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>U engine - 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":"d33e66b0-38bf-40d1-b5bb-3f469ecb0800","wgCanonicalNamespace":"","wgCanonicalSpecialPageName":false,"wgNamespaceNumber":0,"wgPageName":"U_engine","wgTitle":"U engine","wgCurRevisionId":1259241374,"wgRevisionId":1259241374,"wgArticleId":877975,"wgIsArticle":true,"wgIsRedirect":false,"wgAction":"view","wgUserName":null,"wgUserGroups":["*"],"wgCategories":["All articles with dead external links","Articles with dead external links from February 2022","Articles with short description","Short description is different from Wikidata","Articles needing additional references from December 2023","All articles needing additional references","All articles with unsourced statements","Articles with unsourced statements from December 2023","Articles with unsourced statements from April 2021","Commons category link is on Wikidata","Piston engine configurations" ,"U engines","Engines by cylinder layout"],"wgPageViewLanguage":"en","wgPageContentLanguage":"en","wgPageContentModel":"wikitext","wgRelevantPageName":"U_engine","wgRelevantArticleId":877975,"wgIsProbablyEditable":true,"wgRelevantPageIsProbablyEditable":true,"wgRestrictionEdit":[],"wgRestrictionMove":[],"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":10000,"wgRelatedArticlesCompat":[],"wgCentralAuthMobileDomain":false,"wgEditSubmitButtonLabelPublish":true,"wgULSPosition":"interlanguage","wgULSisCompactLinksEnabled":false,"wgVector2022LanguageInHeader":true, "wgULSisLanguageSelectorEmpty":false,"wgWikibaseItemId":"Q1536514","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=["ext.cite.ux-enhancements","mediawiki.page.media","ext.scribunto.logs","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.quicksurveys.init","ext.growthExperiments.SuggestedEditSession","wikibase.sidebar.tracking"];</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.4"> <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/2/2b/U-Engine.gif"> <meta property="og:image:width" content="1200"> <meta property="og:image:height" content="1244"> <meta property="og:image" content="https://upload.wikimedia.org/wikipedia/commons/2/2b/U-Engine.gif"> <meta property="og:image:width" content="800"> <meta property="og:image:height" content="829"> <meta property="og:image:width" content="640"> <meta property="og:image:height" content="663"> <meta name="viewport" content="width=1120"> <meta property="og:title" content="U engine - 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/U_engine"> <link rel="alternate" type="application/x-wiki" title="Edit this page" href="/w/index.php?title=U_engine&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/U_engine"> <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-U_engine rootpage-U_engine 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/wiki/Special:FundraiserRedirector?utm_source=donate&utm_medium=sidebar&utm_campaign=C13_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=U+engine" 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=U+engine" 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/wiki/Special:FundraiserRedirector?utm_source=donate&utm_medium=sidebar&utm_campaign=C13_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=U+engine" 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=U+engine" 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-Design" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Design"> <div class="vector-toc-text"> <span class="vector-toc-numb">1</span> <span>Design</span> </div> </a> <ul id="toc-Design-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-History" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#History"> <div class="vector-toc-text"> <span class="vector-toc-numb">2</span> <span>History</span> </div> </a> <button aria-controls="toc-History-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 History subsection</span> </button> <ul id="toc-History-sublist" class="vector-toc-list"> <li id="toc-Petrol_engines" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Petrol_engines"> <div class="vector-toc-text"> <span class="vector-toc-numb">2.1</span> <span>Petrol engines</span> </div> </a> <ul id="toc-Petrol_engines-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Diesel" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Diesel"> <div class="vector-toc-text"> <span class="vector-toc-numb">2.2</span> <span>Diesel</span> </div> </a> <ul id="toc-Diesel-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> <li id="toc-Variations" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Variations"> <div class="vector-toc-text"> <span class="vector-toc-numb">3</span> <span>Variations</span> </div> </a> <button aria-controls="toc-Variations-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 Variations subsection</span> </button> <ul id="toc-Variations-sublist" class="vector-toc-list"> <li id="toc-Tandem_twin_engine" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Tandem_twin_engine"> <div class="vector-toc-text"> <span class="vector-toc-numb">3.1</span> <span>Tandem twin engine</span> </div> </a> <ul id="toc-Tandem_twin_engine-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Single_crankshaft" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Single_crankshaft"> <div class="vector-toc-text"> <span class="vector-toc-numb">3.2</span> <span>Single crankshaft</span> </div> </a> <ul id="toc-Single_crankshaft-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> <li id="toc-See_also" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#See_also"> <div class="vector-toc-text"> <span class="vector-toc-numb">4</span> <span>See also</span> </div> </a> <ul id="toc-See_also-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">5</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">U engine</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 15 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-15" 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">15 languages</span> </label> <div class="vector-dropdown-content"> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li class="interlanguage-link interwiki-ar mw-list-item"><a href="https://ar.wikipedia.org/wiki/%D9%85%D8%AD%D8%B1%D9%83_%D8%B4%D9%83%D9%84_U" title="محرك شكل U – Arabic" lang="ar" hreflang="ar" data-title="محرك شكل U" data-language-autonym="العربية" data-language-local-name="Arabic" class="interlanguage-link-target"><span>العربية</span></a></li><li class="interlanguage-link interwiki-cs mw-list-item"><a href="https://cs.wikipedia.org/wiki/Motor_s_v%C3%A1lci_do_U" title="Motor s válci do U – Czech" lang="cs" hreflang="cs" data-title="Motor s válci do U" data-language-autonym="Čeština" data-language-local-name="Czech" class="interlanguage-link-target"><span>Čeština</span></a></li><li class="interlanguage-link interwiki-de mw-list-item"><a href="https://de.wikipedia.org/wiki/U-Motor" title="U-Motor – German" lang="de" hreflang="de" data-title="U-Motor" 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/Motor_en_U" title="Motor en U – Spanish" lang="es" hreflang="es" data-title="Motor en U" 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/Motore_a_U" title="Motore a U – Italian" lang="it" hreflang="it" data-title="Motore a U" 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/U-motor" title="U-motor – Dutch" lang="nl" hreflang="nl" data-title="U-motor" 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/U%E5%9E%8B%E3%82%A8%E3%83%B3%E3%82%B8%E3%83%B3" title="U型エンジン – Japanese" lang="ja" hreflang="ja" data-title="U型エンジン" 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-no mw-list-item"><a href="https://no.wikipedia.org/wiki/U-motor" title="U-motor – Norwegian Bokmål" lang="nb" hreflang="nb" data-title="U-motor" data-language-autonym="Norsk bokmål" data-language-local-name="Norwegian Bokmål" class="interlanguage-link-target"><span>Norsk bokmål</span></a></li><li class="interlanguage-link interwiki-pt mw-list-item"><a href="https://pt.wikipedia.org/wiki/Motor_em_U" title="Motor em U – Portuguese" lang="pt" hreflang="pt" data-title="Motor em U" data-language-autonym="Português" data-language-local-name="Portuguese" class="interlanguage-link-target"><span>Português</span></a></li><li class="interlanguage-link interwiki-ru mw-list-item"><a href="https://ru.wikipedia.org/wiki/U-%D0%BE%D0%B1%D1%80%D0%B0%D0%B7%D0%BD%D1%8B%D0%B9_%D0%B4%D0%B2%D0%B8%D0%B3%D0%B0%D1%82%D0%B5%D0%BB%D1%8C" title="U-образный двигатель – Russian" lang="ru" hreflang="ru" data-title="U-образный двигатель" data-language-autonym="Русский" data-language-local-name="Russian" class="interlanguage-link-target"><span>Русский</span></a></li><li class="interlanguage-link interwiki-sk mw-list-item"><a href="https://sk.wikipedia.org/wiki/Motor_s_valcami_do_U" title="Motor s valcami do U – Slovak" lang="sk" hreflang="sk" data-title="Motor s valcami do U" data-language-autonym="Slovenčina" data-language-local-name="Slovak" class="interlanguage-link-target"><span>Slovenčina</span></a></li><li class="interlanguage-link interwiki-sl mw-list-item"><a href="https://sl.wikipedia.org/wiki/U-motor" title="U-motor – Slovenian" lang="sl" hreflang="sl" data-title="U-motor" data-language-autonym="Slovenščina" data-language-local-name="Slovenian" class="interlanguage-link-target"><span>Slovenščina</span></a></li><li class="interlanguage-link interwiki-sv mw-list-item"><a href="https://sv.wikipedia.org/wiki/U-motor" title="U-motor – Swedish" lang="sv" hreflang="sv" data-title="U-motor" data-language-autonym="Svenska" data-language-local-name="Swedish" class="interlanguage-link-target"><span>Svenska</span></a></li><li class="interlanguage-link interwiki-uk mw-list-item"><a href="https://uk.wikipedia.org/wiki/U-%D0%BF%D0%BE%D0%B4%D1%96%D0%B1%D0%BD%D0%B8%D0%B9_%D0%B4%D0%B2%D0%B8%D0%B3%D1%83%D0%BD" title="U-подібний двигун – Ukrainian" lang="uk" hreflang="uk" data-title="U-подібний двигун" data-language-autonym="Українська" data-language-local-name="Ukrainian" class="interlanguage-link-target"><span>Українська</span></a></li><li class="interlanguage-link interwiki-zh mw-list-item"><a href="https://zh.wikipedia.org/wiki/U%E5%9E%8B%E5%8F%91%E5%8A%A8%E6%9C%BA" title="U型发动机 – Chinese" lang="zh" hreflang="zh" data-title="U型发动机" data-language-autonym="中文" data-language-local-name="Chinese" class="interlanguage-link-target"><span>中文</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/Q1536514#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/U_engine" 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:U_engine" 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/U_engine"><span>Read</span></a></li><li id="ca-edit" class="vector-tab-noicon mw-list-item"><a href="/w/index.php?title=U_engine&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=U_engine&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/U_engine"><span>Read</span></a></li><li id="ca-more-edit" class="vector-more-collapsible-item mw-list-item"><a href="/w/index.php?title=U_engine&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=U_engine&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/U_engine" 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/U_engine" 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=U_engine&oldid=1259241374" 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=U_engine&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=U_engine&id=1259241374&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:UrlShortener&url=https%3A%2F%2Fen.wikipedia.org%2Fwiki%2FU_engine"><span>Get shortened URL</span></a></li><li id="t-urlshortener-qrcode" class="mw-list-item"><a href="/w/index.php?title=Special:QrCode&url=https%3A%2F%2Fen.wikipedia.org%2Fwiki%2FU_engine"><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=U_engine&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=U_engine&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:U_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/Q1536514" 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"></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">Piston engine design</div> <style data-mw-deduplicate="TemplateStyles:r1237032888/mw-parser-output/.tmulti">.mw-parser-output .tmulti .multiimageinner{display:flex;flex-direction:column}.mw-parser-output .tmulti .trow{display:flex;flex-direction:row;clear:left;flex-wrap:wrap;width:100%;box-sizing:border-box}.mw-parser-output .tmulti .tsingle{margin:1px;float:left}.mw-parser-output .tmulti .theader{clear:both;font-weight:bold;text-align:center;align-self:center;background-color:transparent;width:100%}.mw-parser-output .tmulti .thumbcaption{background-color:transparent}.mw-parser-output .tmulti .text-align-left{text-align:left}.mw-parser-output .tmulti .text-align-right{text-align:right}.mw-parser-output .tmulti .text-align-center{text-align:center}@media all and (max-width:720px){.mw-parser-output .tmulti .thumbinner{width:100%!important;box-sizing:border-box;max-width:none!important;align-items:center}.mw-parser-output .tmulti .trow{justify-content:center}.mw-parser-output .tmulti .tsingle{float:none!important;max-width:100%!important;box-sizing:border-box;text-align:center}.mw-parser-output .tmulti .tsingle .thumbcaption{text-align:left}.mw-parser-output .tmulti .trow>.thumbcaption{text-align:center}}@media screen{html.skin-theme-clientpref-night .mw-parser-output .tmulti .multiimageinner img{background-color:white}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .tmulti .multiimageinner img{background-color:white}}</style><div class="thumb tmulti tright"><div class="thumbinner multiimageinner" style="width:224px;max-width:224px"><div class="trow"><div class="tsingle" style="width:222px;max-width:222px"><div class="thumbimage"><span typeof="mw:File"><a href="/wiki/File:U-Engine.gif" class="mw-file-description"><img alt="" src="//upload.wikimedia.org/wikipedia/commons/thumb/2/2b/U-Engine.gif/220px-U-Engine.gif" decoding="async" width="220" height="228" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/2/2b/U-Engine.gif 1.5x" data-file-width="248" data-file-height="257" /></a></span></div><div class="thumbcaption">Animation of a U engine</div></div></div></div></div> <p>A <b>U engine</b> is a <a href="/wiki/Piston_engine" class="mw-redirect" title="Piston engine">piston engine</a> made up of two separate <a href="/wiki/Straight_engine" title="Straight engine">straight engines</a> (complete with separate crankshafts) placed side-by-side and coupled to a shared output shaft. When viewed from the front, the engine block resembles the letter "U". </p><p>Although much less common than the similar <a href="/wiki/V_engine" title="V engine">V engine</a> design, several U engines were produced from 1915 to 1987 for use in airplanes, racing cars, <a href="/wiki/Suzuki_RG_500" title="Suzuki RG 500">racing</a> and <a href="/wiki/Suzuki_RG500" title="Suzuki RG500">road</a> motorcycles, locomotives, and tanks. </p> <meta property="mw:PageProp/toc" /> <div class="mw-heading mw-heading2"><h2 id="Design">Design</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=U_engine&action=edit&section=1" title="Edit section: Design"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></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-Unreferenced_section plainlinks metadata ambox ambox-content ambox-Unreferenced" 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 section <b>does not <a href="/wiki/Wikipedia:Citing_sources" title="Wikipedia:Citing sources">cite</a> any <a href="/wiki/Wikipedia:Verifiability" title="Wikipedia:Verifiability">sources</a></b>.<span class="hide-when-compact"> Please help <a href="/wiki/Special:EditPage/U_engine" title="Special:EditPage/U engine">improve this section</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 <a href="/wiki/Wikipedia:Verifiability#Burden_of_evidence" title="Wikipedia:Verifiability">removed</a>.</span> <span class="date-container"><i>(<span class="date">December 2023</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>The main benefit of a U engine layout is the ability to share common parts with a straight engine upon which is it based. Additionally, if the two crankshafts rotate in opposite directions, the <a href="/wiki/Gyroscopic_effect" class="mw-redirect" title="Gyroscopic effect">gyroscopic effect</a> of the rotating components in each cylinder bank cancel each other out. </p><p>A V engine is typically more compact and lighter than a U engine, in part due to the lack of a second <a href="/wiki/Crankshaft" title="Crankshaft">crankshaft</a>, making V engines far more common than U engines. However, the V engine does not cancel the gyroscopic effect. </p><p>The <a href="/wiki/H_engine" title="H engine">H engine</a> layout uses a similar concept to U engines, whereby two <a href="/wiki/Flat_engine" title="Flat engine">flat engines</a> are stacked vertically. </p> <div class="mw-heading mw-heading2"><h2 id="History">History</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=U_engine&action=edit&section=2" title="Edit section: History"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <div class="mw-heading mw-heading3"><h3 id="Petrol_engines">Petrol engines</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=U_engine&action=edit&section=3" title="Edit section: Petrol engines"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <figure class="mw-default-size mw-halign-right" typeof="mw:File/Thumb"><a href="/wiki/File:King-Bugatti_U16_2.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/5/50/King-Bugatti_U16_2.jpg/220px-King-Bugatti_U16_2.jpg" decoding="async" width="220" height="165" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/5/50/King-Bugatti_U16_2.jpg/330px-King-Bugatti_U16_2.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/5/50/King-Bugatti_U16_2.jpg/440px-King-Bugatti_U16_2.jpg 2x" data-file-width="1600" data-file-height="1199" /></a><figcaption>1915–1916 <a href="/wiki/Bugatti_U-16" title="Bugatti U-16">Bugatti U-16</a> aircraft engine</figcaption></figure> <p>The first U engine known to have been built was the 1915–1916 <a href="/wiki/Bugatti_U-16" title="Bugatti U-16">Bugatti U-16</a> aircraft engine, which had 16 cylinders and a displacement of 24.3 L (1,483 cu in).<sup id="cite_ref-L’Ebe_1-0" class="reference"><a href="#cite_note-L’Ebe-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup> Approximately 40 engines were built at the <a href="/wiki/Duesenberg" title="Duesenberg">Duesenberg</a> factory in the United States during World War I.<sup id="cite_ref-racer_2-0" class="reference"><a href="#cite_note-racer-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup> A small number of engines based on the Bugatti U engine were also produced after the war by <a href="/wiki/Breguet_Aviation" title="Breguet Aviation">Breguet Aviation</a> in France.<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>The <i>Fiat 806</i> was a 1927 Grand Prix racing car that was powered by a 1.5 L (92 cu in) twelve-cylinder U engine.<sup id="cite_ref-Ludvigsen_4-0" class="reference"><a href="#cite_note-Ludvigsen-4"><span class="cite-bracket">[</span>4<span class="cite-bracket">]</span></a></sup> This engine, designated the 'Type 406', used a supercharger and had a single centrally-mounted intake camshaft which operated the intake valves located on the inside of each cylinder bank.<sup id="cite_ref-Fornaca,_1929_5-0" class="reference"><a href="#cite_note-Fornaca,_1929-5"><span class="cite-bracket">[</span>5<span class="cite-bracket">]</span></a></sup> Two separate camshafts operated the exhaust valves (one per bank). On test the unit delivered 187 bhp at 8,500 rpm at maximum boost.<sup id="cite_ref-Ludvigsen_4-1" class="reference"><a href="#cite_note-Ludvigsen-4"><span class="cite-bracket">[</span>4<span class="cite-bracket">]</span></a></sup> The Fiat 806 car competed in only one race, the 50 km (31 mi) Milan Grand Prix on 4 September 1927 (not to be confused with the 500 km <a href="/wiki/1927_Italian_Grand_Prix" title="1927 Italian Grand Prix">1927 Italian Grand Prix</a> held on the same day). The race was won by the Fiat 806; however, Fiat then retired from Grand Prix racing and the Type 806 did not race again.<sup id="cite_ref-6" class="reference"><a href="#cite_note-6"><span class="cite-bracket">[</span>6<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-7" class="reference"><a href="#cite_note-7"><span class="cite-bracket">[</span>7<span class="cite-bracket">]</span></a></sup> </p><p>The 1931–1959 <a href="/wiki/Ariel_Square_Four" title="Ariel Square Four">Ariel Square Four</a> motorcycle used a four-cylinder engine (also called a 'square four' engine). The engine was compact and had as narrow a frontal area as a 500 cc, parallel twin. The rear pair of cylinders on this air-cooled engine were prone to overheating.<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. (December 2023)">citation needed</span></a></i>]</sup> </p><p>The 1985–1987 <a href="/wiki/Suzuki_RG500" title="Suzuki RG500">Suzuki RG500</a> motorcycle, and several related racing motorcycles, used a water-cooled four-cylinder U engine. Although some racing success was achieved, the road bikes did not sell well and the design was phased out in favour of a conventional inline-four engine.<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. (December 2023)">citation needed</span></a></i>]</sup> </p> <div class="mw-heading mw-heading3"><h3 id="Diesel">Diesel</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=U_engine&action=edit&section=4" title="Edit section: Diesel"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>In the 1930s <a href="/wiki/Sulzer_Brothers_Ltd." class="mw-redirect" title="Sulzer Brothers Ltd.">Sulzer Brothers Ltd.</a> began production of an 'LD series' twelve-cylinder U engine for use in rail locomotives. The LD series was replaced by the LDA series, for a combined production period of over 50 years. The Sulzer 12LDA twin-bank engine formed the mainstay of British locomotives built in the 1960s, with over 700 used in the <a href="/wiki/British_Rail_Class_45" title="British Rail Class 45"><i>Peak</i></a> and <a href="/wiki/British_Rail_Class_47" title="British Rail Class 47">Class 47</a> locomotives.<sup id="cite_ref-8" class="reference"><a href="#cite_note-8"><span class="cite-bracket">[</span>8<span class="cite-bracket">]</span></a></sup> The Sulzer LDA engine used a smaller gear for the central output shaft than the two gears attached to the crankshaft. This resulted in the output shaft rotating at approximately 1000 rpm while the crankshafts rotated at approximately 750 rpm. The purpose of this gearing was to allow the use of a smaller, and lighter, electrical generator when the engine was used in a <a href="/wiki/Diesel-electric_locomotive" class="mw-redirect" title="Diesel-electric locomotive">diesel-electric locomotive</a>. </p><p>The <a href="/wiki/Detroit_Diesel_Series_71#WWII_General_Motors_6004/6046_engine" title="Detroit Diesel Series 71">General Motors 6046</a> is a twin-engine setup that was used by <a href="/wiki/Sherman_tank" class="mw-redirect" title="Sherman tank">Sherman tanks</a> during World War II. The 6046 was built using two straight-six engines that were separately clutched to a single output shaft, which was itself clutched to the transmission unit. A total of 10,968 6046D-powered M4A2 Shermans were produced.<sup id="cite_ref-9" class="reference"><a href="#cite_note-9"><span class="cite-bracket">[</span>9<span class="cite-bracket">]</span></a></sup> After World War II, several Soviet Union tanks powered by 16-cylinder and 18-cylinder engines that were reverse-engineered from the General Motors 6046 engine. These Soviet engines were designated Russkiy Dizel (Diesel Energo) DPN23/2H30 and the DRPN23/2H30.<sup id="cite_ref-10" class="reference"><a href="#cite_note-10"><span class="cite-bracket">[</span>10<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-11" class="reference"><a href="#cite_note-11"><span class="cite-bracket">[</span>11<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading2"><h2 id="Variations">Variations</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=U_engine&action=edit&section=5" title="Edit section: Variations"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <div class="mw-heading mw-heading3"><h3 id="Tandem_twin_engine">Tandem twin engine</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=U_engine&action=edit&section=6" title="Edit section: Tandem twin engine"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <figure class="mw-default-size mw-halign-right" typeof="mw:File/Thumb"><a href="/wiki/File:1976_Kawasaki_KR250_02.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/2/22/1976_Kawasaki_KR250_02.jpg/220px-1976_Kawasaki_KR250_02.jpg" decoding="async" width="220" height="165" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/2/22/1976_Kawasaki_KR250_02.jpg/330px-1976_Kawasaki_KR250_02.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/2/22/1976_Kawasaki_KR250_02.jpg/440px-1976_Kawasaki_KR250_02.jpg 2x" data-file-width="2832" data-file-height="2128" /></a><figcaption>A tandem inline-twin</figcaption></figure> <p>A tandem twin engine, occasionally used in motorcycles and go-karts, is a two-cylinder engine which uses a similar design to U engines. The motor has two crankshafts,<sup id="cite_ref-12" class="reference"><a href="#cite_note-12"><span class="cite-bracket">[</span>12<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-13" class="reference"><a href="#cite_note-13"><span class="cite-bracket">[</span>13<span class="cite-bracket">]</span></a></sup> one for each cylinder<sup id="cite_ref-14" class="reference"><a href="#cite_note-14"><span class="cite-bracket">[</span>14<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-15" class="reference"><a href="#cite_note-15"><span class="cite-bracket">[</span>15<span class="cite-bracket">]</span></a></sup> which are joined and kept in co-ordination by load carrying, crank-phasing gears connecting the two cylinders.<sup id="cite_ref-16" class="reference"><a href="#cite_note-16"><span class="cite-bracket">[</span>16<span class="cite-bracket">]</span></a></sup> </p><p>The tandem twin layout is used only with <a href="/wiki/Two-stroke_engine" title="Two-stroke engine">two-stroke engines</a> since these must have a discrete crankcase chamber per cylinder. The prime advantage of a tandem-twin two-stroke is that the engine can be very narrow while allowing chain final drive without a power-wasting 90° turn. </p><p>Between 1975 and 1982, Kawasaki used the design to win four 250 cc and four 350 cc world championships before they retired from Grand Prix racing.<sup id="cite_ref-17" class="reference"><a href="#cite_note-17"><span class="cite-bracket">[</span>17<span class="cite-bracket">]</span></a></sup> The engine design was also used for a road legal production motorcycle inspired by the racer.<sup id="cite_ref-FOOTNOTEAnderson198430_18-0" class="reference"><a href="#cite_note-FOOTNOTEAnderson198430-18"><span class="cite-bracket">[</span>18<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-19" class="reference"><a href="#cite_note-19"><span class="cite-bracket">[</span>19<span class="cite-bracket">]</span></a></sup> The Kawasaki KR models were instrumental in establishing the company as a manufacturer of high-performance motorcycles.<sup id="cite_ref-FOOTNOTEWalker2003130_20-0" class="reference"><a href="#cite_note-FOOTNOTEWalker2003130-20"><span class="cite-bracket">[</span>20<span class="cite-bracket">]</span></a></sup> </p><p><a href="/wiki/Rotax" title="Rotax">Rotax</a> developed a similar tandem twin design, the model 256, which it sold to independent constructors. The <a href="/wiki/Armstrong-CCM_Motorcycles" title="Armstrong-CCM Motorcycles">CCM Armstrong</a> 250 cc, Waddon, <a href="/wiki/EMC_Motorcycles" title="EMC Motorcycles">EMC</a>, Hejira, Decorite, and Cotton racers used this engine. CCM Armstrong developed a 350 cc version of the engine.<sup id="cite_ref-21" class="reference"><a href="#cite_note-21"><span class="cite-bracket">[</span>21<span class="cite-bracket">]</span></a></sup> <a href="/wiki/Aprilia" title="Aprilia">Aprilia</a>'s 1985 GP racing bikes also used the Rotax model 256.<sup id="cite_ref-Walker_22-0" class="reference"><a href="#cite_note-Walker-22"><span class="cite-bracket">[</span>22<span class="cite-bracket">]</span></a></sup> </p> <div style="clear:both;" class=""></div> <div class="mw-heading mw-heading3"><h3 id="Single_crankshaft">Single crankshaft</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=U_engine&action=edit&section=7" title="Edit section: Single crankshaft"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>An unusual variation on the U engine is the use of a single crankshaft which is linked to the pistons in both cylinder banks by rocking beams. This system was used in an eight-cylinder petrol engine produced by the <a href="/wiki/All-British" class="mw-redirect" title="All-British">All-British</a> Car Company between 1906 and 1908.<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. (April 2021)">citation needed</span></a></i>]</sup> </p> <div class="mw-heading mw-heading2"><h2 id="See_also">See also</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=U_engine&action=edit&section=8" title="Edit section: See also"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><a href="/wiki/Split-single_engine" title="Split-single engine">Split-single engine</a></li> <li><a href="/wiki/List_of_motorcycles_by_type_of_engine" title="List of motorcycles by type of engine">List of motorcycles by type of engine</a></li></ul> <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=U_engine&action=edit&section=9" title="Edit section: References"><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-columns references-column-width" style="column-width: 30em;"> <ol class="references"> <li id="cite_note-L’Ebe-1"><span class="mw-cite-backlink"><b><a href="#cite_ref-L’Ebe_1-0">^</a></b></span> <span class="reference-text">L’Ebé Bugatti, 1966, 'The Bugatti Story', Editions de la Table Ronde & L'Action Automobile, first British edition 1967, <a href="/wiki/Len_Ortzen" title="Len Ortzen">Len Ortzen</a> (translator) and Souvenir Press Ltd, London, pps 70–72, p162</span> </li> <li id="cite_note-racer-2"><span class="mw-cite-backlink"><b><a href="#cite_ref-racer_2-0">^</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 class="citation web cs1"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20111221082439/http://museum.eaa.org/collection/aircraft/Bugatti%20Model%20100%20Racer.asp">"Bugatti Model 100 Racer"</a>. Museum.eaa.org. 1947-08-21. Archived from <a rel="nofollow" class="external text" href="http://museum.eaa.org/collection/aircraft/Bugatti%20Model%20100%20Racer.asp">the original</a> on 2011-12-21<span class="reference-accessdate">. Retrieved <span class="nowrap">2011-12-06</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Bugatti+Model+100+Racer&rft.pub=Museum.eaa.org&rft.date=1947-08-21&rft_id=http%3A%2F%2Fmuseum.eaa.org%2Fcollection%2Faircraft%2FBugatti%2520Model%2520100%2520Racer.asp&rfr_id=info%3Asid%2Fen.wikipedia.org%3AU+engine" 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.bugattirevue.com/revue3/rev3-3.htm#2breguet">"Bugatti License Aircraft Engines"</a>. the Bugatti revue<span class="reference-accessdate">. Retrieved <span class="nowrap">2011-12-06</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Bugatti+License+Aircraft+Engines&rft.pub=the+Bugatti+revue&rft_id=http%3A%2F%2Fwww.bugattirevue.com%2Frevue3%2Frev3-3.htm%232breguet&rfr_id=info%3Asid%2Fen.wikipedia.org%3AU+engine" class="Z3988"></span></span> </li> <li id="cite_note-Ludvigsen-4"><span class="mw-cite-backlink">^ <a href="#cite_ref-Ludvigsen_4-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-Ludvigsen_4-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="Ludvigsen,_V12_Engine" class="citation book cs1"><a href="/wiki/Karl_Ludvigsen" title="Karl Ludvigsen">Ludvigsen, Karl</a> (2005). <i>The V12 Engine</i>. Sparkford, Yeovil: Haynes Publishing. pp. 70–73. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-1-84425-004-2" title="Special:BookSources/978-1-84425-004-2"><bdi>978-1-84425-004-2</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=The+V12+Engine&rft.place=Sparkford%2C+Yeovil&rft.pages=70-73&rft.pub=Haynes+Publishing&rft.date=2005&rft.isbn=978-1-84425-004-2&rft.aulast=Ludvigsen&rft.aufirst=Karl&rfr_id=info%3Asid%2Fen.wikipedia.org%3AU+engine" class="Z3988"></span></span> </li> <li id="cite_note-Fornaca,_1929-5"><span class="mw-cite-backlink"><b><a href="#cite_ref-Fornaca,_1929_5-0">^</a></b></span> <span class="reference-text"><style data-mw-deduplicate="TemplateStyles:r1041539562">.mw-parser-output .citation{word-wrap:break-word}.mw-parser-output .citation:target{background-color:rgba(0,127,255,0.133)}</style><span class="citation patent" id="CITEREFGuido_Fornaca1929"><a rel="nofollow" class="external text" href="https://worldwide.espacenet.com/textdoc?DB=EPODOC&IDX=US1711882">US 1711882</a>, Guido Fornaca, "Internal-Combustion Engine", published 7 May 1929</span><span class="Z3988" title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Apatent&rft.number=1711882&rft.cc=US&rft.title=Internal-Combustion+Engine&rft.inventor=Guido+Fornaca&rft.appldate=26 November 1927&rft.pubdate=7 May 1929"><span style="display: none;"> </span></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="https://www.velocetoday.com/fiat-en-grand-prix-1920-1930/">"Book Review: Fiat en Grand Prix, 1920–1930"</a>. <i>www.velocetoday.com</i><span class="reference-accessdate">. Retrieved <span class="nowrap">11 November</span> 2019</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=www.velocetoday.com&rft.atitle=Book+Review%3A+Fiat+en+Grand+Prix%2C+1920%E2%80%931930&rft_id=https%3A%2F%2Fwww.velocetoday.com%2Ffiat-en-grand-prix-1920-1930%2F&rfr_id=info%3Asid%2Fen.wikipedia.org%3AU+engine" 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="https://motor-car.net/fiat/item/21645-fiat-806">"Fiat 806 GP (1927)"</a>. <i>www.motor-car.net</i><span class="reference-accessdate">. Retrieved <span class="nowrap">11 November</span> 2019</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=www.motor-car.net&rft.atitle=Fiat+806+GP+%281927%29&rft_id=https%3A%2F%2Fmotor-car.net%2Ffiat%2Fitem%2F21645-fiat-806&rfr_id=info%3Asid%2Fen.wikipedia.org%3AU+engine" 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="http://www.derbysulzers.com/sulzerengine.html">"The Sulzer engine in diesel traction: A potted and incomplete history, 1912 – 1990"</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=The+Sulzer+engine+in+diesel+traction%3A+A+potted+and+incomplete+history%2C+1912+%E2%80%93+1990&rft_id=http%3A%2F%2Fwww.derbysulzers.com%2Fsulzerengine.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3AU+engine" 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">Ware, P., 2012, 'Sherman Tank 1941 onwards (all M4 variants); Owner’s Workshop Manual', Haynes Publishing, Yeovil, Somerset, BA227JJ, <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-0-85733-101-4" title="Special:BookSources/978-0-85733-101-4">978-0-85733-101-4</a></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"><a rel="nofollow" class="external free" href="http://www.propulsionplant.ru/content/50/dvigateli/dizelnye-dvigateli/proizvodstvennoe-obedinenie-russkii-dizel/dizeli-tipa-dpn232h30-i-drpn232h30.html">http://www.propulsionplant.ru/content/50/dvigateli/dizelnye-dvigateli/proizvodstvennoe-obedinenie-russkii-dizel/dizeli-tipa-dpn232h30-i-drpn232h30.html</a> <sup class="noprint Inline-Template"><span style="white-space: nowrap;">[<i><a href="/wiki/Wikipedia:Link_rot" title="Wikipedia:Link rot"><span title=" Dead link tagged February 2022">dead link</span></a></i><span style="visibility:hidden; color:transparent; padding-left:2px">‍</span>]</span></sup></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://knowledgeglue.com/was-the-m4-sherman-really-that-bad-a-soviet-perspective/">"Was the M4 Sherman really that bad? A Soviet perspective"</a>. <i>www.knowledgeglue.com</i>. 21 August 2016<span class="reference-accessdate">. Retrieved <span class="nowrap">11 November</span> 2019</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=www.knowledgeglue.com&rft.atitle=Was+the+M4+Sherman+really+that+bad%3F+A+Soviet+perspective&rft.date=2016-08-21&rft_id=http%3A%2F%2Fknowledgeglue.com%2Fwas-the-m4-sherman-really-that-bad-a-soviet-perspective%2F&rfr_id=info%3Asid%2Fen.wikipedia.org%3AU+engine" 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">Cycle World, Volume 46. CBS Publications, 2007</span> </li> <li id="cite_note-13"><span class="mw-cite-backlink"><b><a href="#cite_ref-13">^</a></b></span> <span class="reference-text"><a rel="nofollow" class="external text" href="http://www.brceng.com/pdfs/BRC250FE_Tech_Data_Sept05.pdf">BRC250FE Tech Data Sept 05</a></span> </li> <li id="cite_note-14"><span class="mw-cite-backlink"><b><a href="#cite_ref-14">^</a></b></span> <span class="reference-text">Transactions of the International Engineering Congress, 1916</span> </li> <li id="cite_note-15"><span class="mw-cite-backlink"><b><a href="#cite_ref-15">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFAnderson1984" class="citation journal cs1">Anderson, Steve (November 1984). Dean, Paul (ed.). <a rel="nofollow" class="external text" href="https://books.google.com/books?id=MvO5RoR1buMC&pg=PARA10-PA30">"The Bikes of Japan"</a>. <i><a href="/wiki/Cycle_World" title="Cycle World">Cycle World</a></i>. <b>23</b> (11). Newport Beach, CA US: CBS Magazines: 30. <a href="/wiki/ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/0011-4286">0011-4286</a><span class="reference-accessdate">. Retrieved <span class="nowrap">15 May</span> 2015</span>. <q>Both have at their heart a twin-cylinder two-stroke engine that is, in effect, two 125cc Singles mounted one behind the other in a common crankcase, their cranks connected by large gears.</q></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Cycle+World&rft.atitle=The+Bikes+of+Japan&rft.volume=23&rft.issue=11&rft.pages=30&rft.date=1984-11&rft.issn=0011-4286&rft.aulast=Anderson&rft.aufirst=Steve&rft_id=https%3A%2F%2Fbooks.google.com%2Fbooks%3Fid%3DMvO5RoR1buMC%26pg%3DPARA10-PA30&rfr_id=info%3Asid%2Fen.wikipedia.org%3AU+engine" class="Z3988"></span></span> </li> <li id="cite_note-16"><span class="mw-cite-backlink"><b><a href="#cite_ref-16">^</a></b></span> <span class="reference-text">Top Dead Center 2: Racing and Wrenching With Cycle World's Kevin Cameron. Kevin Cameron, Erik Buell. MBI Publishing Company, 12 Nov 2009</span> </li> <li id="cite_note-17"><span class="mw-cite-backlink"><b><a href="#cite_ref-17">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFWalker2002" class="citation book cs1"><a href="/wiki/Mick_Walker_(motorcycling)" title="Mick Walker (motorcycling)">Walker, Mick</a> (Nov 1, 2002). <a rel="nofollow" class="external text" href="https://books.google.com/books?id=fpoF0PMZEjEC&q=Marco+Lucchinelli&pg=PA78">"5: Kawasaki"</a>. <i>Mick Walker's Japanese Grand Prix Racing Motorcycles</i>. Redline Books. pp. 91–97, 100. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/0-9531-3118-1" title="Special:BookSources/0-9531-3118-1"><bdi>0-9531-3118-1</bdi></a>. <q>Sato, like Kaaden, realised that the convention twin-cylinder two-stroke, with its cylinders across the frame, coupled to the outward facing carburettors of a disc-valve twin had a major drawback, because of excessive width.</q></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=bookitem&rft.atitle=5%3A+Kawasaki&rft.btitle=Mick+Walker%27s+Japanese+Grand+Prix+Racing+Motorcycles&rft.pages=91-97%2C+100&rft.pub=Redline+Books&rft.date=2002-11-01&rft.isbn=0-9531-3118-1&rft.aulast=Walker&rft.aufirst=Mick&rft_id=https%3A%2F%2Fbooks.google.com%2Fbooks%3Fid%3DfpoF0PMZEjEC%26q%3DMarco%2BLucchinelli%26pg%3DPA78&rfr_id=info%3Asid%2Fen.wikipedia.org%3AU+engine" class="Z3988"></span></span> </li> <li id="cite_note-FOOTNOTEAnderson198430-18"><span class="mw-cite-backlink"><b><a href="#cite_ref-FOOTNOTEAnderson198430_18-0">^</a></b></span> <span class="reference-text"><a href="#CITEREFAnderson1984">Anderson 1984</a>, p. 30.</span> </li> <li id="cite_note-19"><span class="mw-cite-backlink"><b><a href="#cite_ref-19">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFWalker2003" class="citation book cs1"><a href="/wiki/Mick_Walker_(motorcycling)" title="Mick Walker (motorcycling)">Walker, Mick</a> (2003). <a rel="nofollow" class="external text" href="https://books.google.com/books?id=TB2v4CR7K4kC"><i>Japanese Production Racing Motorcycles</i></a>. Low Fell, Tyne & Wear, UK: Redline Books. p. 152. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/0954435702" title="Special:BookSources/0954435702"><bdi>0954435702</bdi></a><span class="reference-accessdate">. Retrieved <span class="nowrap">15 May</span> 2015</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Japanese+Production+Racing+Motorcycles&rft.place=Low+Fell%2C+Tyne+%26+Wear%2C+UK&rft.pages=152&rft.pub=Redline+Books&rft.date=2003&rft.isbn=0954435702&rft.aulast=Walker&rft.aufirst=Mick&rft_id=https%3A%2F%2Fbooks.google.com%2Fbooks%3Fid%3DTB2v4CR7K4kC&rfr_id=info%3Asid%2Fen.wikipedia.org%3AU+engine" class="Z3988"></span></span> </li> <li id="cite_note-FOOTNOTEWalker2003130-20"><span class="mw-cite-backlink"><b><a href="#cite_ref-FOOTNOTEWalker2003130_20-0">^</a></b></span> <span class="reference-text"><a href="#CITEREFWalker2003">Walker 2003</a>, p. 130.</span> </li> <li id="cite_note-21"><span class="mw-cite-backlink"><b><a href="#cite_ref-21">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFWalker2000" class="citation book cs1"><a href="/wiki/Mick_Walker_(motorcycling)" title="Mick Walker (motorcycling)">Walker, Mick</a> (May 29, 2000). "Austria". <i>Mick Walker's European Racing Motorcycles</i>. Redline Books. pp. 25–27, Rotax 256 inline twin. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/0-9531-3113-0" title="Special:BookSources/0-9531-3113-0"><bdi>0-9531-3113-0</bdi></a>. <q>These hopes were due to the introduction of the Model 256 inline twin...</q></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=bookitem&rft.atitle=Austria&rft.btitle=Mick+Walker%27s+European+Racing+Motorcycles&rft.pages=25-27%2C+Rotax+256+inline+twin&rft.pub=Redline+Books&rft.date=2000-05-29&rft.isbn=0-9531-3113-0&rft.aulast=Walker&rft.aufirst=Mick&rfr_id=info%3Asid%2Fen.wikipedia.org%3AU+engine" class="Z3988"></span></span> </li> <li id="cite_note-Walker-22"><span class="mw-cite-backlink"><b><a href="#cite_ref-Walker_22-0">^</a></b></span> <span class="reference-text"><a rel="nofollow" class="external text" href="https://books.google.com/books?id=CNsRN9L5BYsC&dq=%22inline-twin%22&pg=PA1978">Italian Racing Motorcycles</a>. Mick Walker. Redline Books, 1 Jan 2000</span> </li> </ol></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:U_engines" class="extiw" title="commons:Category:U engines">U 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="Engine_configurations_for_piston_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"><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:Piston_engine_configurations" title="Template:Piston engine configurations"><abbr title="View this template">v</abbr></a></li><li class="nv-talk"><a href="/wiki/Template_talk:Piston_engine_configurations" title="Template talk:Piston engine configurations"><abbr title="Discuss this template">t</abbr></a></li><li class="nv-edit"><a href="/wiki/Special:EditPage/Template:Piston_engine_configurations" title="Special:EditPage/Template:Piston engine configurations"><abbr title="Edit this template">e</abbr></a></li></ul></div><div id="Engine_configurations_for_piston_engines" style="font-size:114%;margin:0 4em"><a href="/wiki/Engine_configuration" title="Engine configuration">Engine configurations</a> for <a href="/wiki/Piston_engine" class="mw-redirect" title="Piston engine">piston engines</a></div></th></tr><tr><th scope="row" class="navbox-group" style="width:1%">Type</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/Newcomen_atmospheric_engine" title="Newcomen atmospheric engine">Atmospheric</a></li> <li><a href="/wiki/Axial_engine" title="Axial engine">Axial</a></li> <li><a href="/wiki/Beam_engine" title="Beam engine">Beam</a> <ul><li><a href="/wiki/Cornish_steam_engine" class="mw-redirect" title="Cornish steam engine">Cornish</a></li> <li><a href="/wiki/Rotative_beam_engine" class="mw-redirect" title="Rotative beam engine">Rotative</a></li></ul></li> <li><a href="/wiki/Bourke_engine" title="Bourke engine">Bourke</a></li> <li><a href="/wiki/Cam_engine" title="Cam engine">Cam engine</a></li> <li><a href="/wiki/Camless_piston_engine" title="Camless piston engine">Camless</a></li> <li><a href="/wiki/Compound_steam_engine" title="Compound steam engine">Compound</a></li> <li><a href="/wiki/Double-acting_cylinder" class="mw-redirect" title="Double-acting cylinder">Double-acting cylinder</a></li> <li><a href="/wiki/Flathead_engine" title="Flathead engine">Flathead</a></li> <li><a href="/wiki/Free-piston_engine" title="Free-piston engine">Free-piston</a> <ul><li><a href="/wiki/Stelzer_engine" title="Stelzer engine">Stelzer</a></li></ul></li> <li><a href="/wiki/Hemi_engine" class="mw-redirect" title="Hemi engine">Hemi</a></li> <li><a href="/wiki/Heron_cylinder_head" title="Heron cylinder head">Heron head</a></li> <li><a href="/wiki/IOE_engine" title="IOE engine">Intake over exhaust</a></li> <li><a href="/wiki/Oscillating_cylinder_steam_engine" title="Oscillating cylinder steam engine">Oscillating cylinder</a></li> <li><a href="/wiki/Opposed-piston_engine" title="Opposed-piston engine">Opposed-piston</a></li> <li><a href="/wiki/Overhead_camshaft_engine" title="Overhead camshaft engine">Overhead camshaft</a></li> <li><a href="/wiki/Overhead_valve_engine" title="Overhead valve engine">Overhead valve</a></li> <li><a href="/wiki/Pent-roof_combustion_chamber" title="Pent-roof combustion chamber">Pentroof</a></li> <li><a href="/wiki/Rotary_engine" title="Rotary engine">Rotary</a></li> <li><a href="/wiki/Single-acting_cylinder" class="mw-redirect" title="Single-acting cylinder">Single-acting cylinder</a></li> <li><a href="/wiki/Split_cycle_engine" class="mw-redirect" title="Split cycle engine">Split cycle</a></li> <li><a href="/wiki/Swing-piston_engine" title="Swing-piston engine">Swing-piston</a></li> <li><a href="/wiki/Uniflow_steam_engine" title="Uniflow steam engine">Uniflow</a></li> <li><a href="/wiki/Watt_steam_engine" title="Watt steam engine">Watt</a></li> <li><a href="/wiki/Chrysler_wedge_engine" class="mw-redirect" title="Chrysler wedge engine">Wedge</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Stroke_(engine)" title="Stroke (engine)">Stroke cycles</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/Two-stroke_engine" title="Two-stroke engine">Two-stroke</a></li> <li><a href="/wiki/Four-stroke_engine" title="Four-stroke engine">Four-stroke</a></li> <li><a href="/wiki/Five-stroke_engine" title="Five-stroke engine">Five-stroke</a></li> <li><a href="/wiki/Six-stroke_engine" title="Six-stroke engine">Six-stroke</a></li> <li><a href="/wiki/Two-_and_four-stroke_engines" title="Two- and four-stroke engines">Two-and four-stroke</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Engine_configuration" title="Engine configuration">Cylinder layouts</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:10em"><a href="/wiki/Straight_engine" title="Straight engine">Inline / straight</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Single-cylinder_engine" title="Single-cylinder engine">I1</a></li> <li><a href="/wiki/Straight-twin_engine" title="Straight-twin engine">I2</a></li> <li><a href="/wiki/Straight-three_engine" title="Straight-three engine">I3</a></li> <li><a href="/wiki/Straight-four_engine" title="Straight-four engine">I4</a></li> <li><a href="/wiki/Straight-five_engine" title="Straight-five engine">I5</a></li> <li><a href="/wiki/Straight-six_engine" title="Straight-six engine">I6</a></li> <li><a href="/wiki/Straight-seven_engine" title="Straight-seven engine">I7</a></li> <li><a href="/wiki/Straight-eight_engine" title="Straight-eight engine">I8</a></li> <li><a href="/wiki/Straight-nine_engine" title="Straight-nine engine">I9</a></li> <li><a href="/wiki/Straight-twelve_engine" title="Straight-twelve engine">I12</a></li> <li><a href="/wiki/Straight-fourteen_engine" title="Straight-fourteen engine">I14</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:10em"><a href="/wiki/Flat_engine" title="Flat engine">Flat / boxer</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Flat-twin_engine" title="Flat-twin engine">F2</a></li> <li><a href="/wiki/Flat-four_engine" title="Flat-four engine">F4</a></li> <li><a href="/wiki/Flat-six_engine" title="Flat-six engine">F6</a></li> <li><a href="/wiki/Flat-eight_engine" title="Flat-eight engine">F8</a></li> <li><a href="/wiki/Flat-ten_engine" title="Flat-ten engine">F10</a></li> <li><a href="/wiki/Flat-twelve_engine" title="Flat-twelve engine">F12</a></li> <li><a href="/wiki/Flat-sixteen_engine" title="Flat-sixteen engine">F16</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:10em"><a href="/wiki/V_engine" title="V engine">V / Vee</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/V-twin_engine" title="V-twin engine">V2</a></li> <li><a href="/wiki/V3_engine" title="V3 engine">V3</a></li> <li><a href="/wiki/V4_engine" title="V4 engine">V4</a></li> <li><a href="/wiki/V5_engine" title="V5 engine">V5</a> <ul><li><a href="/wiki/VR5_engine" title="VR5 engine">VR5</a></li></ul></li> <li><a href="/wiki/V6_engine" title="V6 engine">V6</a> <ul><li><a href="/wiki/VR6_engine" title="VR6 engine">VR6</a></li></ul></li> <li><a href="/wiki/V8_engine" title="V8 engine">V8</a></li> <li><a href="/wiki/V10_engine" title="V10 engine">V10</a></li> <li><a href="/wiki/V12_engine" title="V12 engine">V12</a></li> <li><a href="/wiki/V14_engine" title="V14 engine">V14</a></li> <li><a href="/wiki/V16_engine" title="V16 engine">V16</a></li> <li><a href="/wiki/V18_engine" title="V18 engine">V18</a></li> <li><a href="/wiki/V20_engine" title="V20 engine">V20</a></li> <li><a href="/wiki/V24_engine" title="V24 engine">V24</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:10em"><a href="/wiki/W_engine" title="W engine">W</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/W_engine#W3_engines" title="W engine">W3</a></li> <li><a href="/wiki/W_engine#W6_engines" title="W engine">W6</a></li> <li><a href="/wiki/W8_engine" title="W8 engine">W8</a></li> <li><a href="/wiki/W12_engine" title="W12 engine">W12</a></li> <li><a href="/wiki/W16_engine" title="W16 engine">W16</a></li> <li><a href="/wiki/W18_engine" title="W18 engine">W18</a></li> <li><a href="/wiki/W_engine#W24_engine" title="W engine">W24</a></li> <li><a href="/wiki/W_engine#W30_engine" title="W engine">W30</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:10em">Other</th><td class="navbox-list-with-group navbox-list navbox-odd" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Napier_Deltic" title="Napier Deltic">Deltic</a></li> <li><a href="/wiki/H_engine" title="H engine">H</a></li> <li><a href="/wiki/Radial_engine" title="Radial engine">Radial</a></li> <li><a href="/wiki/Split-single_engine" title="Split-single engine">Split-single</a></li> <li><a class="mw-selflink selflink">U</a></li> <li><a href="/wiki/X_engine" title="X engine">X</a></li></ul> </div></td></tr></tbody></table><div></div></td></tr></tbody></table></div>    </div><noscript><img src="https://login.wikimedia.org/wiki/Special:CentralAutoLogin/start?type=1x1" 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=U_engine&oldid=1259241374">https://en.wikipedia.org/w/index.php?title=U_engine&oldid=1259241374</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:Piston_engine_configurations" title="Category:Piston engine configurations">Piston engine configurations</a></li><li><a href="/wiki/Category:U_engines" title="Category:U engines">U engines</a></li><li><a href="/wiki/Category:Engines_by_cylinder_layout" title="Category:Engines by cylinder layout">Engines by cylinder layout</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_dead_external_links" title="Category:All articles with dead external links">All articles with dead external links</a></li><li><a href="/wiki/Category:Articles_with_dead_external_links_from_February_2022" title="Category:Articles with dead external links from February 2022">Articles with dead external links from February 2022</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_December_2023" title="Category:Articles needing additional references from December 2023">Articles needing additional references from December 2023</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: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_December_2023" title="Category:Articles with unsourced statements from December 2023">Articles with unsourced statements from December 2023</a></li><li><a href="/wiki/Category:Articles_with_unsourced_statements_from_April_2021" title="Category:Articles with unsourced statements from April 2021">Articles with unsourced statements from April 2021</a></li><li><a href="/wiki/Category:Commons_category_link_is_on_Wikidata" title="Category:Commons category link is on Wikidata">Commons category link is on Wikidata</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 24 November 2024, at 03:45<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=U_engine&mobileaction=toggle_view_mobile" 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-5cd4cd96d5-z48rr","wgBackendResponseTime":132,"wgPageParseReport":{"limitreport":{"cputime":"0.575","walltime":"0.750","ppvisitednodes":{"value":2737,"limit":1000000},"postexpandincludesize":{"value":61355,"limit":2097152},"templateargumentsize":{"value":4142,"limit":2097152},"expansiondepth":{"value":17,"limit":100},"expensivefunctioncount":{"value":5,"limit":500},"unstrip-depth":{"value":1,"limit":20},"unstrip-size":{"value":59893,"limit":5000000},"entityaccesscount":{"value":1,"limit":400},"timingprofile":["100.00% 678.828 1 -total"," 32.41% 220.040 1 Template:Reflist"," 16.49% 111.905 6 Template:Cite_web"," 13.30% 90.318 1 Template:Piston_engine_configurations"," 13.15% 89.274 2 Template:Navbox"," 11.87% 80.560 1 Template:Commons_category"," 11.68% 79.268 1 Template:Short_description"," 11.51% 78.134 1 Template:Sister_project"," 11.23% 76.221 1 Template:Side_box"," 10.80% 73.330 1 Template:Unreferenced_section"]},"scribunto":{"limitreport-timeusage":{"value":"0.365","limit":"10.000"},"limitreport-memusage":{"value":9211569,"limit":52428800},"limitreport-logs":"anchor_id_list = table#1 {\n [\"CITEREFAnderson1984\"] = 1,\n [\"CITEREFGuido_Fornaca1929\"] = 1,\n [\"CITEREFWalker2000\"] = 1,\n [\"CITEREFWalker2002\"] = 1,\n [\"CITEREFWalker2003\"] = 1,\n [\"Ludvigsen,_V12_Engine\"] = 1,\n}\ntemplate_list = table#1 {\n [\"Citation needed\"] = 1,\n [\"Cite book\"] = 4,\n [\"Cite journal\"] = 1,\n [\"Cite patent\"] = 1,\n [\"Cite web\"] = 6,\n [\"Clear\"] = 1,\n [\"Cn\"] = 2,\n [\"Commons category\"] = 1,\n [\"Convert\"] = 3,\n [\"Dead link\"] = 1,\n [\"Google books\"] = 2,\n [\"ISBN\"] = 1,\n [\"Multiple image\"] = 1,\n [\"Piston engine configurations\"] = 1,\n [\"Reflist\"] = 1,\n [\"Sfn\"] = 2,\n [\"Short description\"] = 1,\n [\"Unreferenced section\"] = 1,\n}\narticle_whitelist = table#1 {\n}\n"},"cachereport":{"origin":"mw-web.codfw.main-6b7f745dd4-nxdbf","timestamp":"20241125140014","ttl":2592000,"transientcontent":false}}});});</script> <script type="application/ld+json">{"@context":"https:\/\/schema.org","@type":"Article","name":"U engine","url":"https:\/\/en.wikipedia.org\/wiki\/U_engine","sameAs":"http:\/\/www.wikidata.org\/entity\/Q1536514","mainEntity":"http:\/\/www.wikidata.org\/entity\/Q1536514","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":"2004-08-04T18:35:10Z","dateModified":"2024-11-24T03:45:53Z","image":"https:\/\/upload.wikimedia.org\/wikipedia\/commons\/2\/2b\/U-Engine.gif","headline":"inline engine with two parallel banks driving separate crankshafts"}</script> </body> </html>