stroke of 92.21 mm × 99.31 mm (3.63 in × 3.91 in) stroke, which equates to a 0.929:1 bore-stroke ratio. </p><p>The 292 Chevrolet I6 is also undersquare, with a bore and stroke of 98.4 mm × 104.8 mm (3.875 in × 4.125 in) in (bore/stroke ratio = 0.939:1). </p><p>Mitsubishi's 4G63T engine found primarily in many generations of <a href="/wiki/Mitsubishi_Lancer_Evolution" title="Mitsubishi Lancer Evolution">Mitsubishi Lancer Evolution</a> is an undersquare engine with a bore and stroke of 85 mm × 88 mm (3.3 in × 3.5 in). </p><p>The <a href="/wiki/Jaguar_XK6_engine" class="mw-redirect" title="Jaguar XK6 engine">Jaguar XK6 engine</a>, used in all 6-cylinder Jaguars from 1949 to 1987 was undersquare. For example, the 4.2 litre engine had a bore and stroke of 92.08 mm × 106 mm (3.63 in × 4.17 in), providing a bore/stroke ratio of 0.869:1. </p><p>Virtually all piston engines used in military aircraft were long-stroke engines. The PW R-2800, Wright R-3350, <a href="/wiki/Pratt_%26_Whitney_R-4360_Wasp_Major" title="Pratt & Whitney R-4360 Wasp Major">Pratt & Whitney R-4360 Wasp Major</a>, Rolls-Royce Merlin (1650), Allison V-1710, and Hispano-Suiza 12Y-Z are only a few of more than a hundred examples. </p><p>All diesel-powered ships have massively undersquare marine engines, usually using <a href="/wiki/Crosshead" title="Crosshead">crossheads</a>. A <a href="/wiki/W%C3%A4rtsil%C3%A4" title="Wärtsilä">Wärtsilä</a> <a href="/wiki/W%C3%A4rtsil%C3%A4-Sulzer_RT-flex96-C" class="mw-redirect" title="Wärtsilä-Sulzer RT-flex96-C">two-stroke marine diesel engine</a> has a bore and stroke of 960 mm × 2,500 mm (37.8 in × 98.4 in), (bore/stroke ratio = 0.384:1). </p><p>While most modern <a href="/wiki/Motorcycle_engine" title="Motorcycle engine">motorcycle engines</a> are square or oversquare, some are undersquare. The <a href="/wiki/Kawasaki_Z1300" title="Kawasaki Z1300">Kawasaki Z1300</a>'s <a href="/wiki/Straight-six_engine" title="Straight-six engine">straight-six engine</a> was made undersquare to minimise engine width, more recently, a new <a href="/wiki/Straight-twin_engine" title="Straight-twin engine">straight-twin engine</a> for the <a href="/wiki/Honda_NC700_series" title="Honda NC700 series">Honda NC700 series</a> used an undersquare design to achieve better <a href="/wiki/Combustion_efficiency" title="Combustion efficiency">combustion efficiency</a> in order to reduce fuel consumption.<sup id="cite_ref-11" class="reference"><a href="#cite_note-11"><span class="cite-bracket">[</span>10<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-12" class="reference"><a href="#cite_note-12"><span class="cite-bracket">[</span>11<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading2"><h2 id="Notes">Notes</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Stroke_ratio&action=edit&section=10" title="Edit section: Notes"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <style data-mw-deduplicate="TemplateStyles:r1239543626">.mw-parser-output .reflist{margin-bottom:0.5em;list-style-type:decimal}@media screen{.mw-parser-output .reflist{font-size:90%}}.mw-parser-output .reflist .references{font-size:100%;margin-bottom:0;list-style-type:inherit}.mw-parser-output .reflist-columns-2{column-width:30em}.mw-parser-output .reflist-columns-3{column-width:25em}.mw-parser-output .reflist-columns{margin-top:0.3em}.mw-parser-output .reflist-columns ol{margin-top:0}.mw-parser-output .reflist-columns li{page-break-inside:avoid;break-inside:avoid-column}.mw-parser-output .reflist-upper-alpha{list-style-type:upper-alpha}.mw-parser-output .reflist-upper-roman{list-style-type:upper-roman}.mw-parser-output .reflist-lower-alpha{list-style-type:lower-alpha}.mw-parser-output .reflist-lower-greek{list-style-type:lower-greek}.mw-parser-output .reflist-lower-roman{list-style-type:lower-roman}</style><div class="reflist reflist-lower-alpha"> <div class="mw-references-wrap"><ol class="references"> <li id="cite_note-5"><span class="mw-cite-backlink"><b><a href="#cite_ref-5">^</a></b></span> <span class="reference-text">There is no actual restriction on bore:stroke ratio, but cylinder bores are limited to 98 millimetres or 3.86 inches and capacity to 2,400 cubic centimetres (150 cu in).</span> </li> </ol></div></div> <div class="mw-heading mw-heading2"><h2 id="References">References</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Stroke_ratio&action=edit&section=11" title="Edit section: References"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1239543626"><div class="reflist"> <div class="mw-references-wrap mw-references-columns"><ol class="references"> <li id="cite_note-1"><span class="mw-cite-backlink"><b><a href="#cite_ref-1">^</a></b></span> <span class="reference-text"> <b>Bore/stroke</b> is the more commonly used term, with usage in <a href="/wiki/North_America" title="North America">North America</a>, <a href="/wiki/Europe" title="Europe">Europe</a>, <a href="/wiki/United_Kingdom" title="United Kingdom">United Kingdom</a>, <a href="/wiki/Asia" title="Asia">Asia</a>, and <a href="/wiki/Australia" title="Australia">Australia</a>.<sup class="noprint Inline-Template Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources. (November 2023)">citation needed</span></a></i>]</sup></span> </li> <li id="cite_note-2"><span class="mw-cite-backlink"><b><a href="#cite_ref-2">^</a></b></span> <span class="reference-text"><style data-mw-deduplicate="TemplateStyles:r1238218222">.mw-parser-output cite.citation{font-style:inherit;word-wrap:break-word}.mw-parser-output .citation q{quotes:"\"""\"""'""'"}.mw-parser-output .citation:target{background-color:rgba(0,127,255,0.133)}.mw-parser-output .id-lock-free.id-lock-free a{background:url("//upload.wikimedia.org/wikipedia/commons/6/65/Lock-green.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-limited.id-lock-limited a,.mw-parser-output .id-lock-registration.id-lock-registration a{background:url("//upload.wikimedia.org/wikipedia/commons/d/d6/Lock-gray-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-subscription.id-lock-subscription a{background:url("//upload.wikimedia.org/wikipedia/commons/a/aa/Lock-red-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .cs1-ws-icon a{background:url("//upload.wikimedia.org/wikipedia/commons/4/4c/Wikisource-logo.svg")right 0.1em center/12px no-repeat}body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-free a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-limited a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-registration a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-subscription a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .cs1-ws-icon a{background-size:contain;padding:0 1em 0 0}.mw-parser-output .cs1-code{color:inherit;background:inherit;border:none;padding:inherit}.mw-parser-output .cs1-hidden-error{display:none;color:var(--color-error,#d33)}.mw-parser-output .cs1-visible-error{color:var(--color-error,#d33)}.mw-parser-output .cs1-maint{display:none;color:#085;margin-left:0.3em}.mw-parser-output .cs1-kern-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right{padding-right:0.2em}.mw-parser-output .citation .mw-selflink{font-weight:inherit}@media screen{.mw-parser-output .cs1-format{font-size:95%}html.skin-theme-clientpref-night .mw-parser-output .cs1-maint{color:#18911f}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .cs1-maint{color:#18911f}}</style><cite id="WA-37-Stroke" class="citation journal cs1">Ingram, Edward (April 1916). <a rel="nofollow" class="external text" href="https://books.google.com/books?id=EVTmAAAAMAAJ&pg=PA275">"As to the Matter of Stroke"</a>. <i>Horseless Age</i>. <b>37</b> (6 & 7): 275, 325<span class="reference-accessdate">. Retrieved <span class="nowrap">12 November</span> 2015</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Horseless+Age&rft.atitle=As+to+the+Matter+of+Stroke&rft.volume=37&rft.issue=6+%26+7&rft.pages=275%2C+325&rft.date=1916-04&rft.aulast=Ingram&rft.aufirst=Edward&rft_id=https%3A%2F%2Fbooks.google.com%2Fbooks%3Fid%3DEVTmAAAAMAAJ%26pg%3DPA275&rfr_id=info%3Asid%2Fen.wikipedia.org%3AStroke+ratio" class="Z3988"></span></span> </li> <li id="cite_note-3"><span class="mw-cite-backlink"><b><a href="#cite_ref-3">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="http://www.jsae.or.jp/autotech/data_e/4-18e.html">"Kawasaki 900 Super Four"</a>. <i>240 Landmarks of Japanese Automotive Technology</i>. Society of Automotive Engineers of Japan, Inc<span class="reference-accessdate">. Retrieved <span class="nowrap">6 November</span> 2013</span>. <q>Journalists and riders called it the king of motorcycles, and it gained a reputation as a super sport model all over the world. The Super Four boasted high performance and quality. This best-selling motorcycle won many prizes around the world within only six months of its release.</q></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=240+Landmarks+of+Japanese+Automotive+Technology&rft.atitle=Kawasaki+900+Super+Four&rft_id=http%3A%2F%2Fwww.jsae.or.jp%2Fautotech%2Fdata_e%2F4-18e.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3AStroke+ratio" class="Z3988"></span></span> </li> <li id="cite_note-4"><span class="mw-cite-backlink"><b><a href="#cite_ref-4">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="http://www.hondanews.com/channels/powersports-motorcycles-custom-rebel/releases/2013-honda-rebel-specifications">"2013 Honda Rebel Specifications"</a>. <i>Honda Media Newsroom</i>. American Honda Motor Co. 4 September 2012<span class="reference-accessdate">. Retrieved <span class="nowrap">25 March</span> 2014</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=Honda+Media+Newsroom&rft.atitle=2013+Honda+Rebel+Specifications&rft.date=2012-09-04&rft_id=http%3A%2F%2Fwww.hondanews.com%2Fchannels%2Fpowersports-motorcycles-custom-rebel%2Freleases%2F2013-honda-rebel-specifications&rfr_id=info%3Asid%2Fen.wikipedia.org%3AStroke+ratio" class="Z3988"></span></span> </li> <li id="cite_note-6"><span class="mw-cite-backlink"><b><a href="#cite_ref-6">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="http://argent.fia.com/web/fia-public.nsf/2B2B158DE64879C7C12578C0004B1DF6/$FILE/2011_F1__TECHNICAL_REGULATIONS_30-06-2011.pdf">"2011F1 Technical Regulations"</a> <span class="cs1-format">(PDF)</span>. FIA<span class="reference-accessdate">. Retrieved <span class="nowrap">21 July</span> 2011</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=2011F1+Technical+Regulations&rft.pub=FIA&rft_id=http%3A%2F%2Fargent.fia.com%2Fweb%2Ffia-public.nsf%2F2B2B158DE64879C7C12578C0004B1DF6%2F%24FILE%2F2011_F1__TECHNICAL_REGULATIONS_30-06-2011.pdf&rfr_id=info%3Asid%2Fen.wikipedia.org%3AStroke+ratio" class="Z3988"></span></span> </li> <li id="cite_note-7"><span class="mw-cite-backlink"><b><a href="#cite_ref-7">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="http://www.1199panigale.ducati.com/en/#">"Ducati 1199 Panigale - Ducati"</a>. <i>www.1199panigale.ducati.com</i><span class="reference-accessdate">. Retrieved <span class="nowrap">9 April</span> 2018</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=www.1199panigale.ducati.com&rft.atitle=Ducati+1199+Panigale+-+Ducati&rft_id=http%3A%2F%2Fwww.1199panigale.ducati.com%2Fen%2F%23&rfr_id=info%3Asid%2Fen.wikipedia.org%3AStroke+ratio" class="Z3988"></span></span> </li> <li id="cite_note-8"><span class="mw-cite-backlink"><b><a href="#cite_ref-8">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20120425032911/http://d-motor1.vpweb.be/Price---product-specifications.html">"Price"</a>. Netherlands: D-Motor. Archived from <a rel="nofollow" class="external text" href="http://d-motor1.vpweb.be/Price---product-specifications.html">the original</a> on 25 April 2012.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Price&rft.place=Netherlands&rft.pub=D-Motor&rft_id=http%3A%2F%2Fd-motor1.vpweb.be%2FPrice---product-specifications.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3AStroke+ratio" class="Z3988"></span></span> </li> <li id="cite_note-9"><span class="mw-cite-backlink"><b><a href="#cite_ref-9">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20070831111734/http://www.uniquecarsandparts.com.au/mercedes_350SL_technical_specifications.htm">"Mercedes Benz 350SL Technical Specifications"</a>. Archived from <a rel="nofollow" class="external text" href="http://www.uniquecarsandparts.com.au/mercedes_350SL_technical_specifications.htm">the original</a> on 31 August 2007.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Mercedes+Benz+350SL+Technical+Specifications&rft_id=http%3A%2F%2Fwww.uniquecarsandparts.com.au%2Fmercedes_350SL_technical_specifications.htm&rfr_id=info%3Asid%2Fen.wikipedia.org%3AStroke+ratio" class="Z3988"></span></span> </li> <li id="cite_note-10"><span class="mw-cite-backlink"><b><a href="#cite_ref-10">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation pressrelease cs1"><a rel="nofollow" class="external text" href="https://newsroom.toyota.co.jp/en/powertrain2018/engine/">"2.0-liter Dynamic Force Engine, a New 2.0-liter Direct-injection, Inline 4-cylinder Gasoline Engine"</a> (Press release). Japan: Toyota. 26 February 2018<span class="reference-accessdate">. Retrieved <span class="nowrap">11 June</span> 2018</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=2.0-liter+Dynamic+Force+Engine%2C+a+New+2.0-liter+Direct-injection%2C+Inline+4-cylinder+Gasoline+Engine&rft.place=Japan&rft.pub=Toyota&rft.date=2018-02-26&rft_id=https%3A%2F%2Fnewsroom.toyota.co.jp%2Fen%2Fpowertrain2018%2Fengine%2F&rfr_id=info%3Asid%2Fen.wikipedia.org%3AStroke+ratio" class="Z3988"></span></span> </li> <li id="cite_note-11"><span class="mw-cite-backlink"><b><a href="#cite_ref-11">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="http://world.honda.com/Global-700cc-engine/Tech-details/page05.html">"Global 700cc Engine for Next-Generation : Technical details"</a>. <i>Honda Worldwide</i>. Honda Motor Co. 8 March 2012. p. 5<span class="reference-accessdate">. Retrieved <span class="nowrap">25 March</span> 2014</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=Honda+Worldwide&rft.atitle=Global+700cc+Engine+for+Next-Generation+%3A+Technical+details&rft.pages=5&rft.date=2012-03-08&rft_id=http%3A%2F%2Fworld.honda.com%2FGlobal-700cc-engine%2FTech-details%2Fpage05.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3AStroke+ratio" class="Z3988"></span></span> </li> <li id="cite_note-12"><span class="mw-cite-backlink"><b><a href="#cite_ref-12">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFGarrett2012" class="citation news cs1">Garrett, Jerry (14 September 2012). <a rel="nofollow" class="external text" href="https://www.nytimes.com/2012/09/16/automobiles/autoreviews/reality-check-from-honda-in-touch-with-economics.html">"Reality Check From Honda, in Touch With Economics"</a>. <i>New York Times</i><span class="reference-accessdate">. Retrieved <span class="nowrap">25 March</span> 2014</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=New+York+Times&rft.atitle=Reality+Check+From+Honda%2C+in+Touch+With+Economics&rft.date=2012-09-14&rft.aulast=Garrett&rft.aufirst=Jerry&rft_id=https%3A%2F%2Fwww.nytimes.com%2F2012%2F09%2F16%2Fautomobiles%2Fautoreviews%2Freality-check-from-honda-in-touch-with-economics.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3AStroke+ratio" class="Z3988"></span></span> </li> </ol></div></div> <style data-mw-deduplicate="TemplateStyles:r1235681985">.mw-parser-output .side-box{margin:4px 0;box-sizing:border-box;border:1px solid #aaa;font-size:88%;line-height:1.25em;background-color:var(--background-color-interactive-subtle,#f8f9fa);display:flow-root}.mw-parser-output .side-box-abovebelow,.mw-parser-output .side-box-text{padding:0.25em 0.9em}.mw-parser-output .side-box-image{padding:2px 0 2px 0.9em;text-align:center}.mw-parser-output .side-box-imageright{padding:2px 0.9em 2px 0;text-align:center}@media(min-width:500px){.mw-parser-output .side-box-flex{display:flex;align-items:center}.mw-parser-output .side-box-text{flex:1;min-width:0}}@media(min-width:720px){.mw-parser-output .side-box{width:238px}.mw-parser-output .side-box-right{clear:right;float:right;margin-left:1em}.mw-parser-output .side-box-left{margin-right:1em}}</style><style data-mw-deduplicate="TemplateStyles:r1237033735">@media print{body.ns-0 .mw-parser-output .sistersitebox{display:none!important}}@media screen{html.skin-theme-clientpref-night .mw-parser-output .sistersitebox img[src*="Wiktionary-logo-en-v2.svg"]{background-color:white}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .sistersitebox img[src*="Wiktionary-logo-en-v2.svg"]{background-color:white}}</style><div class="side-box side-box-right plainlinks sistersitebox"><style data-mw-deduplicate="TemplateStyles:r1126788409">.mw-parser-output .plainlist ol,.mw-parser-output .plainlist ul{line-height:inherit;list-style:none;margin:0;padding:0}.mw-parser-output .plainlist ol li,.mw-parser-output .plainlist ul li{margin-bottom:0}</style> <div class="side-box-flex"> <div class="side-box-image"><span class="noviewer" typeof="mw:File"><span><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/30px-Commons-logo.svg.png" decoding="async" width="30" height="40" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/45px-Commons-logo.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/59px-Commons-logo.svg.png 2x" data-file-width="1024" data-file-height="1376" /></span></span></div> <div class="side-box-text plainlist">Wikimedia Commons has media related to <span style="font-weight: bold; font-style: italic;"><a href="https://commons.wikimedia.org/wiki/Category:Internal_combustion_engines" class="extiw" title="commons:Category:Internal combustion engines">Internal combustion engines</a></span>.</div></div> </div> <div class="navbox-styles"><style data-mw-deduplicate="TemplateStyles:r1129693374">.mw-parser-output .hlist dl,.mw-parser-output .hlist ol,.mw-parser-output .hlist ul{margin:0;padding:0}.mw-parser-output .hlist dd,.mw-parser-output .hlist dt,.mw-parser-output .hlist li{margin:0;display:inline}.mw-parser-output .hlist.inline,.mw-parser-output .hlist.inline dl,.mw-parser-output .hlist.inline ol,.mw-parser-output .hlist.inline ul,.mw-parser-output .hlist dl dl,.mw-parser-output .hlist dl ol,.mw-parser-output .hlist dl ul,.mw-parser-output .hlist ol dl,.mw-parser-output .hlist ol ol,.mw-parser-output .hlist ol ul,.mw-parser-output .hlist ul dl,.mw-parser-output .hlist ul ol,.mw-parser-output .hlist ul ul{display:inline}.mw-parser-output .hlist .mw-empty-li{display:none}.mw-parser-output .hlist dt::after{content:": "}.mw-parser-output .hlist dd::after,.mw-parser-output .hlist li::after{content:" · ";font-weight:bold}.mw-parser-output .hlist dd:last-child::after,.mw-parser-output .hlist dt:last-child::after,.mw-parser-output .hlist li:last-child::after{content:none}.mw-parser-output .hlist dd dd:first-child::before,.mw-parser-output .hlist dd dt:first-child::before,.mw-parser-output .hlist dd li:first-child::before,.mw-parser-output .hlist dt dd:first-child::before,.mw-parser-output .hlist dt dt:first-child::before,.mw-parser-output .hlist dt li:first-child::before,.mw-parser-output .hlist li dd:first-child::before,.mw-parser-output .hlist li dt:first-child::before,.mw-parser-output .hlist li li:first-child::before{content:" (";font-weight:normal}.mw-parser-output .hlist dd dd:last-child::after,.mw-parser-output .hlist dd dt:last-child::after,.mw-parser-output .hlist dd li:last-child::after,.mw-parser-output .hlist dt dd:last-child::after,.mw-parser-output .hlist dt dt:last-child::after,.mw-parser-output .hlist dt li:last-child::after,.mw-parser-output .hlist li dd:last-child::after,.mw-parser-output .hlist li dt:last-child::after,.mw-parser-output .hlist li li:last-child::after{content:")";font-weight:normal}.mw-parser-output .hlist ol{counter-reset:listitem}.mw-parser-output .hlist ol>li{counter-increment:listitem}.mw-parser-output .hlist ol>li::before{content:" "counter(listitem)"\a0 "}.mw-parser-output .hlist dd ol>li:first-child::before,.mw-parser-output .hlist dt ol>li:first-child::before,.mw-parser-output .hlist li ol>li:first-child::before{content:" ("counter(listitem)"\a0 "}</style><style data-mw-deduplicate="TemplateStyles:r1236075235">.mw-parser-output .navbox{box-sizing:border-box;border:1px solid #a2a9b1;width:100%;clear:both;font-size:88%;text-align:center;padding:1px;margin:1em auto 0}.mw-parser-output .navbox .navbox{margin-top:0}.mw-parser-output .navbox+.navbox,.mw-parser-output .navbox+.navbox-styles+.navbox{margin-top:-1px}.mw-parser-output .navbox-inner,.mw-parser-output .navbox-subgroup{width:100%}.mw-parser-output .navbox-group,.mw-parser-output .navbox-title,.mw-parser-output .navbox-abovebelow{padding:0.25em 1em;line-height:1.5em;text-align:center}.mw-parser-output .navbox-group{white-space:nowrap;text-align:right}.mw-parser-output .navbox,.mw-parser-output .navbox-subgroup{background-color:#fdfdfd}.mw-parser-output .navbox-list{line-height:1.5em;border-color:#fdfdfd}.mw-parser-output .navbox-list-with-group{text-align:left;border-left-width:2px;border-left-style:solid}.mw-parser-output tr+tr>.navbox-abovebelow,.mw-parser-output tr+tr>.navbox-group,.mw-parser-output tr+tr>.navbox-image,.mw-parser-output tr+tr>.navbox-list{border-top:2px solid #fdfdfd}.mw-parser-output .navbox-title{background-color:#ccf}.mw-parser-output .navbox-abovebelow,.mw-parser-output .navbox-group,.mw-parser-output .navbox-subgroup .navbox-title{background-color:#ddf}.mw-parser-output .navbox-subgroup .navbox-group,.mw-parser-output .navbox-subgroup .navbox-abovebelow{background-color:#e6e6ff}.mw-parser-output .navbox-even{background-color:#f7f7f7}.mw-parser-output .navbox-odd{background-color:transparent}.mw-parser-output .navbox .hlist td dl,.mw-parser-output .navbox .hlist td ol,.mw-parser-output .navbox .hlist td ul,.mw-parser-output .navbox td.hlist dl,.mw-parser-output .navbox td.hlist ol,.mw-parser-output .navbox td.hlist ul{padding:0.125em 0}.mw-parser-output .navbox .navbar{display:block;font-size:100%}.mw-parser-output .navbox-title .navbar{float:left;text-align:left;margin-right:0.5em}body.skin--responsive .mw-parser-output .navbox-image img{max-width:none!important}@media print{body.ns-0 .mw-parser-output .navbox{display:none!important}}</style></div><div role="navigation" class="navbox" aria-labelledby="Heat_engines" style="padding:3px"><table class="nowraplinks mw-collapsible autocollapse navbox-inner" style="border-spacing:0;background:transparent;color:inherit"><tbody><tr><th scope="col" class="navbox-title" colspan="2" style="background:#F0DC82;"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"><style data-mw-deduplicate="TemplateStyles:r1239400231">.mw-parser-output .navbar{display:inline;font-size:88%;font-weight:normal}.mw-parser-output .navbar-collapse{float:left;text-align:left}.mw-parser-output .navbar-boxtext{word-spacing:0}.mw-parser-output .navbar ul{display:inline-block;white-space:nowrap;line-height:inherit}.mw-parser-output .navbar-brackets::before{margin-right:-0.125em;content:"[ "}.mw-parser-output .navbar-brackets::after{margin-left:-0.125em;content:" ]"}.mw-parser-output .navbar li{word-spacing:-0.125em}.mw-parser-output .navbar a>span,.mw-parser-output .navbar a>abbr{text-decoration:inherit}.mw-parser-output .navbar-mini abbr{font-variant:small-caps;border-bottom:none;text-decoration:none;cursor:inherit}.mw-parser-output .navbar-ct-full{font-size:114%;margin:0 7em}.mw-parser-output .navbar-ct-mini{font-size:114%;margin:0 4em}html.skin-theme-clientpref-night .mw-parser-output .navbar li a abbr{color:var(--color-base)!important}@media(prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .navbar li a abbr{color:var(--color-base)!important}}@media print{.mw-parser-output .navbar{display:none!important}}</style><div class="navbar plainlinks hlist navbar-mini"><ul><li class="nv-view"><a href="/wiki/Template:Heat_engines" title="Template:Heat engines"><abbr title="View this template">v</abbr></a></li><li class="nv-talk"><a href="/wiki/Template_talk:Heat_engines" title="Template talk:Heat engines"><abbr title="Discuss this template">t</abbr></a></li><li class="nv-edit"><a href="/wiki/Special:EditPage/Template:Heat_engines" title="Special:EditPage/Template:Heat engines"><abbr title="Edit this template">e</abbr></a></li></ul></div><div id="Heat_engines" style="font-size:114%;margin:0 4em"><a href="/wiki/Heat_engine" title="Heat engine">Heat engines</a></div></th></tr><tr><td colspan="2" class="navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Carnot_heat_engine" title="Carnot heat engine">Carnot engine</a></li> <li><a href="/wiki/Fluidyne_engine" title="Fluidyne engine">Fluidyne</a></li> <li><a href="/wiki/Gas_turbine" title="Gas turbine">Gas turbine</a></li> <li><a href="/wiki/Hot_air_engine" title="Hot air engine">Hot air</a></li> <li><a href="/wiki/Jet_engine" title="Jet engine">Jet</a></li> <li><a href="/wiki/Minto_wheel" title="Minto wheel">Minto wheel</a></li> <li><a href="/wiki/Photo-Carnot_engine" title="Photo-Carnot engine">Photo-Carnot engine</a></li> <li><a href="/wiki/Reciprocating_engine" title="Reciprocating engine">Piston</a></li> <li><a href="/wiki/Pistonless_rotary_engine" title="Pistonless rotary engine">Pistonless (Rotary)</a></li> <li><a href="/wiki/Rijke_tube" title="Rijke tube">Rijke tube</a></li> <li><a href="/wiki/Rocket_engine" title="Rocket engine">Rocket</a></li> <li><a href="/wiki/Split-single_engine" title="Split-single engine">Split-single</a></li> <li><a href="/wiki/Steam_engine" title="Steam engine">Steam (reciprocating)</a></li> <li><a href="/wiki/Steam_turbine" title="Steam turbine">Steam turbine</a> <ul><li><a href="/wiki/Aeolipile" title="Aeolipile">Aeolipile</a></li></ul></li> <li><a href="/wiki/Stirling_engine" title="Stirling engine">Stirling</a></li> <li><a href="/wiki/Thermoacoustic_heat_engine" title="Thermoacoustic heat engine">Thermoacoustic</a></li> <li><a href="/wiki/Manson_engine" title="Manson engine">Manson engine</a></li></ul> </div></td></tr><tr><td colspan="2" class="navbox-list navbox-even hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Beale_number" title="Beale number">Beale number</a></li> <li><a href="/wiki/West_number" title="West number">West number</a></li></ul> </div></td></tr><tr><td colspan="2" class="navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Timeline_of_heat_engine_technology" title="Timeline of heat engine technology">Timeline of heat engine technology</a></li></ul> </div></td></tr><tr><td class="navbox-abovebelow" colspan="2" style="background:#F0DC82;"><div><a href="/wiki/Thermodynamic_cycle" title="Thermodynamic cycle">Thermodynamic cycle</a></div></td></tr></tbody></table></div> <div class="navbox-styles"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236075235"></div><div role="navigation" class="navbox" aria-labelledby="Thermodynamic_cycles" style="padding:3px"><table class="nowraplinks mw-collapsible autocollapse navbox-inner" style="border-spacing:0;background:transparent;color:inherit"><tbody><tr><th scope="col" class="navbox-title" colspan="2"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1239400231"><div class="navbar plainlinks hlist navbar-mini"><ul><li class="nv-view"><a href="/wiki/Template:Thermodynamic_cycles" title="Template:Thermodynamic cycles"><abbr title="View this template">v</abbr></a></li><li class="nv-talk"><a href="/wiki/Template_talk:Thermodynamic_cycles" title="Template talk:Thermodynamic cycles"><abbr title="Discuss this template">t</abbr></a></li><li class="nv-edit"><a href="/wiki/Special:EditPage/Template:Thermodynamic_cycles" title="Special:EditPage/Template:Thermodynamic cycles"><abbr title="Edit this template">e</abbr></a></li></ul></div><div id="Thermodynamic_cycles" style="font-size:114%;margin:0 4em"><a href="/wiki/Thermodynamic_cycle" title="Thermodynamic cycle">Thermodynamic cycles</a></div></th></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/External_combustion_engine" title="External combustion engine">External<br />combustion / thermal</a></th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:1%;font-weight:normal;"><div style="display: inline-block; line-height: 1.2em; padding: .1em 0;">Without phase change<br />(<a href="/wiki/Hot_air_engine" title="Hot air engine">hot air engines</a>)</div></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Brayton_cycle#Reverse_Brayton_cycle" title="Brayton cycle">Bell Coleman</a></li> <li><a href="/wiki/Brayton_cycle" title="Brayton cycle">Brayton/Joule</a></li> <li><a href="/wiki/Carnot_cycle" title="Carnot cycle">Carnot</a></li> <li><a href="/wiki/Ericsson_cycle" title="Ericsson cycle">Ericsson</a></li> <li><a href="/wiki/Stirling_cycle" title="Stirling cycle">Stirling</a></li> <li><a href="/wiki/Pseudo_Stirling_cycle" title="Pseudo Stirling cycle">Stirling (pseudo/adiabatic)</a></li> <li><a href="/wiki/Stoddard_cycle" class="mw-redirect" title="Stoddard cycle">Stoddard</a></li> <li><a href="/wiki/Manson_engine" title="Manson engine">Manson</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%;font-weight:normal;">With phase change</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Kalina_cycle" title="Kalina cycle">Kalina</a></li> <li><a href="/wiki/Hygroscopic_cycle" title="Hygroscopic cycle">Hygroscopic</a></li> <li><a href="/wiki/Rankine_cycle" title="Rankine cycle">Rankine</a> (<a href="/wiki/Organic_Rankine_cycle" title="Organic Rankine cycle">Organic Rankine</a>)</li> <li><a href="/wiki/Regenerative_cycle" class="mw-redirect" title="Regenerative cycle">Regenerative</a></li></ul> </div></td></tr></tbody></table><div></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Internal_combustion_engine" title="Internal combustion engine">Internal <br />combustion / thermal</a></th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Atkinson_cycle" title="Atkinson cycle">Atkinson</a></li> <li><a href="/wiki/Brayton_cycle" title="Brayton cycle">Brayton/Joule</a></li> <li><a href="/wiki/Diesel_cycle" title="Diesel cycle">Diesel</a></li> <li><a href="/wiki/Expander_cycle" title="Expander cycle">Expander</a></li> <li><a href="/wiki/Gas-generator_cycle" title="Gas-generator cycle">Gas-generator</a></li> <li><a href="/wiki/Homogeneous_charge_compression_ignition" title="Homogeneous charge compression ignition">Homogeneous charge compression ignition</a></li> <li><a href="/wiki/Humphrey_cycle" title="Humphrey cycle">Humphrey</a></li> <li><a href="/wiki/Lenoir_cycle" title="Lenoir cycle">Lenoir</a></li> <li><a href="/wiki/Miller_cycle" title="Miller cycle">Miller</a></li> <li><a href="/wiki/Otto_cycle" title="Otto cycle">Otto</a></li> <li><a href="/wiki/Scuderi_cycle" title="Scuderi cycle">Scuderi</a></li> <li><a href="/wiki/Staged_combustion_cycle" title="Staged combustion cycle">Staged combustion</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Mixed</th><td class="navbox-list-with-group navbox-list navbox-even hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Combined_cycle" class="mw-redirect" title="Combined cycle">Combined</a></li> <li><a href="/wiki/High-efficiency_hybrid_cycle" title="High-efficiency hybrid cycle">HEHC</a></li> <li><a href="/wiki/Mixed/dual_cycle" title="Mixed/dual cycle">Mixed/dual</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Heat_pump_and_refrigeration_cycle" title="Heat pump and refrigeration cycle">Refrigeration</a></th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Hampson%E2%80%93Linde_cycle" title="Hampson–Linde cycle">Hampson–Linde</a></li> <li><a href="/wiki/Kleemenko_cycle" title="Kleemenko cycle">Kleemenko</a></li> <li><a href="/wiki/Pulse_tube_refrigerator" title="Pulse tube refrigerator">Pulse tube</a></li> <li><a href="/wiki/Regenerative_cooling" title="Regenerative cooling">Regenerative cooling</a></li> <li><a href="/wiki/Transcritical_cycle" title="Transcritical cycle">Transcritical</a></li> <li><a href="/wiki/Absorption_refrigerator" title="Absorption refrigerator">Vapor absorption</a></li> <li><a href="/wiki/Vapor-compression_refrigeration" title="Vapor-compression refrigeration">Vapor-compression</a></li> <li><a href="/wiki/Siemens_cycle" title="Siemens cycle">Siemens</a></li> <li><a href="/wiki/Vuilleumier_cycle" title="Vuilleumier cycle">Vuilleumier</a></li> <li><a href="/wiki/Ionocaloric_refrigeration" title="Ionocaloric refrigeration">Ionocaloric</a></li></ul> </div></td></tr></tbody></table></div> <div class="navbox-styles"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236075235"></div><div role="navigation" class="navbox" aria-labelledby="Internal_combustion_engine" style="padding:3px"><table class="nowraplinks mw-collapsible autocollapse navbox-inner" style="border-spacing:0;background:transparent;color:inherit"><tbody><tr><th scope="col" class="navbox-title" colspan="2"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1239400231"><div class="navbar plainlinks hlist navbar-mini"><ul><li class="nv-view"><a href="/wiki/Template:Internal_combustion_engine" title="Template:Internal combustion engine"><abbr title="View this template">v</abbr></a></li><li class="nv-talk"><a href="/wiki/Template_talk:Internal_combustion_engine" title="Template talk:Internal combustion engine"><abbr title="Discuss this template">t</abbr></a></li><li class="nv-edit"><a href="/wiki/Special:EditPage/Template:Internal_combustion_engine" title="Special:EditPage/Template:Internal combustion engine"><abbr title="Edit this template">e</abbr></a></li></ul></div><div id="Internal_combustion_engine" style="font-size:114%;margin:0 4em"><a href="/wiki/Internal_combustion_engine" title="Internal combustion engine">Internal combustion engine</a></div></th></tr><tr><td class="navbox-abovebelow" colspan="2"><div><i>Part of the <a href="/wiki/Car" title="Car">Automobile</a> series</i></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Engine_block" title="Engine block">Engine block</a> and<br /> rotating assembly</th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Balance_shaft" title="Balance shaft">Balance shaft</a></li> <li><a href="/wiki/Block_heater" title="Block heater">Block heater</a></li> <li><a href="/wiki/Bore_(engine)" title="Bore (engine)">Bore</a></li> <li><a href="/wiki/Connecting_rod" title="Connecting rod">Connecting rod</a></li> <li><a href="/wiki/Crankcase" title="Crankcase">Crankcase</a></li> <li><a href="/wiki/Crankcase_ventilation_system" title="Crankcase ventilation system">Crankcase ventilation system (PCV valve)</a></li> <li><a href="/wiki/Crankpin" title="Crankpin">Crankpin</a></li> <li><a href="/wiki/Crankshaft" title="Crankshaft">Crankshaft</a></li> <li><a href="/wiki/Core_plug" title="Core plug">Core plug (freeze plug)</a></li> <li><a href="/wiki/Cylinder_(engine)" title="Cylinder (engine)">Cylinder</a> (<a href="/wiki/Cylinder_bank" class="mw-redirect" title="Cylinder bank">bank</a>, <a href="/wiki/Engine_configuration" title="Engine configuration">layout</a>)</li> <li><a href="/wiki/Engine_displacement" title="Engine displacement">Displacement</a></li> <li><a href="/wiki/Flywheel" title="Flywheel">Flywheel</a></li> <li><a href="/wiki/Firing_order" title="Firing order">Firing order</a></li> <li><a href="/wiki/Stroke_(engine)" title="Stroke (engine)">Stroke</a></li> <li><a href="/wiki/Main_bearing" title="Main bearing">Main bearing</a></li> <li><a href="/wiki/Piston" title="Piston">Piston</a></li> <li><a href="/wiki/Piston_ring" title="Piston ring">Piston ring</a></li> <li><a href="/wiki/Starter_ring_gear" title="Starter ring gear">Starter ring gear</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Valvetrain" title="Valvetrain">Valvetrain</a> and<br /> <a href="/wiki/Cylinder_head" title="Cylinder head">Cylinder head</a></th><td class="navbox-list-with-group navbox-list navbox-even hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Flathead_engine" title="Flathead engine">Flathead layout</a></li> <li><a href="/wiki/Overhead_camshaft_engine" title="Overhead camshaft engine">Overhead camshaft layout</a></li> <li><a href="/wiki/Overhead_valve_engine" title="Overhead valve engine">Overhead valve (pushrod) layout</a></li></ul> <ul><li><a href="/wiki/Tappet" title="Tappet">Tappet / lifter</a></li> <li><a href="/wiki/Camshaft" title="Camshaft">Camshaft</a></li> <li><a href="/wiki/Chest_(mechanical_engineering)" title="Chest (mechanical engineering)">Chest</a></li> <li><a href="/wiki/Combustion_chamber" title="Combustion chamber">Combustion chamber</a></li> <li><a href="/wiki/Compression_ratio" title="Compression ratio">Compression ratio</a></li> <li><a href="/wiki/Head_gasket" title="Head gasket">Head gasket</a></li> <li><a href="/wiki/Rocker_arm" title="Rocker arm">Rocker arm</a></li> <li><a href="/wiki/Timing_belt_(camshaft)" title="Timing belt (camshaft)">Timing belt</a></li> <li><a href="/wiki/Poppet_valve" title="Poppet valve">Valve</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Forced_induction" title="Forced induction">Forced induction</a></th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Blowoff_valve" title="Blowoff valve">Blowoff valve</a></li> <li><a href="/wiki/Boost_controller" title="Boost controller">Boost controller</a></li> <li><a href="/wiki/Intercooler" title="Intercooler">Intercooler</a></li> <li><a href="/wiki/Supercharger" title="Supercharger">Supercharger</a></li> <li><a href="/wiki/Turbocharger" title="Turbocharger">Turbocharger</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Fuel system</th><td class="navbox-list-with-group navbox-list navbox-even hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Diesel_engine" title="Diesel engine">Diesel engine</a></li> <li><a href="/wiki/Petrol_engine" title="Petrol engine">Petrol engine</a></li> <li><a href="/wiki/Carburetor" title="Carburetor">Carburetor</a></li> <li><a href="/wiki/Fuel_filter" title="Fuel filter">Fuel filter</a></li> <li><a href="/wiki/Fuel_injection" title="Fuel injection">Fuel injection</a></li> <li><a href="/wiki/Fuel_pump" title="Fuel pump">Fuel pump</a></li> <li><a href="/wiki/Fuel_tank" title="Fuel tank">Fuel tank</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Ignition_system" title="Ignition system">Ignition</a></th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Ignition_magneto" title="Ignition magneto">Magneto</a></li> <li><a href="/wiki/Compression_ignition" class="mw-redirect" title="Compression ignition">Compression ignition</a></li> <li><a href="/wiki/Coil-on-plug_ignition" class="mw-redirect" title="Coil-on-plug ignition">Coil-on-plug</a></li> <li><a href="/wiki/Distributor" title="Distributor">Distributor</a></li> <li><a href="/wiki/Glow_plug_(diesel_engine)" class="mw-redirect" title="Glow plug (diesel engine)">Glow plug</a></li> <li><a href="/wiki/Ignition_coil" title="Ignition coil">Ignition coil</a></li> <li><a href="/wiki/Spark_plug" title="Spark plug">Spark plug</a></li> <li><a href="/wiki/Spark_plug_wires" title="Spark plug wires">Spark plug wires</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><div style="display: inline-block; line-height: 1.2em; padding: .1em 0;">Engine management</div></th><td class="navbox-list-with-group navbox-list navbox-even hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Engine_control_unit" title="Engine control unit">Engine control unit (ECU)</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><div style="display: inline-block; line-height: 1.2em; padding: .1em 0;">Electrical system</div></th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Alternator_(automotive)" title="Alternator (automotive)">Alternator</a></li> <li><a href="/wiki/Automotive_battery" title="Automotive battery">Battery</a></li> <li><a href="/wiki/Dynamo" title="Dynamo">Dynamo</a></li> <li><a href="/wiki/Starter_(engine)" title="Starter (engine)">Starter motor</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Intake system</th><td class="navbox-list-with-group navbox-list navbox-even hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Airbox" title="Airbox">Airbox</a></li> <li><a href="/wiki/Air_filter#Internal_combustion_engine_air_filters" title="Air filter">Air filter</a></li> <li><a href="/wiki/Idle_air_control_actuator" title="Idle air control actuator">Idle air control actuator</a></li> <li><a href="/wiki/Inlet_manifold" title="Inlet manifold">Inlet manifold</a></li> <li><a href="/wiki/MAP_sensor" title="MAP sensor">MAP sensor</a></li> <li><a href="/wiki/Mass_flow_sensor" title="Mass flow sensor">MAF sensor</a></li> <li><a href="/wiki/Throttle" title="Throttle">Throttle</a></li> <li><a href="/wiki/Throttle_position_sensor" title="Throttle position sensor">Throttle position sensor</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Exhaust_system" title="Exhaust system">Exhaust system</a></th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Catalytic_converter" title="Catalytic converter">Catalytic converter</a></li> <li><a href="/wiki/Diesel_particulate_filter" title="Diesel particulate filter">Diesel particulate filter</a></li> <li><a href="/wiki/Exhaust_gas_temperature_gauge" title="Exhaust gas temperature gauge">EGT sensor</a></li> <li><a href="/wiki/Exhaust_manifold" title="Exhaust manifold">Exhaust manifold</a></li> <li><a href="/wiki/Muffler" title="Muffler">Muffler</a></li> <li><a href="/wiki/Oxygen_sensor#Automotive_applications" title="Oxygen sensor">Oxygen sensor</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Internal_combustion_engine_cooling" title="Internal combustion engine cooling">Cooling system</a></th><td class="navbox-list-with-group navbox-list navbox-even hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Air_cooling" title="Air cooling">Air cooling</a></li> <li><a href="/wiki/Water_cooling" title="Water cooling">Water cooling</a></li></ul> <ul><li><a href="/wiki/Fan_(machine)" title="Fan (machine)">Electric fan</a></li> <li><a href="/wiki/Radiator_(engine_cooling)" title="Radiator (engine cooling)">Radiator</a></li> <li><a href="/wiki/Thermostat" title="Thermostat">Thermostat</a></li> <li><a href="/wiki/Fan_clutch" title="Fan clutch">Viscous fan (fan clutch)</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Lubrication</th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Motor_oil" title="Motor oil">Oil</a></li> <li><a href="/wiki/Oil_filter" title="Oil filter">Oil filter</a></li> <li><a href="/wiki/Oil_pump_(internal_combustion_engine)" title="Oil pump (internal combustion engine)">Oil pump</a></li> <li><a href="/wiki/Sump" title="Sump">Sump</a> (<a href="/wiki/Wet_sump" title="Wet sump">Wet sump</a>, <a href="/wiki/Dry_sump" title="Dry sump">Dry sump</a>)</li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Other</th><td class="navbox-list-with-group navbox-list navbox-even hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Engine_knocking" title="Engine knocking">Knocking / pinging</a></li> <li><a href="/wiki/Power_band" title="Power band">Power band</a></li> <li><a href="/wiki/Redline" title="Redline">Redline</a></li> <li><a href="/wiki/Stratified_charge_engine" title="Stratified charge engine">Stratified charge</a></li> <li><a href="/wiki/Dead_centre_(engineering)" title="Dead centre (engineering)">Top dead centre</a></li></ul> </div></td></tr><tr><td class="navbox-abovebelow hlist" colspan="2" style="font-weight:bold;"><div> <ul><li><a href="/wiki/Portal:Cars" title="Portal:Cars">Portal</a></li> <li><a href="/wiki/Category:Cars" title="Category:Cars">Category</a></li></ul> </div></td></tr></tbody></table></div>    </div><noscript><img src="https://login.wikimedia.org/wiki/Special:CentralAutoLogin/start?useformat=desktop&type=1x1&usesul3=0" alt="" width="1" height="1" style="border: none; position: absolute;"></noscript> <div class="printfooter" data-nosnippet="">Retrieved from "<a dir="ltr" href="https://en.wikipedia.org/w/index.php?title=Stroke_ratio&oldid=1258125692#Undersquare">https://en.wikipedia.org/w/index.php?title=Stroke_ratio&oldid=1258125692#Undersquare</a>"</div></div> <div id="catlinks" class="catlinks" data-mw="interface"><div id="mw-normal-catlinks" class="mw-normal-catlinks"><a href="/wiki/Help:Category" title="Help:Category">Categories</a>: <ul><li><a href="/wiki/Category:Engine_technology" title="Category:Engine technology">Engine technology</a></li><li><a href="/wiki/Category:Piston_engines" title="Category:Piston engines">Piston engines</a></li><li><a href="/wiki/Category:Engineering_ratios" title="Category:Engineering ratios">Engineering ratios</a></li></ul></div><div id="mw-hidden-catlinks" class="mw-hidden-catlinks mw-hidden-cats-hidden">Hidden categories: <ul><li><a href="/wiki/Category:All_articles_with_unsourced_statements" title="Category:All articles with unsourced statements">All articles with unsourced statements</a></li><li><a href="/wiki/Category:Articles_with_unsourced_statements_from_November_2023" title="Category:Articles with unsourced statements from November 2023">Articles with unsourced statements from November 2023</a></li><li><a href="/wiki/Category:Articles_with_short_description" title="Category:Articles with short description">Articles with short description</a></li><li><a href="/wiki/Category:Short_description_is_different_from_Wikidata" title="Category:Short description is different from Wikidata">Short description is different from Wikidata</a></li><li><a href="/wiki/Category:Articles_needing_additional_references_from_August_2009" title="Category:Articles needing additional references from August 2009">Articles needing additional references from August 2009</a></li><li><a href="/wiki/Category:All_articles_needing_additional_references" title="Category:All articles needing additional references">All articles needing additional references</a></li><li><a href="/wiki/Category:Use_dmy_dates_from_April_2022" title="Category:Use dmy dates from April 2022">Use dmy dates from April 2022</a></li><li><a href="/wiki/Category:Articles_with_too_many_examples_from_November_2023" title="Category:Articles with too many examples from November 2023">Articles with too many examples from November 2023</a></li><li><a href="/wiki/Category:All_articles_with_too_many_examples" title="Category:All articles with too many examples">All articles with too many examples</a></li><li><a href="/wiki/Category:Wikipedia_articles_with_style_issues_from_November_2023" title="Category:Wikipedia articles with style issues from November 2023">Wikipedia articles with style issues from November 2023</a></li><li><a href="/wiki/Category:All_Wikipedia_articles_needing_clarification" title="Category:All Wikipedia articles needing clarification">All Wikipedia articles needing clarification</a></li><li><a href="/wiki/Category:Wikipedia_articles_needing_clarification_from_November_2023" title="Category:Wikipedia articles needing clarification from November 2023">Wikipedia articles needing clarification from November 2023</a></li><li><a href="/wiki/Category:Commons_category_link_is_locally_defined" title="Category:Commons category link is locally defined">Commons category link is locally defined</a></li></ul></div></div> </div> </main> </div> <div class="mw-footer-container"> <footer id="footer" class="mw-footer" > <ul id="footer-info"> <li id="footer-info-lastmod"> This page was last edited on 18 November 2024, at 07:16<span class="anonymous-show"> (UTC)</span>.</li> <li id="footer-info-copyright">Text is available under the <a href="/wiki/Wikipedia:Text_of_the_Creative_Commons_Attribution-ShareAlike_4.0_International_License" title="Wikipedia:Text of the Creative Commons Attribution-ShareAlike 4.0 International License">Creative Commons Attribution-ShareAlike 4.0 License</a>; additional terms may apply. By using this site, you agree to the <a href="https://foundation.wikimedia.org/wiki/Special:MyLanguage/Policy:Terms_of_Use" class="extiw" title="foundation:Special:MyLanguage/Policy:Terms of Use">Terms of Use</a> and <a href="https://foundation.wikimedia.org/wiki/Special:MyLanguage/Policy:Privacy_policy" class="extiw" title="foundation:Special:MyLanguage/Policy:Privacy policy">Privacy Policy</a>. Wikipedia® is a registered trademark of the <a rel="nofollow" class="external text" href="https://wikimediafoundation.org/">Wikimedia Foundation, Inc.</a>, a non-profit organization.</li> </ul> <ul id="footer-places"> <li id="footer-places-privacy"><a href="https://foundation.wikimedia.org/wiki/Special:MyLanguage/Policy:Privacy_policy">Privacy policy</a></li> <li id="footer-places-about"><a href="/wiki/Wikipedia:About">About Wikipedia</a></li> <li id="footer-places-disclaimers"><a href="/wiki/Wikipedia:General_disclaimer">Disclaimers</a></li> <li id="footer-places-contact"><a href="//en.wikipedia.org/wiki/Wikipedia:Contact_us">Contact Wikipedia</a></li> <li id="footer-places-wm-codeofconduct"><a href="https://foundation.wikimedia.org/wiki/Special:MyLanguage/Policy:Universal_Code_of_Conduct">Code of Conduct</a></li> <li id="footer-places-developers"><a href="https://developer.wikimedia.org">Developers</a></li> <li id="footer-places-statslink"><a href="https://stats.wikimedia.org/#/en.wikipedia.org">Statistics</a></li> <li id="footer-places-cookiestatement"><a href="https://foundation.wikimedia.org/wiki/Special:MyLanguage/Policy:Cookie_statement">Cookie statement</a></li> <li id="footer-places-mobileview"><a href="//en.m.wikipedia.org/w/index.php?title=Stroke_ratio&mobileaction=toggle_view_mobile#Undersquare" class="noprint stopMobileRedirectToggle">Mobile view</a></li> </ul> <ul id="footer-icons" class="noprint"> <li id="footer-copyrightico"><a href="https://wikimediafoundation.org/" class="cdx-button cdx-button--fake-button cdx-button--size-large cdx-button--fake-button--enabled"><img src="/static/images/footer/wikimedia-button.svg" width="84" height="29" alt="Wikimedia Foundation" loading="lazy"></a></li> <li id="footer-poweredbyico"><a href="https://www.mediawiki.org/" class="cdx-button cdx-button--fake-button cdx-button--size-large cdx-button--fake-button--enabled"><img src="/w/resources/assets/poweredby_mediawiki.svg" alt="Powered by MediaWiki" width="88" height="31" loading="lazy"></a></li> </ul> </footer> </div> </div> </div> <div class="vector-settings" id="p-dock-bottom"> <ul></ul> </div><script>(RLQ=window.RLQ||[]).push(function(){mw.config.set({"wgHostname":"mw-web.codfw.main-f68f4df69-8bp7l","wgBackendResponseTime":160,"wgPageParseReport":{"limitreport":{"cputime":"0.464","walltime":"0.589","ppvisitednodes":{"value":2442,"limit":1000000},"postexpandincludesize":{"value":85656,"limit":2097152},"templateargumentsize":{"value":3889,"limit":2097152},"expansiondepth":{"value":14,"limit":100},"expensivefunctioncount":{"value":7,"limit":500},"unstrip-depth":{"value":1,"limit":20},"unstrip-size":{"value":66341,"limit":5000000},"entityaccesscount":{"value":1,"limit":400},"timingprofile":["100.00% 504.064 1 -total"," 29.87% 150.563 2 Template:Reflist"," 17.29% 87.132 4 Template:Navbox"," 15.02% 75.731 1 Template:Heat_engines"," 14.71% 74.163 1 Template:Cite_journal"," 11.62% 58.592 1 Template:Short_description"," 11.14% 56.141 1 Template:More_citations_needed"," 10.62% 53.511 2 Template:Ambox"," 9.97% 50.267 1 Template:Commons_category"," 9.58% 48.301 1 Template:Sister_project"]},"scribunto":{"limitreport-timeusage":{"value":"0.279","limit":"10.000"},"limitreport-memusage":{"value":8669005,"limit":52428800}},"cachereport":{"origin":"mw-web.codfw.main-5857dfdcd6-2qvcz","timestamp":"20241203070938","ttl":2592000,"transientcontent":false}}});});</script> <script type="application/ld+json">{"@context":"https:\/\/schema.org","@type":"Article","name":"Stroke ratio","url":"https:\/\/en.wikipedia.org\/wiki\/Stroke_ratio#Undersquare","sameAs":"http:\/\/www.wikidata.org\/entity\/Q844463","mainEntity":"http:\/\/www.wikidata.org\/entity\/Q844463","author":{"@type":"Organization","name":"Contributors to Wikimedia projects"},"publisher":{"@type":"Organization","name":"Wikimedia Foundation, Inc.","logo":{"@type":"ImageObject","url":"https:\/\/www.wikimedia.org\/static\/images\/wmf-hor-googpub.png"}},"datePublished":"2005-10-05T21:22:24Z","dateModified":"2024-11-18T07:16:42Z","image":"https:\/\/upload.wikimedia.org\/wikipedia\/commons\/b\/bf\/Bore_Stroke_Ratio_Animation.gif","headline":"mechanics term"}</script> </body> </html>