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class="vector-toc-text"> <span class="vector-toc-numb">2</span> <span>Advantages</span> </div> </a> <ul id="toc-Advantages-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Disadvantages" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Disadvantages"> <div class="vector-toc-text"> <span class="vector-toc-numb">3</span> <span>Disadvantages</span> </div> </a> <ul id="toc-Disadvantages-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-History_and_applications" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#History_and_applications"> <div class="vector-toc-text"> <span class="vector-toc-numb">4</span> <span>History and applications</span> </div> </a> <button aria-controls="toc-History_and_applications-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 and applications subsection</span> </button> <ul id="toc-History_and_applications-sublist" class="vector-toc-list"> <li id="toc-Flathead_cars" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Flathead_cars"> <div class="vector-toc-text"> <span class="vector-toc-numb">4.1</span> <span>Flathead cars</span> </div> </a> <ul id="toc-Flathead_cars-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Flathead_aero-engines" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Flathead_aero-engines"> <div class="vector-toc-text"> <span class="vector-toc-numb">4.2</span> <span>Flathead aero-engines</span> </div> </a> <ul id="toc-Flathead_aero-engines-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Flathead_motorcycles" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Flathead_motorcycles"> <div class="vector-toc-text"> <span class="vector-toc-numb">4.3</span> <span>Flathead motorcycles</span> </div> </a> <ul id="toc-Flathead_motorcycles-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">5</span> <span>See also</span> </div> </a> <ul id="toc-See_also-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Notes" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Notes"> <div class="vector-toc-text"> <span class="vector-toc-numb">6</span> <span>Notes</span> </div> </a> <ul id="toc-Notes-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-External_links" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#External_links"> <div class="vector-toc-text"> <span class="vector-toc-numb">7</span> <span>External links</span> </div> </a> <ul id="toc-External_links-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">Flathead 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 17 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-17" 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">17 languages</span> </label> <div class="vector-dropdown-content"> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li class="interlanguage-link interwiki-ca mw-list-item"><a href="https://ca.wikipedia.org/wiki/Motor_SV" title="Motor SV – Catalan" lang="ca" hreflang="ca" data-title="Motor SV" data-language-autonym="Català" data-language-local-name="Catalan" class="interlanguage-link-target"><span>Català</span></a></li><li class="interlanguage-link interwiki-cs mw-list-item"><a href="https://cs.wikipedia.org/wiki/Side_Valves" title="Side Valves – Czech" lang="cs" hreflang="cs" data-title="Side Valves" 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/SV-Ventilsteuerung" title="SV-Ventilsteuerung – German" lang="de" hreflang="de" data-title="SV-Ventilsteuerung" 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_SV" title="Motor SV – Spanish" lang="es" hreflang="es" data-title="Motor SV" data-language-autonym="Español" data-language-local-name="Spanish" class="interlanguage-link-target"><span>Español</span></a></li><li class="interlanguage-link interwiki-fa mw-list-item"><a href="https://fa.wikipedia.org/wiki/%D9%85%D9%88%D8%AA%D9%88%D8%B1_%D8%B3%D8%B1_%D8%AA%D8%AE%D8%AA" title="موتور سر تخت – Persian" lang="fa" hreflang="fa" data-title="موتور سر تخت" data-language-autonym="فارسی" data-language-local-name="Persian" class="interlanguage-link-target"><span>فارسی</span></a></li><li class="interlanguage-link interwiki-fr mw-list-item"><a href="https://fr.wikipedia.org/wiki/Moteur_%C3%A0_soupapes_lat%C3%A9rales" title="Moteur à soupapes latérales – French" lang="fr" hreflang="fr" data-title="Moteur à soupapes latérales" data-language-autonym="Français" data-language-local-name="French" class="interlanguage-link-target"><span>Français</span></a></li><li class="interlanguage-link interwiki-id mw-list-item"><a href="https://id.wikipedia.org/wiki/Mesin_kepala_datar" title="Mesin kepala datar – Indonesian" lang="id" hreflang="id" data-title="Mesin kepala datar" data-language-autonym="Bahasa Indonesia" data-language-local-name="Indonesian" class="interlanguage-link-target"><span>Bahasa Indonesia</span></a></li><li class="interlanguage-link interwiki-it mw-list-item"><a href="https://it.wikipedia.org/wiki/Valvole_laterali" title="Valvole laterali – Italian" lang="it" hreflang="it" data-title="Valvole laterali" 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/Zijklepmotor" title="Zijklepmotor – Dutch" lang="nl" hreflang="nl" data-title="Zijklepmotor" data-language-autonym="Nederlands" data-language-local-name="Dutch" class="interlanguage-link-target"><span>Nederlands</span></a></li><li class="interlanguage-link interwiki-ja mw-list-item"><a href="https://ja.wikipedia.org/wiki/%E3%82%B5%E3%82%A4%E3%83%89%E3%83%90%E3%83%AB%E3%83%96" title="サイドバルブ – Japanese" lang="ja" hreflang="ja" data-title="サイドバルブ" 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-pl mw-list-item"><a href="https://pl.wikipedia.org/wiki/Silnik_dolnozaworowy" title="Silnik dolnozaworowy – Polish" lang="pl" hreflang="pl" data-title="Silnik dolnozaworowy" data-language-autonym="Polski" data-language-local-name="Polish" class="interlanguage-link-target"><span>Polski</span></a></li><li class="interlanguage-link interwiki-pt mw-list-item"><a href="https://pt.wikipedia.org/wiki/Motor_de_v%C3%A1lvulas_laterais" title="Motor de válvulas laterais – Portuguese" lang="pt" hreflang="pt" data-title="Motor de válvulas laterais" data-language-autonym="Português" data-language-local-name="Portuguese" class="interlanguage-link-target"><span>Português</span></a></li><li class="interlanguage-link interwiki-sco mw-list-item"><a href="https://sco.wikipedia.org/wiki/Side-valve_ingine" title="Side-valve ingine – Scots" lang="sco" hreflang="sco" data-title="Side-valve ingine" data-language-autonym="Scots" data-language-local-name="Scots" class="interlanguage-link-target"><span>Scots</span></a></li><li class="interlanguage-link interwiki-fi mw-list-item"><a href="https://fi.wikipedia.org/wiki/Sivuventtiilimoottori" title="Sivuventtiilimoottori – Finnish" lang="fi" hreflang="fi" data-title="Sivuventtiilimoottori" data-language-autonym="Suomi" data-language-local-name="Finnish" class="interlanguage-link-target"><span>Suomi</span></a></li><li class="interlanguage-link interwiki-sv mw-list-item"><a href="https://sv.wikipedia.org/wiki/Sidventilsmotor" title="Sidventilsmotor – Swedish" lang="sv" hreflang="sv" data-title="Sidventilsmotor" 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/%D0%94%D0%B2%D0%B8%D0%B3%D1%83%D0%BD_%D0%B7_%D0%BF%D0%BB%D0%BE%D1%81%D0%BA%D0%BE%D1%8E_%D0%B3%D0%BE%D0%BB%D0%BE%D0%B2%D0%BA%D0%BE%D1%8E_(Flathead)" title="Двигун з плоскою головкою (Flathead) – Ukrainian" lang="uk" hreflang="uk" data-title="Двигун з плоскою головкою (Flathead)" data-language-autonym="Українська" data-language-local-name="Ukrainian" class="interlanguage-link-target"><span>Українська</span></a></li><li class="interlanguage-link interwiki-vi mw-list-item"><a href="https://vi.wikipedia.org/wiki/C%C6%A1_c%E1%BA%A5u_ph%E1%BB%91i_kh%C3%AD_xupap_%C4%91%E1%BA%B7t" title="Cơ cấu phối khí xupap đặt – Vietnamese" lang="vi" hreflang="vi" data-title="Cơ cấu phối khí xupap đặt" data-language-autonym="Tiếng Việt" data-language-local-name="Vietnamese" class="interlanguage-link-target"><span>Tiếng Việt</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/Q1928719#sitelinks-wikipedia" title="Edit interlanguage links" class="wbc-editpage">Edit links</a></span></div> </div> </div> </div> </header> <div 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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">A type of four-stroke engine</div> <p class="mw-empty-elt"> </p> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:Single-cylinder_T-head_engine_(Autocar_Handbook,_13th_ed,_1935).jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/e/e3/Single-cylinder_T-head_engine_%28Autocar_Handbook%2C_13th_ed%2C_1935%29.jpg/220px-Single-cylinder_T-head_engine_%28Autocar_Handbook%2C_13th_ed%2C_1935%29.jpg" decoding="async" width="220" height="209" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/e/e3/Single-cylinder_T-head_engine_%28Autocar_Handbook%2C_13th_ed%2C_1935%29.jpg/330px-Single-cylinder_T-head_engine_%28Autocar_Handbook%2C_13th_ed%2C_1935%29.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/e/e3/Single-cylinder_T-head_engine_%28Autocar_Handbook%2C_13th_ed%2C_1935%29.jpg/440px-Single-cylinder_T-head_engine_%28Autocar_Handbook%2C_13th_ed%2C_1935%29.jpg 2x" data-file-width="1164" data-file-height="1106" /></a><figcaption>A crossflow T-head sidevalve engine</figcaption></figure> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:Side-valve_engine_v2.png" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/e/ed/Side-valve_engine_v2.png/220px-Side-valve_engine_v2.png" decoding="async" width="220" height="249" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/e/ed/Side-valve_engine_v2.png/330px-Side-valve_engine_v2.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/e/ed/Side-valve_engine_v2.png/440px-Side-valve_engine_v2.png 2x" data-file-width="1088" data-file-height="1230" /></a><figcaption>The usual L-head arrangement</figcaption></figure> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:Side-valve_engine_v3.png" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/5/54/Side-valve_engine_v3.png/220px-Side-valve_engine_v3.png" decoding="async" width="220" height="249" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/5/54/Side-valve_engine_v3.png/330px-Side-valve_engine_v3.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/5/54/Side-valve_engine_v3.png/440px-Side-valve_engine_v3.png 2x" data-file-width="1088" data-file-height="1230" /></a><figcaption>Pop-up pistons may be used to increase compression ratio</figcaption></figure> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:Side-valve_engine_with_Ricardo%27s_turbulent_head_01.png" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/5/52/Side-valve_engine_with_Ricardo%27s_turbulent_head_01.png/220px-Side-valve_engine_with_Ricardo%27s_turbulent_head_01.png" decoding="async" width="220" height="285" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/5/52/Side-valve_engine_with_Ricardo%27s_turbulent_head_01.png/330px-Side-valve_engine_with_Ricardo%27s_turbulent_head_01.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/5/52/Side-valve_engine_with_Ricardo%27s_turbulent_head_01.png/440px-Side-valve_engine_with_Ricardo%27s_turbulent_head_01.png 2x" data-file-width="2218" data-file-height="2876" /></a><figcaption>Flathead with Ricardo's turbulent head</figcaption></figure> <p>A <b>flathead engine</b>, also known as a <b>sidevalve engine</b><sup id="cite_ref-AmericanRodder1994_1-0" class="reference"><a href="#cite_note-AmericanRodder1994-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-2" class="reference"><a href="#cite_note-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup> or <b>valve-in-block engine</b>, is an <a href="/wiki/Internal_combustion_engine" title="Internal combustion engine">internal combustion engine</a> with its <a href="/wiki/Poppet_valve" title="Poppet valve">poppet valves</a> contained within the <a href="/wiki/Cam-in-block" title="Cam-in-block">engine block</a>, instead of in the <a href="/wiki/Cylinder_head" title="Cylinder head">cylinder head</a>, as in an <a href="/wiki/Overhead_valve_engine" title="Overhead valve engine">overhead valve engine</a>. </p><p>Flatheads were widely used internationally by automobile manufacturers from the late 1890s until the mid-1960s<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> but were replaced by more efficient overhead valve and <a href="/wiki/Overhead_camshaft_engine" title="Overhead camshaft engine">overhead camshaft engines</a>. They are currently experiencing a revival in low-revving <a href="/wiki/Aviation_engine" class="mw-redirect" title="Aviation engine">aero-engines</a> such as the <a href="/wiki/D-Motor" title="D-Motor">D-Motor</a>.<sup id="cite_ref-4" class="reference"><a href="#cite_note-4"><span class="cite-bracket">[</span>4<span class="cite-bracket">]</span></a></sup> </p> <meta property="mw:PageProp/toc" /> <div class="mw-heading mw-heading2"><h2 id="The_side-valve_design">The side-valve design</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Flathead_engine&action=edit&section=1" title="Edit section: The side-valve design"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>The valve gear comprises a camshaft sited low in the cylinder block which operates the <a href="/wiki/Poppet_valve" title="Poppet valve">poppet</a> <a href="/wiki/Valves" class="mw-redirect" title="Valves">valves</a> via <a href="/wiki/Tappet" title="Tappet">tappets</a> and short pushrods (or sometimes with no pushrods at all). The flathead system obviates the need for further <a href="/wiki/Valvetrain" title="Valvetrain">valvetrain</a> components such as lengthy pushrods, rocker arms, overhead valves or <a href="/wiki/Overhead_camshaft" class="mw-redirect" title="Overhead camshaft">overhead camshafts</a>.<sup id="cite_ref-5" class="reference"><a href="#cite_note-5"><span class="cite-bracket">[</span>5<span class="cite-bracket">]</span></a></sup> The sidevalves are typically adjacent, sited on one side of the cylinder(s), though some flatheads employ the less common <a href="/wiki/Crossflow_cylinder_head" title="Crossflow cylinder head">"crossflow"</a> <a href="/wiki/T-head_engine" title="T-head engine">"T-head"</a> variant. In a T-head engine, the exhaust gases leave on the opposite side of the cylinder from the intake valve. </p><p>The sidevalve engine's combustion chamber is not above the piston (as in an OHV (overhead valve) engine) but to the side, above the valves. The spark plug may be sited over the piston (as in an OHV engine) or above the valves; but aircraft designs with <a href="/wiki/Dual_ignition" title="Dual ignition">two plugs per cylinder</a> may use either or both positions.<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> </p><p>"Pop-up pistons" may be used with compatible heads to increase compression ratio and improve the combustion chamber's shape to prevent <a href="/wiki/Engine_knocking" title="Engine knocking">knocking</a>.<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> "Pop-up" pistons are so called because, at <a href="/wiki/Top_dead_centre" class="mw-redirect" title="Top dead centre">top dead centre</a>, they protrude above the top of the cylinder block. </p> <div class="mw-heading mw-heading2"><h2 id="Advantages">Advantages</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Flathead_engine&action=edit&section=2" title="Edit section: Advantages"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>The advantages of a sidevalve engine include: simplicity, reliability, low part count, low cost, low weight, compactness, responsive low-speed power, low mechanical engine noise, and insensitivity to low-octane fuel. The absence of a complicated valvetrain allows a compact engine that is cheap to manufacture, since the cylinder head may be little more than a simple metal casting. These advantages explain why side valve engines were used for <a href="/wiki/Car" title="Car">passenger cars</a> for many years, while <a href="/wiki/Overhead_valve_engine" title="Overhead valve engine">OHV</a> designs came to be specified only for high-performance applications such as <a href="/wiki/Aircraft" title="Aircraft">aircraft</a>, <a href="/wiki/Luxury_car" title="Luxury car">luxury cars</a>, <a href="/wiki/Sports_car" title="Sports car">sports cars</a>, and some <a href="/wiki/Sport_motorcycle" class="mw-redirect" title="Sport motorcycle">motorcycles</a>.<sup class="noprint Inline-Template Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources. (October 2021)">citation needed</span></a></i>]</sup> </p><p>At top dead centre, the piston gets very close to the flat portion of the cylinder head above, and the resultant <a href="/wiki/Squish_(piston_engine)" title="Squish (piston engine)">squish</a> <a href="/wiki/Turbulence" title="Turbulence">turbulence</a> produces excellent fuel/air mixing. A feature of the sidevalve design (particularly beneficial for an aero-engine) is that if a valve should seize in its guide and remain partially open, the piston would not be damaged, and the engine would continue operating safely on its other cylinders.<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. (October 2021)">citation needed</span></a></i>]</sup> </p> <div class="mw-heading mw-heading2"><h2 id="Disadvantages">Disadvantages</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Flathead_engine&action=edit&section=3" title="Edit section: Disadvantages"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>The main disadvantages of a sidevalve engine are poor gas flow, poor combustion chamber shape, and low compression ratio, all of which result in a low-revving engine with low power output<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> and low efficiency.<sup id="cite_ref-Kremser_1942_50_9-0" class="reference"><a href="#cite_note-Kremser_1942_50-9"><span class="cite-bracket">[</span>9<span class="cite-bracket">]</span></a></sup> Because sidevalve engines do not burn the fuel efficiently, they suffer from high hydrocarbon emissions.<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> </p><p>Sidevalve engines can only be used for engines operating on the <a href="/wiki/Otto_cycle" title="Otto cycle">Otto principle</a>. The combustion chamber shape is unsuitable for <a href="/wiki/Diesel_engine" title="Diesel engine">Diesel engines</a>,<sup id="cite_ref-Pischinger_1948_14_11-0" class="reference"><a href="#cite_note-Pischinger_1948_14-11"><span class="cite-bracket">[</span>11<span class="cite-bracket">]</span></a></sup> which require a high <a href="/wiki/Compression_ratio" title="Compression ratio">compression ratio</a> for <a href="/wiki/Combustion" title="Combustion">ignition</a> to occur. </p><p>In a sidevalve engine, intake and exhaust gases follow a circuitous route, with low volumetric efficiency, or "poor breathing", not least because the exhaust gases interfere with the incoming charge. Because the exhaust follows a lengthy path to leave the engine, there is a tendency for the engine to <a href="/wiki/Thermal_shock" title="Thermal shock">overheat</a>. (Note: this is true for V-type flathead engines but less of an issue for inline engines which typically have the intake and exhaust ports on the same side of the engine block.) Although a sidevalve engine can safely operate at high speed, its <a href="/wiki/Volumetric_efficiency#Internal_combustion_engines" title="Volumetric efficiency">volumetric efficiency</a> swiftly deteriorates, so that high power outputs are not feasible at speed. High volumetric efficiency was less important for early cars because their engines rarely sustained extended high speeds, but designers seeking higher power outputs had to abandon the sidevalve. A compromise used by the <a href="/wiki/Willys_MB" title="Willys MB">Willys Jeep</a>, <a href="/wiki/Rover_Company" title="Rover Company">Rover</a>, <a href="/wiki/Land_Rover" title="Land Rover">Land Rover</a>, and <a href="/wiki/Rolls-Royce_Limited" title="Rolls-Royce Limited">Rolls-Royce</a> in the 1950s was the <a href="/wiki/F-head_engine" class="mw-redirect" title="F-head engine">"F-head"</a> (or "intake-over-exhaust" valving), which has one sidevalve and one overhead valve per cylinder.<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> </p><p>The flathead's elongated combustion chamber is prone to <a href="/wiki/Engine_knocking" title="Engine knocking">preignition</a> (or "knocking") if compression ratio is increased, but improvements such as <a href="/wiki/Laser_ignition" title="Laser ignition">laser ignition</a> or microwave enhanced ignition might help prevent knocking.<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> Turbulence grooves may increase <a href="/wiki/Combustion_chamber#Swirl" title="Combustion chamber">swirl</a> inside the combustion chamber, thus increasing torque, especially at low rpm. Better mixing of the fuel/air charge improves combustion and helps to prevent knocking.<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><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><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> </p><p>An advance in flathead technology resulted from experimentation in the 1920s by <a href="/wiki/Sir_Harry_Ricardo" class="mw-redirect" title="Sir Harry Ricardo">Sir Harry Ricardo</a>, who improved their efficiency after studying the gas-flow characteristics of sidevalve engines.<sup id="cite_ref-18" class="reference"><a href="#cite_note-18"><span class="cite-bracket">[</span>18<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-Kremser_1942_50_9-1" class="reference"><a href="#cite_note-Kremser_1942_50-9"><span class="cite-bracket">[</span>9<span class="cite-bracket">]</span></a></sup><sup class="noprint Inline-Template" style="margin-left:0.1em; white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Please_clarify" title="Wikipedia:Please clarify"><span title="The text near this tag may need clarification or removal of jargon. (April 2018)">clarification needed</span></a></i>]</sup> </p><p>The difficulty in designing a high-compression-ratio flathead means that most tend to be spark-ignition designs, and flathead diesels are virtually unknown. </p> <div class="mw-heading mw-heading2"><h2 id="History_and_applications">History and applications</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Flathead_engine&action=edit&section=4" title="Edit section: History and applications"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>The sidevalve arrangement was especially common in the United States and used for motor vehicle engines, even for engines with high specific power output.<sup id="cite_ref-Pischinger_1948_14_11-1" class="reference"><a href="#cite_note-Pischinger_1948_14-11"><span class="cite-bracket">[</span>11<span class="cite-bracket">]</span></a></sup> Sidevalve designs are still common for many <a href="/wiki/Small_engine" title="Small engine">small</a> <a href="/wiki/Single-cylinder_engine" title="Single-cylinder engine">single-cylinder</a> or <a href="/wiki/Straight-twin_engine" title="Straight-twin engine">twin-cylinder</a> engines, such as <a href="/wiki/Lawnmower" class="mw-redirect" title="Lawnmower">lawnmowers</a>, <a href="/wiki/Cultivator" title="Cultivator">rotavators</a>, <a href="/wiki/Two-wheel_tractor" title="Two-wheel tractor">two-wheel tractors</a> and other <a href="/wiki/Subsistence_agriculture" title="Subsistence agriculture">basic farm machinery</a>.<sup class="noprint Inline-Template Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources. (January 2019)">citation needed</span></a></i>]</sup> </p> <div class="mw-heading mw-heading3"><h3 id="Flathead_cars">Flathead cars</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Flathead_engine&action=edit&section=5" title="Edit section: Flathead cars"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Multicylinder flathead engines were used for cars such as the <a href="/wiki/Ford_Model_T_engine" title="Ford Model T engine">Ford Model T</a> and <a href="/wiki/Ford_Model_A_(1927%E2%80%9331)" class="mw-redirect" title="Ford Model A (1927–31)">Ford Model A</a>, the <a href="/wiki/Ford_flathead_V8_engine" title="Ford flathead V8 engine">Ford flathead V8 engine</a> and the <a href="/wiki/Ford_Sidevalve_engine" title="Ford Sidevalve engine">Ford Sidevalve engine</a>. <a href="/wiki/Cadillac" title="Cadillac">Cadillac</a> produced <a href="/wiki/Cadillac_V16_engine#Series_90" title="Cadillac V16 engine">V-16 flathead engines</a> for their <a href="/wiki/Cadillac_V-16#1938.E2.80.931940" title="Cadillac V-16">Series 90 luxury cars</a> from 1938–1940.<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> <a href="/wiki/Packard" title="Packard">Packard</a> produced flathead inline 8-cylinder engines until 1954. Also in the British <a href="/wiki/Morris_Eight" title="Morris Eight">Morris Eight</a>, and <a href="/wiki/Morris_Minor" title="Morris Minor">Morris Minor</a> series I. </p><p>After <a href="/wiki/WWII" class="mw-redirect" title="WWII">WWII</a>, flathead designs began to be superseded by OHV (overhead valve) designs. Flatheads were no longer common in <a href="/wiki/Automobile" class="mw-redirect" title="Automobile">cars</a>, but they continued in more rudimentary vehicles such as <a href="/wiki/Off-road_vehicles" class="mw-redirect" title="Off-road vehicles">off-road</a> <a href="/wiki/Jeep" title="Jeep">military Jeeps</a>. In US <a href="/wiki/Custom_car" title="Custom car">custom car</a> and <a href="/wiki/Hot_rod" title="Hot rod">hot rod</a> circles, restored examples of early Ford flathead V8s are still seen.<sup id="cite_ref-AmericanRodder1994_1-1" class="reference"><a href="#cite_note-AmericanRodder1994-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-20" class="reference"><a href="#cite_note-20"><span class="cite-bracket">[</span>20<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading3"><h3 id="Flathead_aero-engines">Flathead aero-engines</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Flathead_engine&action=edit&section=6" title="Edit section: Flathead aero-engines"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>The simplicity, lightness, compactness and reliability might seem ideal for an <a href="/wiki/Aircraft_engine" title="Aircraft engine">aero-engine</a>, but because of their low efficiency, early flathead engines were deemed unsuitable. Two notable exceptions were the American <a href="/wiki/Aeronca_E-107" title="Aeronca E-107">Aeronca E-107</a> opposed twin <a href="/wiki/Aero_engine" class="mw-redirect" title="Aero engine">aero engine</a> of 1930 and the <a href="/wiki/Continental_A40" title="Continental A40">Continental A40</a> flat four of 1931, which became one of the most popular light aircraft engines of the 1930s. Two modern flatheads are the Belgian <a href="/wiki/D-Motor" title="D-Motor">D-Motor</a> <a href="/wiki/Flat-four" class="mw-redirect" title="Flat-four">flat-fours</a> and <a href="/wiki/Flat-six" class="mw-redirect" title="Flat-six">flat-sixes</a>.<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> These are extremely <a href="/wiki/Oversquare" class="mw-redirect" title="Oversquare">oversquare</a> and compact aero-engines with direct drive to a propeller.<sup id="cite_ref-22" class="reference"><a href="#cite_note-22"><span class="cite-bracket">[</span>22<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-WDLA15_23-0" class="reference"><a href="#cite_note-WDLA15-23"><span class="cite-bracket">[</span>23<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading3"><h3 id="Flathead_motorcycles">Flathead motorcycles</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Flathead_engine&action=edit&section=7" title="Edit section: Flathead motorcycles"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <style data-mw-deduplicate="TemplateStyles:r1236090951">.mw-parser-output .hatnote{font-style:italic}.mw-parser-output div.hatnote{padding-left:1.6em;margin-bottom:0.5em}.mw-parser-output .hatnote i{font-style:normal}.mw-parser-output .hatnote+link+.hatnote{margin-top:-0.5em}@media print{body.ns-0 .mw-parser-output .hatnote{display:none!important}}</style><div role="note" class="hatnote navigation-not-searchable">Main article: <a href="/wiki/Flathead_motorcycles" title="Flathead motorcycles">Flathead motorcycles</a></div> <p>Flathead designs have been used on a number of early pre-war motorcycles, in particular US V-twins such as <a href="/wiki/Harley-Davidson" title="Harley-Davidson">Harley-Davidson</a> and <a href="/wiki/Indian_Motocycle_Manufacturing_Company" class="mw-redirect" title="Indian Motocycle Manufacturing Company">Indian</a>, some British singles, <a href="/wiki/History_of_BMW_motorcycles" title="History of BMW motorcycles">BMW</a> <a href="/wiki/Flat_twin" class="mw-redirect" title="Flat twin">flat twins</a> and Russian copies thereof.<sup id="cite_ref-24" class="reference"><a href="#cite_note-24"><span class="cite-bracket">[</span>24<span class="cite-bracket">]</span></a></sup> The <a href="/wiki/Cleveland_Motorcycle_Manufacturing_Company" title="Cleveland Motorcycle Manufacturing Company">Cleveland Motorcycle Manufacturing Company</a> produced a T-head four-cylinder in-line motorcycle engine in the 1920s. </p> <ul class="gallery mw-gallery-traditional"> <li class="gallerybox" style="width: 155px"> <div class="thumb" style="width: 150px; height: 150px;"><span typeof="mw:File"><a href="/wiki/File:1915_Cadillac_Model_51_V8_4stroke_engine_photo2.JPG" class="mw-file-description" title="1915 Cadillac flathead engine block"><img alt="1915 Cadillac flathead engine block" src="//upload.wikimedia.org/wikipedia/commons/thumb/b/b2/1915_Cadillac_Model_51_V8_4stroke_engine_photo2.JPG/120px-1915_Cadillac_Model_51_V8_4stroke_engine_photo2.JPG" decoding="async" width="120" height="90" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/b/b2/1915_Cadillac_Model_51_V8_4stroke_engine_photo2.JPG/180px-1915_Cadillac_Model_51_V8_4stroke_engine_photo2.JPG 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/b/b2/1915_Cadillac_Model_51_V8_4stroke_engine_photo2.JPG/240px-1915_Cadillac_Model_51_V8_4stroke_engine_photo2.JPG 2x" data-file-width="3522" data-file-height="2645" /></a></span></div> <div class="gallerytext">1915 Cadillac flathead engine block</div> </li> <li class="gallerybox" style="width: 155px"> <div class="thumb" style="width: 150px; height: 150px;"><span typeof="mw:File"><a href="/wiki/File:Flathead.jpg" class="mw-file-description" title="Harley-Davidson flathead"><img alt="Harley-Davidson flathead" src="//upload.wikimedia.org/wikipedia/commons/thumb/2/23/Flathead.jpg/120px-Flathead.jpg" decoding="async" width="120" height="91" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/2/23/Flathead.jpg/180px-Flathead.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/2/23/Flathead.jpg/240px-Flathead.jpg 2x" data-file-width="609" data-file-height="463" /></a></span></div> <div class="gallerytext">Harley-Davidson flathead</div> </li> <li class="gallerybox" style="width: 155px"> <div class="thumb" style="width: 150px; height: 150px;"><span typeof="mw:File"><a href="/wiki/File:Indian_Chief_Black_Hawk_80_cubic_inch_1950.jpg" class="mw-file-description" title="Indian Chief Black Hawk"><img alt="Indian Chief Black Hawk" src="//upload.wikimedia.org/wikipedia/commons/thumb/8/81/Indian_Chief_Black_Hawk_80_cubic_inch_1950.jpg/120px-Indian_Chief_Black_Hawk_80_cubic_inch_1950.jpg" decoding="async" width="120" height="63" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/8/81/Indian_Chief_Black_Hawk_80_cubic_inch_1950.jpg/180px-Indian_Chief_Black_Hawk_80_cubic_inch_1950.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/8/81/Indian_Chief_Black_Hawk_80_cubic_inch_1950.jpg/240px-Indian_Chief_Black_Hawk_80_cubic_inch_1950.jpg 2x" data-file-width="849" data-file-height="443" /></a></span></div> <div class="gallerytext">Indian Chief Black Hawk</div> </li> <li class="gallerybox" style="width: 155px"> <div class="thumb" style="width: 150px; height: 150px;"><span typeof="mw:File"><a href="/wiki/File:BMW_motorbike_R_12_(aka).jpg" class="mw-file-description" title="BMW R12"><img alt="BMW R12" src="//upload.wikimedia.org/wikipedia/commons/thumb/4/43/BMW_motorbike_R_12_%28aka%29.jpg/120px-BMW_motorbike_R_12_%28aka%29.jpg" decoding="async" width="120" height="77" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/4/43/BMW_motorbike_R_12_%28aka%29.jpg/180px-BMW_motorbike_R_12_%28aka%29.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/4/43/BMW_motorbike_R_12_%28aka%29.jpg/240px-BMW_motorbike_R_12_%28aka%29.jpg 2x" data-file-width="2500" data-file-height="1601" /></a></span></div> <div class="gallerytext">BMW R12</div> </li> <li class="gallerybox" style="width: 155px"> <div class="thumb" style="width: 150px; height: 150px;"><span typeof="mw:File"><a href="/wiki/File:Cleveland_Model_4-45_1927.jpg" class="mw-file-description" title="Cleveland Model 4-45"><img alt="Cleveland Model 4-45" src="//upload.wikimedia.org/wikipedia/commons/thumb/3/33/Cleveland_Model_4-45_1927.jpg/120px-Cleveland_Model_4-45_1927.jpg" decoding="async" width="120" height="90" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/3/33/Cleveland_Model_4-45_1927.jpg/180px-Cleveland_Model_4-45_1927.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/3/33/Cleveland_Model_4-45_1927.jpg/240px-Cleveland_Model_4-45_1927.jpg 2x" data-file-width="640" data-file-height="480" /></a></span></div> <div class="gallerytext">Cleveland Model 4-45</div> </li> </ul> <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=Flathead_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/Heron_cylinder_head" title="Heron cylinder head">Heron Head</a></li></ul> <div class="mw-heading mw-heading2"><h2 id="Notes">Notes</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Flathead_engine&action=edit&section=9" title="Edit section: Notes"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <style data-mw-deduplicate="TemplateStyles:r1239543626">.mw-parser-output .reflist{margin-bottom:0.5em;list-style-type:decimal}@media screen{.mw-parser-output .reflist{font-size:90%}}.mw-parser-output .reflist .references{font-size:100%;margin-bottom:0;list-style-type:inherit}.mw-parser-output .reflist-columns-2{column-width:30em}.mw-parser-output .reflist-columns-3{column-width:25em}.mw-parser-output .reflist-columns{margin-top:0.3em}.mw-parser-output .reflist-columns ol{margin-top:0}.mw-parser-output .reflist-columns li{page-break-inside:avoid;break-inside:avoid-column}.mw-parser-output .reflist-upper-alpha{list-style-type:upper-alpha}.mw-parser-output .reflist-upper-roman{list-style-type:upper-roman}.mw-parser-output .reflist-lower-alpha{list-style-type:lower-alpha}.mw-parser-output .reflist-lower-greek{list-style-type:lower-greek}.mw-parser-output .reflist-lower-roman{list-style-type:lower-roman}</style><div class="reflist"> <div class="mw-references-wrap mw-references-columns"><ol class="references"> <li id="cite_note-AmericanRodder1994-1"><span class="mw-cite-backlink">^ <a href="#cite_ref-AmericanRodder1994_1-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-AmericanRodder1994_1-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text"><i>American Rodder</i>, 6/94, pp.45 & 93.</span> </li> <li id="cite_note-2"><span class="mw-cite-backlink"><b><a href="#cite_ref-2">^</a></b></span> <span class="reference-text">(As the cylinder cross-section has the shape of an inverted L, other names such as "L-block" or "L-head" are also used)</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"><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://www.autoweek.com/car-life/a1713546/what-was-final-year-new-flathead-powered-american-car/">"What Was the Final Year for a New Flathead-Powered American Car?"</a>. 20 December 2018.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=What+Was+the+Final+Year+for+a+New+Flathead-Powered+American+Car%3F&rft.date=2018-12-20&rft_id=https%3A%2F%2Fwww.autoweek.com%2Fcar-life%2Fa1713546%2Fwhat-was-final-year-new-flathead-powered-american-car%2F&rfr_id=info%3Asid%2Fen.wikipedia.org%3AFlathead+engine" class="Z3988"></span></span> </li> <li id="cite_note-4"><span class="mw-cite-backlink"><b><a href="#cite_ref-4">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20180225114628/http://www.lightningautogyro.com/gallery.aspx">"D-Motor image"</a>. Archived from <a rel="nofollow" class="external text" href="http://lightningautogyro.com/gallery.aspx">the original</a> on 25 February 2018<span class="reference-accessdate">. Retrieved <span class="nowrap">29 April</span> 2018</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=D-Motor+image&rft_id=http%3A%2F%2Flightningautogyro.com%2Fgallery.aspx&rfr_id=info%3Asid%2Fen.wikipedia.org%3AFlathead+engine" class="Z3988"></span></span> </li> <li id="cite_note-5"><span class="mw-cite-backlink"><b><a href="#cite_ref-5">^</a></b></span> <span class="reference-text">An exception is the <a href="/wiki/Indian_Motocycle_Manufacturing_Company" class="mw-redirect" title="Indian Motocycle Manufacturing Company">Indian</a> which employs both rocker arms and pushrods to transmit motion from the cam lobes to the valve stems.</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">The D-motor flathead aero-engines have both spark pugs above the valves.</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 id="CITEREFDavis,_Marlan2006" class="citation web cs1">Davis, Marlan (29 September 2006). <a rel="nofollow" class="external text" href="http://www.hotrod.com/techarticles/engine/hdrp_0511_ford_flathead_engine/viewall.html">"Ford Flathead V8 – The Flathead Guide of Death"</a>. <i>Hotrod.com</i>. Hot Rod Magazine. Combustion Chamber<span class="reference-accessdate">. Retrieved <span class="nowrap">8 April</span> 2014</span>. <q>Trying to gain back compression ratio by using popup pistons may improve airflow provided proper attention is paid to the transfer area and overall piston-to-combustion chamber interface. The best balance has been the subject of debate for over 60 years. Currently the most popular approach is running a big popup piston, but with a scallop on the side adjacent to the valves to keep the transfer area clear between the valves and the cylinder bore. Recommended bottom-line street-gas-friendly compression ratios are between 7.5–8:1 on naturally aspirated engines and 6.5–7.0:1 with a blower.</q></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=Hotrod.com&rft.atitle=Ford+Flathead+V8+%E2%80%93+The+Flathead+Guide+of+Death&rft.pages=Combustion+Chamber&rft.date=2006-09-29&rft.au=Davis%2C+Marlan&rft_id=http%3A%2F%2Fwww.hotrod.com%2Ftecharticles%2Fengine%2Fhdrp_0511_ford_flathead_engine%2Fviewall.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3AFlathead+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="https://stevemckelvie.wordpress.com/2012/07/12/a-critique-of-the-flathead-or-side-valve-engine-design/">"A critique of the flathead or side valve engine"</a>. 13 July 2012<span class="reference-accessdate">. Retrieved <span class="nowrap">22 August</span> 2015</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=A+critique+of+the+flathead+or+side+valve+engine&rft.date=2012-07-13&rft_id=https%3A%2F%2Fstevemckelvie.wordpress.com%2F2012%2F07%2F12%2Fa-critique-of-the-flathead-or-side-valve-engine-design%2F&rfr_id=info%3Asid%2Fen.wikipedia.org%3AFlathead+engine" class="Z3988"></span></span> </li> <li id="cite_note-Kremser_1942_50-9"><span class="mw-cite-backlink">^ <a href="#cite_ref-Kremser_1942_50_9-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-Kremser_1942_50_9-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text">H. Kremser (author): Der Aufbau schnellaufender Verbrennungskraftmaschinen, in Hans List (ed): Die Verbrennungskraftmaschine, volume 11, Springer, Wien 1942, <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/978-3-7091-9755-4" title="Special:BookSources/978-3-7091-9755-4">978-3-7091-9755-4</a>, p. 50</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">Richard van Basshuysen, Fred Schäfer: Handbuch Verbrennungsmotor. 8. Auflage, Springer, Wiesbaden 2017, <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/978-3-658-10901-1" title="Special:BookSources/978-3-658-10901-1">978-3-658-10901-1</a>, Chapter 10, p. 534</span> </li> <li id="cite_note-Pischinger_1948_14-11"><span class="mw-cite-backlink">^ <a href="#cite_ref-Pischinger_1948_14_11-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-Pischinger_1948_14_11-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text">Anton Pischinger (author): Die Steuerung der Verbrennungskraftmaschinen, in Hans List (ed): Die Verbrennungskraftmaschine, volume 9, Springer, Wien 1948, <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/978-3-211-80075-1" title="Special:BookSources/978-3-211-80075-1">978-3-211-80075-1</a>, p. 14</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"><i>Road and Track</i>, some time in the 1960s</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"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFIkedaNishiyamaKaneko2009" class="citation conference cs1">Ikeda, Yuji; Nishiyama, Atsushi; Kaneko, Masashi (5–8 January 2009). <a rel="nofollow" class="external text" href="https://web.archive.org/web/20140725103130/http://enu.kz/repository/2009/AIAA-2009-223.pdf"><i>Microwave Enhanced Ignition Process for Fuel Mixture at Elevated Pressure of 1MPa</i></a> <span class="cs1-format">(PDF)</span>. 47th AIAA Aerospace Sciences Meeting Including The New Horizons Forum and Aerospace Exposition. American Institute of Aeronautics and Astronautics. p. 1. Archived from <a rel="nofollow" class="external text" href="http://enu.kz/repository/2009/AIAA-2009-223.pdf">the original</a> <span class="cs1-format">(PDF)</span> on 25 July 2014<span class="reference-accessdate">. Retrieved <span class="nowrap">3 July</span> 2014</span>. <q>With plasma-enhanced combustion, a large flame kernel formed and the flame propagation speed increased. In the single-cylinder engine, the combustion stability improved and the microwave-enhanced ignition increased the lean limit from 19.3 to 24.1.</q></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=conference&rft.btitle=Microwave+Enhanced+Ignition+Process+for+Fuel+Mixture+at+Elevated+Pressure+of+1MPa&rft.pages=1&rft.pub=American+Institute+of+Aeronautics+and+Astronautics&rft.date=2009-01-05%2F2009-01-08&rft.aulast=Ikeda&rft.aufirst=Yuji&rft.au=Nishiyama%2C+Atsushi&rft.au=Kaneko%2C+Masashi&rft_id=http%3A%2F%2Fenu.kz%2Frepository%2F2009%2FAIAA-2009-223.pdf&rfr_id=info%3Asid%2Fen.wikipedia.org%3AFlathead+engine" class="Z3988"></span></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"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFGraeber,_Charles2004" class="citation web cs1">Graeber, Charles (23 September 2004). <a rel="nofollow" class="external text" href="http://www.popsci.com/cars/article/2004-09/obsession-mr-singhs-search-holy-grail?nopaging=1">"Obsession: Mr. Singh's Search for the Holy Grail"</a>. <i>Popular Science</i>. Bonnier<span class="reference-accessdate">. Retrieved <span class="nowrap">3 July</span> 2014</span>. <q>In November 2002 Singh actually received one such permission from a manufacturer to test his modification on its engines. The manufacturer was Briggs and Stratton, and the engines were two 149cc side valves.</q></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=Popular+Science&rft.atitle=Obsession%3A+Mr.+Singh%27s+Search+for+the+Holy+Grail&rft.date=2004-09-23&rft.au=Graeber%2C+Charles&rft_id=http%3A%2F%2Fwww.popsci.com%2Fcars%2Farticle%2F2004-09%2Fobsession-mr-singhs-search-holy-grail%3Fnopaging%3D1&rfr_id=info%3Asid%2Fen.wikipedia.org%3AFlathead+engine" class="Z3988"></span></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="CITEREFPiranguteN.V.Marathe2002" class="citation techreport cs1">Pirangute, V. G.; N.V.Marathe (14 January 2002). <a rel="nofollow" class="external text" href="https://web.archive.org/web/20161007034551/http://pesn.com/2005/10/13/9600187_Design_to_Improve_Turbulence_in_Combustion_Chambers/ARAI_Test_Report.pdf"><i>Full throttle performance</i></a> <span class="cs1-format">(PDF)</span> (Technical report). ARAI. PUS/2407/Garuda/52(d). Archived from <a rel="nofollow" class="external text" href="http://pesn.com/2005/10/13/9600187_Design_to_Improve_Turbulence_in_Combustion_Chambers/ARAI_Test_Report.pdf">the original</a> <span class="cs1-format">(PDF)</span> on 7 October 2016.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=report&rft.btitle=Full+throttle+performance&rft.pub=ARAI&rft.date=2002-01-14&rft.aulast=Pirangute&rft.aufirst=V.+G.&rft.au=N.V.Marathe&rft_id=http%3A%2F%2Fpesn.com%2F2005%2F10%2F13%2F9600187_Design_to_Improve_Turbulence_in_Combustion_Chambers%2FARAI_Test_Report.pdf&rfr_id=info%3Asid%2Fen.wikipedia.org%3AFlathead+engine" class="Z3988"></span> The test report reveals that fuel consumption and temperatures decreased at low engine speed while torque increased.</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"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFamrelweekil2009" class="citation web cs1">amrelweekil (14 September 2009). <a rel="nofollow" class="external text" href="https://www.youtube.com/watch?v=PzMgPZxD7Iw&t=90">"Engine modify by Somender Singh"</a>. <i>YouTube</i>. Grooved flathead at 1:31–1:38. <a rel="nofollow" class="external text" href="https://ghostarchive.org/varchive/youtube/20211212/PzMgPZxD7Iw">Archived</a> from the original on 12 December 2021<span class="reference-accessdate">. Retrieved <span class="nowrap">9 April</span> 2014</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=YouTube&rft.atitle=Engine+modify+by+Somender+Singh&rft.pages=Grooved+flathead+at+1%3A31-1%3A38&rft.date=2009-09-14&rft.au=amrelweekil&rft_id=https%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3DPzMgPZxD7Iw%26t%3D90&rfr_id=info%3Asid%2Fen.wikipedia.org%3AFlathead+engine" class="Z3988"></span></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">Patent <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"><a rel="nofollow" class="external text" href="https://worldwide.espacenet.com/textdoc?DB=EPODOC&IDX=US6237579">US 6237579</a></span><span class="Z3988" title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Apatent&rft.number=6237579&rft.cc=US&rft.title="><span style="display: none;"> </span></span> Somender Singh: "Design to improve turbulence in combustion chambers"</span> </li> <li id="cite_note-18"><span class="mw-cite-backlink"><b><a href="#cite_ref-18">^</a></b></span> <span class="reference-text"><i>The internal-combustion engine</i> by Harry Ralph Ricardo, Blackie and Son Limited.</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="CITEREFLaChance2007" class="citation web cs1">LaChance, David (February 2007). <a rel="nofollow" class="external text" href="http://www.hemmings.com/hcc/stories/2007/02/01/hmn_feature6.html">"Reignmaker – 1939 Cadillac Series 39-90"</a>. <i>Hemmings Motor News</i>. American City Business Journals<span class="reference-accessdate">. Retrieved <span class="nowrap">17 November</span> 2015</span>. <q>Mechanically, the Series 90 cars shared the advances of the Series 75. The V-8 car's three-speed manual transmission was deemed up to the task of handing the torque of the V-16, in part because the larger engine delivered its impulses so smoothly.</q></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=Hemmings+Motor+News&rft.atitle=Reignmaker+%E2%80%93+1939+Cadillac+Series+39-90&rft.date=2007-02&rft.aulast=LaChance&rft.aufirst=David&rft_id=http%3A%2F%2Fwww.hemmings.com%2Fhcc%2Fstories%2F2007%2F02%2F01%2Fhmn_feature6.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3AFlathead+engine" class="Z3988"></span></span> </li> <li id="cite_note-20"><span class="mw-cite-backlink"><b><a href="#cite_ref-20">^</a></b></span> <span class="reference-text"><i>Street Rodder</i>, 1/85, p.72.</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">Although very small and compact, the D-Motor flat-six displaces nearly 4 litres.</span> </li> <li id="cite_note-22"><span class="mw-cite-backlink"><b><a href="#cite_ref-22">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20120328094443/http://d-motor1.vpweb.be/Recent-information.html">"Kapelstraat 198 8540 Deerlijk – Recent information"</a>. D-motor.eu. Archived from <a rel="nofollow" class="external text" href="http://d-motor1.vpweb.be/Recent-information.html">the original</a> on March 28, 2012<span class="reference-accessdate">. Retrieved <span class="nowrap">December 6,</span> 2011</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Kapelstraat+198+8540+Deerlijk+%E2%80%93+Recent+information&rft.pub=D-motor.eu&rft_id=http%3A%2F%2Fd-motor1.vpweb.be%2FRecent-information.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3AFlathead+engine" class="Z3988"></span></span> </li> <li id="cite_note-WDLA15-23"><span class="mw-cite-backlink"><b><a href="#cite_ref-WDLA15_23-0">^</a></b></span> <span class="reference-text">Tacke, Willi; Marino Boric; et al: <i>World Directory of Light Aviation 2015-16</i>, pages 256-257. Flying Pages Europe SARL, 2015. <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><a href="/wiki/ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://www.worldcat.org/search?fq=x0:jrnl&q=n2:1368-485X">1368-485X</a></span> </li> <li id="cite_note-24"><span class="mw-cite-backlink"><b><a href="#cite_ref-24">^</a></b></span> <span class="reference-text">For example, some Dnepr and Ural used flathead designs that BMW had licensed to the Soviets.</span> </li> </ol></div></div> <div class="mw-heading mw-heading2"><h2 id="External_links">External links</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Flathead_engine&action=edit&section=10" title="Edit section: External links"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><a rel="nofollow" class="external text" href="http://www.flatheads-forever.com/">Ford Flathead Engine</a></li> <li><a rel="nofollow" class="external text" href="http://www.factoryfat.com/hdmotorhistory.html">Images of each style of Harley-Davidson engine</a></li> <li><a rel="nofollow" class="external text" href="http://www.harleykmodel.com">Harley-Davidson K-model motorcycles</a></li></ul> <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 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href="/wiki/Convertible" title="Convertible">Cabriolet / Convertible / Drophead coupe</a></li> <li><a href="/wiki/Coupe" title="Coupe">Coupe</a></li> <li><a href="/wiki/Coupe_de_Ville" class="mw-redirect" title="Coupe de Ville">Coupé de Ville / Sedanca de Ville</a></li> <li><a href="/wiki/Coup%C3%A9_utility" title="Coupé utility">Coupé utility</a></li> <li><a href="/wiki/Fastback" title="Fastback">Fastback</a></li> <li><a href="/wiki/Hardtop" title="Hardtop">Hardtop</a></li> <li><a href="/wiki/Hatchback" title="Hatchback">Hatchback</a></li> <li><a href="/wiki/Kammback" title="Kammback">Kammback</a></li> <li><a href="/wiki/Landaulet_(car)" title="Landaulet (car)">Landaulet</a></li> <li><a href="/wiki/Liftback" title="Liftback">Liftback</a></li> <li><a href="/wiki/Limousine" title="Limousine">Limousine</a></li> <li><a href="/wiki/Microvan" title="Microvan">Microvan</a></li> <li><a href="/wiki/Minibus" title="Minibus">Minibus</a></li> <li><a href="/wiki/Multi-stop_truck" title="Multi-stop truck">Multi-stop truck</a></li> <li><a href="/wiki/Notchback" title="Notchback">Notchback</a></li> <li><a href="/wiki/Panel_van" title="Panel van">Panel van</a></li> <li><a href="/wiki/Phaeton_body" title="Phaeton body">Phaeton</a></li> <li><a href="/wiki/Pickup_truck" title="Pickup truck">Pickup truck</a></li> <li><a href="/wiki/Quad_coup%C3%A9" class="mw-redirect" title="Quad coupé">Quad coupé</a></li> <li><a href="/wiki/Convertible" title="Convertible">Retractable hardtop</a></li> <li><a href="/wiki/Roadster_(automobile)" class="mw-redirect" title="Roadster (automobile)">Roadster / Spider / Spyder</a></li> <li><a href="/wiki/Runabout_(car)" title="Runabout (car)">Runabout</a></li> <li><a href="/wiki/Sedan_(automobile)" title="Sedan (automobile)">Saloon / Sedan</a></li> <li><a href="/wiki/Panel_van" title="Panel van">Sedan delivery/Panel van</a></li> <li><a href="/wiki/Shooting_brake" title="Shooting brake">Shooting brake</a></li> <li><a href="/wiki/Station_wagon" title="Station wagon">Station wagon</a></li> <li><a href="/wiki/Targa_top" title="Targa top">Targa top</a></li> <li><a href="/wiki/Torpedo_(car)" title="Torpedo (car)">Torpedo</a></li> <li><a href="/wiki/Touring_car" title="Touring car">Touring</a></li> <li><a href="/wiki/Coupe_de_Ville" class="mw-redirect" title="Coupe de Ville">Town (Coupé de Ville)</a></li> <li><a href="/wiki/T-top" title="T-top">T-top</a></li> <li><a href="/wiki/Vis-%C3%A0-vis_(carriage)" title="Vis-à-vis (carriage)">Vis-à-vis</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Specialized <br />vehicles</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/All-terrain_vehicle" title="All-terrain vehicle">All-terrain vehicle</a></li> <li><a href="/wiki/Amphibious_vehicle" title="Amphibious vehicle">Amphibious</a></li> <li><a href="/wiki/Connected_car" title="Connected car">Connected</a></li> <li><a href="/wiki/Self-driving_car" title="Self-driving car">Driverless (autonomous)</a></li> <li><a href="/wiki/Go-kart" title="Go-kart">Go-kart</a></li> <li><a href="/wiki/Gyrocar" title="Gyrocar">Gyrocar</a></li> <li><a href="/wiki/Quadracycle" title="Quadracycle">Pedal car</a></li> <li><a href="/wiki/Personal_rapid_transit" title="Personal rapid transit">Personal rapid transit</a></li> <li><a href="/wiki/Police_car" title="Police car">Police car</a></li> <li><a href="/wiki/Flying_car" title="Flying car">Flying car</a></li> <li><a href="/wiki/Taxicab" class="mw-redirect" title="Taxicab">Taxicab</a></li> <li><a href="/wiki/Tow_truck" title="Tow truck">Tow truck</a></li> <li><a href="/wiki/Voiturette" title="Voiturette">Voiturette</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Ground_propulsion" title="Ground propulsion">Propulsion</a></th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Alternative_fuel_vehicle" title="Alternative fuel vehicle">Alternative fuel</a></li> <li><a href="/wiki/Autogas" title="Autogas">Autogas</a></li> <li><a href="/wiki/Biodiesel" title="Biodiesel">Biodiesel</a></li> <li><a href="/wiki/Biofuel" title="Biofuel">Biofuel</a></li> <li><a href="/wiki/Biogasoline" title="Biogasoline">Biogasoline</a></li> <li><a href="/wiki/Biogas" title="Biogas">Biogas</a></li> <li><a href="/wiki/Compressed_natural_gas" title="Compressed natural gas">Compressed natural gas</a></li> <li><a href="/wiki/Diesel_engine" title="Diesel engine">Diesel</a></li> <li><a href="/wiki/Electric_vehicle" title="Electric vehicle">Electric</a> (<a href="/wiki/Battery_electric_vehicle" title="Battery electric vehicle">battery</a></li> <li><a href="/wiki/Neighborhood_Electric_Vehicle" title="Neighborhood Electric Vehicle">NEV</a>)</li> <li><a href="/wiki/Common_ethanol_fuel_mixtures" title="Common ethanol fuel mixtures">Ethanol</a> (<a href="/wiki/E85" title="E85">E85</a>)</li> <li><a href="/wiki/Fossil_fuel" title="Fossil fuel">Fossil fuel</a></li> <li><a href="/wiki/Fuel_cell" title="Fuel cell">Fuel cell</a></li> <li><a href="/wiki/Fuel_gas" title="Fuel gas">Fuel gas</a></li> <li><a href="/wiki/Natural_gas" title="Natural gas">Natural gas</a></li> <li><a href="/wiki/Petrol_engine" title="Petrol engine">Gasoline / petrol</a> (<a href="/wiki/Gasoline_direct_injection" title="Gasoline direct injection">direct injection</a>)</li> <li><a href="/wiki/Homogeneous_charge_compression_ignition" title="Homogeneous charge compression ignition">Homogeneous charge compression ignition</a></li> <li><a href="/wiki/Hybrid_electric_vehicle" title="Hybrid electric vehicle">Hybrid</a> (<a href="/wiki/Plug-in_hybrid" title="Plug-in hybrid">plug-in</a>)</li> <li><a href="/wiki/Hydrogen_vehicle" title="Hydrogen vehicle">Hydrogen</a></li> <li><a href="/wiki/Internal_combustion_engine" title="Internal combustion engine">Internal combustion</a></li> <li><a href="/wiki/Liquid_nitrogen_engine" title="Liquid nitrogen engine">Liquid nitrogen</a></li> <li><a href="/wiki/Liquified_petroleum_gas" class="mw-redirect" title="Liquified petroleum gas">Liquified petroleum gas</a></li> <li><a href="/wiki/Steam_car" title="Steam car">Steam</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Drive_wheel" title="Drive wheel">Drive wheels</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/Front-wheel_drive" title="Front-wheel drive">Front-wheel</a></li> <li><a href="/wiki/Powertrain_layout#Rear_wheel_drive_layouts" title="Powertrain layout">Rear-wheel</a></li> <li><a href="/wiki/Two-wheel_drive" title="Two-wheel drive">Two-wheel</a></li> <li><a href="/wiki/Four-wheel_drive" title="Four-wheel drive">Four-wheel</a></li> <li><a href="/wiki/Six-wheel_drive" title="Six-wheel drive">Six-wheel</a></li> <li><a href="/wiki/Eight-wheel_drive" title="Eight-wheel drive">Eight-wheel</a></li> <li><a href="/wiki/Ten-wheel_drive" class="mw-redirect" title="Ten-wheel drive">Ten-wheel</a></li> <li><a href="/wiki/Twelve-wheel_drive" class="mw-redirect" title="Twelve-wheel drive">Twelve-wheel</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Powertrain_layout" title="Powertrain layout">Engine position</a></th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Front-engine_design" title="Front-engine design">Front</a></li> <li><a href="/wiki/Mid-engine_design" title="Mid-engine design">Mid</a></li> <li><a href="/wiki/Rear-engine_design" title="Rear-engine design">Rear</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Powertrain_layout" title="Powertrain layout">Layout</a> <br /><span class="nobold">(engine / drive)</span></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/Front-engine,_front-wheel-drive_layout" title="Front-engine, front-wheel-drive layout">Front-front</a> </li> <li> <a href="/wiki/Front-mid-engine,_front-wheel-drive_layout" title="Front-mid-engine, front-wheel-drive layout">Front mid-front</a> </li> <li> <a href="/wiki/Rear-engine,_front-wheel-drive_layout" title="Rear-engine, front-wheel-drive layout">Rear-front</a> </li> <li> <a href="/wiki/Front-engine,_rear-wheel-drive_layout" title="Front-engine, rear-wheel-drive layout">Front-rear</a> </li> <li> <a href="/wiki/Rear_mid-engine,_rear-wheel-drive_layout" title="Rear mid-engine, rear-wheel-drive layout">Rear mid-rear</a> </li> <li> <a href="/wiki/Rear-engine,_rear-wheel-drive_layout" title="Rear-engine, rear-wheel-drive layout">Rear-rear</a> </li> <li> <a href="/wiki/Front-engine,_four-wheel-drive_layout" title="Front-engine, four-wheel-drive layout">Front-four-wheel</a> </li> <li> <a href="/wiki/Mid-engine,_four-wheel-drive_layout" title="Mid-engine, four-wheel-drive layout">Mid-four-wheel</a> </li> <li> <a href="/wiki/Rear-engine,_four-wheel-drive_layout" title="Rear-engine, four-wheel-drive layout">Rear-four-wheel</a> </li> <li> <a href="/wiki/Dual-motor,_four-wheel-drive_layout" title="Dual-motor, four-wheel-drive layout">Dual motor-four-wheel</a> </li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Engine_configuration" title="Engine configuration">Engine configuration</a><br /><span class="nobold">(<a href="/wiki/Internal_combustion_engine" title="Internal combustion engine">internal combustion</a>)</span></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/Flat_engine" title="Flat engine">Boxer</a></li> <li><a href="/wiki/Flat_engine" title="Flat engine">Flat</a></li> <li><a href="/wiki/Four-stroke_engine" title="Four-stroke engine">Four-stroke</a></li> <li><a href="/wiki/H_engine" title="H engine">H-block</a></li> <li><a href="/wiki/Reciprocating_engine" title="Reciprocating engine">Reciprocating</a></li> <li><a href="/wiki/Single-cylinder_engine" title="Single-cylinder engine">Single-cylinder</a></li> <li><a href="/wiki/Straight_engine" title="Straight engine">Straight</a></li> <li><a href="/wiki/Two-stroke_engine" title="Two-stroke engine">Two-stroke</a></li> <li><a href="/wiki/V_engine" title="V engine">V (Vee)</a></li> <li><a href="/wiki/W_engine" title="W engine">W engine</a></li> <li><a href="/wiki/Wankel_engine" title="Wankel engine">Wankel</a></li></ul> </div></td></tr><tr><td class="navbox-abovebelow hlist" colspan="2" style="font-weight:bold;"><div> <ul><li><a href="/wiki/Portal:Cars" title="Portal:Cars">Portal</a></li> <li><a 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