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<title>Engine knocking</title>

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<span id="openzim-page-title" class="mw-page-title-main"><span class="mw-page-title-main">Engine knocking</span></span>

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</style><div role="note" class="hatnote navigation-not-searchable">"Pinging" redirects here. For other uses, see <a href="Ping_(disambiguation)" class="mw-redirect mw-disambig" title="Ping (disambiguation)">Ping (disambiguation)</a>.</div>

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<p>In <a href="Spark-ignition_engine" title="Spark-ignition engine">spark-ignition internal combustion engines</a>, <b>knocking</b> (also <b>knock</b>, <b>detonation</b>, <b>spark knock</b>, <b>pinging</b> or <b>pinking</b>) occurs when combustion of some of the <a href="Air-fuel_ratio" class="mw-redirect" title="Air-fuel ratio">air/fuel mixture</a> in the cylinder does not result from propagation of the flame front ignited by the <a href="Spark_plug" title="Spark plug">spark plug</a>, but when one or more pockets of air/fuel mixture explode outside the envelope of the normal combustion front. The fuel–air charge is meant to be ignited by the spark plug only, and at a precise point in the piston's stroke. Knock occurs when the peak of the combustion process no longer occurs at the optimum moment for the <a href="Four-stroke_cycle" class="mw-redirect" title="Four-stroke cycle">four-stroke cycle</a>. The shock wave creates the characteristic metallic "pinging" sound, and cylinder pressure increases dramatically. Effects of engine knocking range from inconsequential to completely destructive.

</p><p>Knocking should not be confused with <a href="Pre-ignition" title="Pre-ignition">pre-ignition</a>—they are two separate events. However, pre-ignition can be followed by knocking.

</p><p>The phenomenon of detonation was described in November 1914 in a letter from Lodge Brothers (spark plug manufacturers, and sons of Sir <a href="Oliver_Lodge" title="Oliver Lodge">Oliver Lodge</a>) settling a discussion regarding the cause of "knocking" or "pinging" in motorcycles. In the letter they stated that an early ignition can give rise to the gas detonating instead of the usual expansion, and the sound that is produced by the detonation is the same as if the metal parts had been tapped with a hammer.<sup id="cite_ref-1" class="reference"><a href="#cite_note-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup> It was further investigated and described by <a href="Harry_Ricardo" title="Harry Ricardo">Harry Ricardo</a> during experiments carried out between 1916 and 1919 to discover the reason for failures in <a href="Aircraft_engine" title="Aircraft engine">aircraft engines</a>.<sup id="cite_ref-2" class="reference"><a href="#cite_note-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup>

</p>

<div class="mw-heading mw-heading2"><h2 id="Normal_combustion">Normal combustion</h2></div>

<p>Under regular operating conditions, an internal combustion engine burns the air/fuel mixture in the cylinder in an orderly and controlled fashion. The combustion is started by the spark plug some 10 to 40 crankshaft degrees prior to <a href="Top_dead_center" class="mw-redirect" title="Top dead center">top dead center</a> (TDC), depending on many factors including engine speed and <a href="Mechanical_load" title="Mechanical load">load</a>. This ignition advance allows time for the combustion process to develop peak pressure at the ideal time for maximum recovery of work from the expanding gases.<sup id="cite_ref-b2_3-0" class="reference"><a href="#cite_note-b2-3"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup>

</p><p>The spark across the spark plug's electrodes forms a small kernel of flame approximately the size of the spark plug gap. As it grows in size, its heat output increases, which allows it to grow at an accelerating rate, expanding rapidly through the combustion chamber. This growth is due to the travel of the flame front through the combustible fuel–air mix itself, and due to <a href="Rayleigh%E2%80%93Taylor_instability" title="Rayleigh–Taylor instability">Rayleigh–Taylor instability</a> (resulting from the hot, low-density combustion gasses expanding into the relatively cold and dense unburnt fuel–air mix) which rapidly stretches the burning zone into a complex of fingers of burning gas that have a much greater surface area than a simple spherical ball of flame would have (this latter process is enhanced and accelerated by any pre-existing turbulence in the fuel–air mixture). In normal combustion, this flame front moves throughout the air/fuel mixture at a rate characteristic for the particular mixture. Pressure rises smoothly to a peak, as nearly all the available fuel is consumed, then pressure falls as the piston descends. Maximum cylinder pressure is achieved a few crankshaft degrees after the piston passes TDC, so that the force applied on the piston (from the increasing pressure applied to the top surface of the piston) can give its hardest push precisely when the piston's speed and mechanical advantage on the crank shaft gives the best recovery of force from the expanding gases, thus maximizing torque transferred to the crankshaft.<sup id="cite_ref-b2_3-1" class="reference"><a href="#cite_note-b2-3"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-b3_4-0" class="reference"><a href="#cite_note-b3-4"><span class="cite-bracket">[</span>4<span class="cite-bracket">]</span></a></sup>

</p>

<div class="mw-heading mw-heading2"><h2 id="Abnormal_combustion">Abnormal combustion</h2></div>

<div role="note" class="hatnote navigation-not-searchable">Main article: <a href="Cool_flame" title="Cool flame">Cool flame</a></div>

<p>When unburned fuel–air mixture beyond the boundary of the <a href="Flame_front" class="mw-redirect" title="Flame front">flame front</a> is subjected to a combination of heat and pressure for a certain duration (beyond the delay period of the fuel used), <a href="Detonation" title="Detonation">detonation</a> may occur. Detonation is characterized by an almost instantaneous, explosive ignition of at least one pocket of air/fuel mixture outside of the flame front. A local shockwave is created around each pocket, and the cylinder pressure will rise sharply – and possibly beyond its design limits – causing damage. (Detonation is actually more efficient than deflagration, but is usually avoided due to its damaging effects on engine components.)

</p><p>If detonation is allowed to persist under extreme conditions or over many engine cycles, engine parts can be damaged or destroyed. The simplest deleterious effect is particle wear caused by moderate knocking, with the resulting particulate dispersing into the engine's oil system causing abrasive wear on other parts prior to being trapped by the oil filter. Such wear gives the appearance of erosion, abrasion, or a "sandblasted" look, similar to the damage caused by hydraulic <a href="Cavitation" title="Cavitation">cavitation</a>. Severe knocking can lead to catastrophic failure in the form of physical holes melted and pushed through the <a href="Piston" title="Piston">piston</a> or <a href="Cylinder_head" title="Cylinder head">cylinder head</a> (i.e. rupture of the <a href="Combustion_chamber" title="Combustion chamber">combustion chamber</a>), either of which depressurizes the affected cylinder and introduces large metal fragments, fuel, and combustion products into the oil system. <a href="Hypereutectic_piston" title="Hypereutectic piston">Hypereutectic pistons</a> are known to break easily from such shock waves.<sup id="cite_ref-b3_4-1" class="reference"><a href="#cite_note-b3-4"><span class="cite-bracket">[</span>4<span class="cite-bracket">]</span></a></sup>

</p><p>Detonation can be prevented by any or all of the following techniques:

</p>

<ul><li>retarding ignition timing</li>

<li>the use of a fuel with high <a href="Octane_rating" title="Octane rating">octane rating</a>, which increases the combustion temperature of the fuel and reduces the proclivity to detonate</li>

<li>enriching the <a href="Air%E2%80%93fuel_ratio" title="Air–fuel ratio">air–fuel ratio</a> which alters the chemical reactions during combustion, reduces the combustion temperature and increases the margin to detonation</li>

<li>reducing peak cylinder pressure</li>

<li>decreasing the <a href="Manifold_pressure" class="mw-redirect" title="Manifold pressure">manifold pressure</a> by reducing the throttle opening or boost pressure</li>

<li>reducing the load on the engine</li>

<li>addition of a <a href="Antiknock_agent" title="Antiknock agent">knock inhibitor</a> to fuel, increasing the effective octane rating and resistance to detonation</li></ul>

<p>Because pressure and temperature are strongly linked, knock can also be attenuated by controlling peak combustion chamber temperatures by <a href="Compression_ratio" title="Compression ratio">compression ratio</a> reduction, <a href="Exhaust_gas_recirculation" title="Exhaust gas recirculation">exhaust gas recirculation</a>, appropriate calibration of the engine's <a href="Ignition_timing" title="Ignition timing">ignition timing</a> schedule, and careful design of the engine's combustion chambers and cooling system as well as controlling the initial air intake temperature.

</p><p>The addition of <a href="Tetraethyl_lead" class="mw-redirect" title="Tetraethyl lead">tetraethyl lead</a> (TEL), a soluble organolead compound added to gasoline, was common until it was discontinued for reasons of toxic pollution. Lead dust added to the intake charge will also reduce knock with various hydrocarbon fuels. <a href="Manganese" title="Manganese">Manganese</a> compounds are also used to reduce knock with petrol fuel.

</p><p>Knock is less common in cold climates. As an aftermarket solution, a <a href="Water_injection_(engines)" class="mw-redirect" title="Water injection (engines)">water injection</a> system can be employed to reduce combustion chamber peak temperatures and thus suppress detonation. Steam (water vapor) will suppress knock even though no added cooling is supplied.

</p><p>Turbulence, as stated, has a very important effect on knock. Engines with good turbulence tend to knock less than engines with poor turbulence. Turbulence occurs not only while the engine is inhaling but also when the mixture is compressed and burned. Many pistons are designed to use <a href="Squish_(piston_engine)" title="Squish (piston engine)">"squish" turbulence</a> to violently mix the air and fuel together as they are ignited and burned, which reduces knock greatly by speeding up burning and cooling the unburnt mixture. One example of this is all modern side valve or <a href="Flathead_engine" title="Flathead engine">flathead engines</a>. A considerable portion of the head space is made to come in close proximity to the piston crown, making for much turbulence near TDC. In the early days of side valve heads this was not done and a much lower compression ratio had to be used for any given fuel. Also such engines were sensitive to ignition advance and had less power.<sup id="cite_ref-b3_4-2" class="reference"><a href="#cite_note-b3-4"><span class="cite-bracket">[</span>4<span class="cite-bracket">]</span></a></sup>

</p><p>Knocking is more or less unavoidable in <a href="Diesel_engine" title="Diesel engine">diesel engines</a>, where fuel is injected into highly compressed air towards the end of the compression stroke. There is a short lag between the fuel being injected and combustion starting. By this time there is already a quantity of fuel in the combustion chamber which will ignite first in areas of greater oxygen density prior to the combustion of the complete charge. This sudden increase in pressure and temperature causes the distinctive diesel 'knock' or 'clatter', some of which must be allowed for in the engine design.

</p><p>Careful design of the injector pump, fuel injector, combustion chamber, piston crown and cylinder head can reduce knocking greatly, and modern engines using electronic <a href="Common_rail" title="Common rail">common rail</a> injection have very low levels of knock. Engines using <a href="Indirect_injection" title="Indirect injection">indirect injection</a> generally have lower levels of knock than <a href="Fuel_injection#Direct_injection_systems" title="Fuel injection">direct injection</a> engines, due to the greater dispersal of oxygen in the combustion chamber and lower injection pressures providing a more complete mixing of fuel and air. Diesels actually do not suffer exactly the same "knock" as gasoline engines since the cause is known to be only the very fast rate of pressure rise, not unstable combustion. Diesel fuels are actually very prone to knock in gasoline engines but in the diesel engine there is no time for knock to occur because the fuel is only oxidized during the expansion cycle. In the gasoline engine the fuel is slowly oxidizing all the time while it is being compressed before the spark. This allows for changes to occur in the structure/makeup of the molecules before the very critical period of high temperature/pressure.<sup id="cite_ref-b3_4-3" class="reference"><a href="#cite_note-b3-4"><span class="cite-bracket">[</span>4<span class="cite-bracket">]</span></a></sup>

</p>

<div class="mw-heading mw-heading2"><h2 id="Knock_detection">Knock detection</h2></div>

<p>Due to the large variation in fuel quality, atmospheric pressure and ambient temperature as well as the possibility of a malfunction, every modern combustion engine contains mechanisms to detect and prevent knocking.

</p><p>A control loop is permanently monitoring the signal of one or more <b>knock sensors</b> (commonly <a href="Piezoelectric_sensor" title="Piezoelectric sensor">piezoelectric sensor</a> which are able to translate vibrations into an electric signal). If the characteristic pressure peak of a knocking combustion is detected the ignition timing is retarded by steps of a few degrees. If the signal normalizes indicating a controlled combustion the ignition timing is advanced again in the same fashion keeping the engine at its best possible operating point - the so-called ″knock limit″. Modern knock control-loop systems are able to adjust ignition timings for every cylinder individually. Depending on the specific engine the boost pressure is regulated simultaneously. This way performance is kept at its optimum while mostly eliminating the risk of engine damage caused by knock (e.g. when running on low octane fuel).<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> An early example of this is in <a href="Turbocharger" title="Turbocharger">turbocharged</a> <a href="Saab_H_engine" title="Saab H engine">Saab H engines</a>, where a system called <a href="Automatic_Performance_Control" title="Automatic Performance Control">Automatic Performance Control</a> was used to reduce boost pressure if it caused the engine to knock.<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>

<div class="mw-heading mw-heading2"><h2 id="Knock_prediction">Knock prediction</h2></div>

<p>Since the avoidance of knocking combustion is so important to development engineers, a variety of simulation technologies have been developed which can identify engine design or operating conditions in which knock might be expected to occur. This then enables engineers to design ways to mitigate knocking combustion whilst maintaining a high <a href="Thermal_efficiency" title="Thermal efficiency">thermal efficiency</a>.

</p><p>Since the onset of knock is sensitive to the in-cylinder pressure, temperature and autoignition chemistry associated with the local mixture compositions within the combustion chamber, simulations which account for all of these aspects<sup id="cite_ref-Advanced_Simulation_Technologies_7-0" class="reference"><a href="#cite_note-Advanced_Simulation_Technologies-7"><span class="cite-bracket">[</span>7<span class="cite-bracket">]</span></a></sup> have thus proven most effective in determining knock operating limits and enabling engineers to determine the most appropriate operating strategy.

</p>

<div class="mw-heading mw-heading2"><h2 id="Knock_control">Knock control</h2></div>

<p>The objective of knock control strategies is to attempt to optimize the trade-off between protecting the engine from damaging knock events and maximizing the engine's output torque. Knock events are an independent random process.<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> It is impossible to design knock controllers in a deterministic platform. A single time history simulation or experiment of knock control methods are not able to provide a repeatable measurement of controller's performance because of the random nature of arriving knock events. Therefore, the desired trade-off must be done in a <a href="Stochastic" title="Stochastic">stochastic</a> framework which could provide a suitable environment for designing and evaluating different knock control strategies performances with rigorous statistical properties.

</p>

<div class="mw-heading mw-heading2"><h2 id="References">References</h2></div>

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<li id="cite_note-1"><span class="mw-cite-backlink"><b><a href="#cite_ref-1">^</a></b></span> <span class="reference-text">Letter from Lodge Brothers & Co Ltd, The Motor Cycle, 12 November 1914, p. 528</span>

</li>

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</style><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://www.flightglobal.com/pdfarchive/view/1951/1951%20-%202155.html">"Aviation fuels | abadan | world war | 1951 | 2155 | Flight Archive"</a>. <a rel="nofollow" class="external text" href="https://web.archive.org/web/20160318093539/https://www.flightglobal.com/pdfarchive/view/1951/1951%20-%202155.html">Archived</a> from the original on 18 March 2016<span class="reference-accessdate">. Retrieved <span class="nowrap">16 March</span> 2016</span>.</cite></span>

</li>

<li id="cite_note-b2-3"><span class="mw-cite-backlink">^ <a href="#cite_ref-b2_3-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-b2_3-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text"><cite id="CITEREFErjavec2005" class="citation book cs1">Erjavec, Jack (2005). <a rel="nofollow" class="external text" href="https://books.google.com/books?id=U4TBoJB2zgsC&pg=PA630"><i>Automotive technology: a systems approach</i></a>. Cengage Learning. p. 630. <a href="ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <bdi>978-1-4018-4831-6</bdi>.</cite></span>

</li>

<li id="cite_note-b3-4"><span class="mw-cite-backlink">^ <a href="#cite_ref-b3_4-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-b3_4-1"><sup><i><b>b</b></i></sup></a> <a href="#cite_ref-b3_4-2"><sup><i><b>c</b></i></sup></a> <a href="#cite_ref-b3_4-3"><sup><i><b>d</b></i></sup></a></span> <span class="reference-text"><cite id="CITEREFH.N._Gupta2006" class="citation book cs1">H.N. Gupta (2006). <a rel="nofollow" class="external text" href="https://books.google.com/books?id=MFx4VRErHNoC&pg=RA1-PA171"><i>Fundamentals of Internal Combustion Engines</i></a>. PHI Learning. pp. <span class="nowrap">169–</span>173. <a href="ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <bdi>978-81-203-2854-9</bdi>.</cite></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"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://www.europa-lehrmittel.de/t-1/modern_automotive_technology_fundamentals_service_diagnostics-84/">"Modern Automotive Technology - Fundamentals, Service, Diagnostics"</a>. <i>Europa-lehrmittel.de</i>. <a href="Europa-Lehrmittel" title="Europa-Lehrmittel">Europa-Lehrmittel</a>.</cite></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"><cite class="citation magazine cs1"><a rel="nofollow" class="external text" href="https://books.google.com/books?id=q0qVc8dQrpgC&pg=PA85">"Turbocharger with a Brain"</a>. <i>Popular Science</i>. Vol. 221, no. 1. Bonnier. July 1982. p. 85<span class="reference-accessdate">. Retrieved <span class="nowrap">9 December</span> 2023</span>.</cite></span>

</li>

<li id="cite_note-Advanced_Simulation_Technologies-7"><span class="mw-cite-backlink"><b><a href="#cite_ref-Advanced_Simulation_Technologies_7-0">^</a></b></span> <span class="reference-text"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20110409215355/http://www.cmclinnovations.com/products/srmsuite/srmsuite-SI.html">"Advanced simulation technologies"</a>. Cmcl Innovations, UK. Archived from <a rel="nofollow" class="external text" href="http://www.cmclinnovations.com/products/srmsuite/srmsuite-SI.html">the original</a> on 9 April 2011<span class="reference-accessdate">. Retrieved <span class="nowrap">12 June</span> 2010</span>.</cite></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"><cite id="CITEREFJonesFreyShayestehmanesh2017" class="citation journal cs1">Jones, J. C. Peyton; Frey, J.; Shayestehmanesh, S. (July 2017). "Stochastic Simulation and Performance Analysis of Classical Knock Control Algorithms". <i>IEEE Transactions on Control Systems Technology</i>. <b>25</b> (4): <span class="nowrap">1307–</span>1317. <a href="Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1109%2FTCST.2016.2603065">10.1109/TCST.2016.2603065</a>. <a href="ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/1063-6536">1063-6536</a>. <a href="S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:8039910">8039910</a>.</cite></span>

</li>

</ol></div></div>

<div class="mw-heading mw-heading2"><h2 id="Further_reading">Further reading</h2></div>

<ul><li><cite id="CITEREFdi_GaetaGiglioPoliceRispoli2013" class="citation journal cs1">di Gaeta, Alessandro; Giglio, Veniero; Police, Giuseppe; Rispoli, Natale (2013). "Modeling of in-cylinder pressure oscillations under knocking conditions: A general approach based on the damped wave equation". <i>Fuel</i>. <b>104</b>: <span class="nowrap">230–</span>243. <a href="Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/2013Fuel..104..230D">2013Fuel..104..230D</a>. <a href="Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1016%2Fj.fuel.2012.07.066">10.1016/j.fuel.2012.07.066</a>.</cite></li>

<li><cite id="CITEREFGiglioPoliceRispoliIorio2011" class="citation book cs1">Giglio, Veniero; Police, Giuseppe; Rispoli, Natale; Iorio, Biagio; di Gaeta, Alessandro (2011). "Experimental Evaluation of Reduced Kinetic Models for the Simulation of Knock in SI Engines". <i>SAE Technical Paper Series</i>. Vol. 1. <a href="Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.4271%2F2011-24-0033">10.4271/2011-24-0033</a>.</cite></li>

<li><cite id="CITEREFdi_GaetaGiglioPoliceReale2010" class="citation book cs1">di Gaeta, Alessandro; Giglio, Veniero; Police, Giuseppe; Reale, Fabrizio; Rispoli, Natale (2010). "Modeling Pressure Oscillations under Knocking Conditions: A Partial Differential Wave Equation Approach". <i>SAE Technical Paper Series</i>. Vol. 1. <a href="Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.4271%2F2010-01-2185">10.4271/2010-01-2185</a>.</cite></li>

<li><a rel="nofollow" class="external text" href="https://web.archive.org/web/20110220032111/http://www.cmclinnovations.com/userstories/userstory7.html"><i>Predictive combustion simulations for “downsized” direct injection spark-ignition engines: solutions for pre-ignition (“mega-knock”), misfire, extinction, flame propagation and conventional “knock”</i></a>, cmcl innovations, accessed June 2010.</li>

<li><a rel="nofollow" class="external text" href="http://www.streetrodstuff.com/Articles/Engine/Detonation/"><i>Engine Basics: Detonation and Pre-Ignition</i></a>, Allen W. Cline, accessed June 2007.</li>

<li><cite id="CITEREFGiglioPoliceRispolidi_Gaeta2009" class="citation book cs1">Giglio, Veniero; Police, Giuseppe; Rispoli, Natale; di Gaeta, Alessandro; Cecere, Michele; Della Ragione, Livia (2009). "Experimental Investigation on the Use of Ion Current on SI Engines for Knock Detection". <i>SAE Technical Paper Series</i>. Vol. 1. <a href="Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.4271%2F2009-01-2745">10.4271/2009-01-2745</a>.</cite></li>

<li><cite id="CITEREFTaylor1985" class="citation book cs1">Taylor, Charles Fayette (1985). <i>The Internal-combustion Engine in Theory and Practice: Combustion, fuels, materials, design</i>. MIT Press. <a href="ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <bdi>9780262700276</bdi>.</cite></li></ul>

<div class="mw-heading mw-heading2"><h2 id="External_links">External links</h2></div>

<ul><li><a rel="nofollow" class="external text" href="https://web.archive.org/web/20051222155001/http://naca.central.cranfield.ac.uk/reports/1942/naca-report-727.pdf">NACA Report 727 - Combustion and knock in a spark-ignition engine (Archived)</a></li>

<li><a rel="nofollow" class="external text" href="https://archive.org/details/NASA_NTRS_Archive_19930081637/mode/2up">NACA Report 774 - Ionization in the knock zone of an internal combustion engine (Archived)</a></li>

<li><a rel="nofollow" class="external text" href="https://apps.dtic.mil/sti/pdfs/ADA800847.pdf">NACA Report 912 - Interdependence of various types of autoignition and knock (via DTIC)</a></li></ul>

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</style><div id="Internal_combustion_engine562" style="font-size:114%;margin:0 4em"><a href="Internal_combustion_engine" title="Internal combustion engine">Internal combustion engine</a></div></th></tr><tr><td class="navbox-abovebelow" colspan="2"><div><i>Part of the <a href="Car" title="Car">Automobile</a> series</i></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="Engine_block" title="Engine block">Engine block</a> and<br> rotating assembly</th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em">

<ul><li><a href="Balance_shaft" title="Balance shaft">Balance shaft</a></li>

<li><a href="Block_heater" title="Block heater">Block heater</a></li>

<li><a href="Connecting_rod" title="Connecting rod">Connecting rod</a></li>

<li><a href="Crankcase" title="Crankcase">Crankcase</a></li>

<li><a href="Crankcase_ventilation_system" title="Crankcase ventilation system">Crankcase ventilation system (PCV valve)</a></li>

<li><a href="Crankpin" title="Crankpin">Crankpin</a></li>

<li><a href="Crankshaft" title="Crankshaft">Crankshaft</a></li>

<li><a href="Core_plug" title="Core plug">Core plug (freeze plug)</a></li>

<li><a href="Cylinder_(engine)" title="Cylinder (engine)">Cylinder</a> (<a href="Cylinder_bank" class="mw-redirect" title="Cylinder bank">bank</a>, <a href="Engine_configuration" title="Engine configuration">layout</a>)</li>

<li><a href="Engine_displacement" title="Engine displacement">Displacement</a></li>

<li><a href="Flywheel" title="Flywheel">Flywheel</a></li>

<li><a href="Firing_order" title="Firing order">Firing order</a></li>

<li><a href="Stroke_(engine)" title="Stroke (engine)">Stroke</a></li>

<li><a href="Main_bearing" title="Main bearing">Main bearing</a></li>

<li><a href="Piston" title="Piston">Piston</a></li>

<li><a href="Piston_ring" title="Piston ring">Piston ring</a></li>

<li><a href="Starter_ring_gear" title="Starter ring gear">Starter ring gear</a></li></ul>

</div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="Valvetrain" title="Valvetrain">Valvetrain</a> and<br> <a href="Cylinder_head" title="Cylinder head">Cylinder head</a></th><td class="navbox-list-with-group navbox-list navbox-even hlist" style="width:100%;padding:0"><div style="padding:0 0.25em">

<ul><li><a href="Flathead_engine" title="Flathead engine">Flathead layout</a></li>

<li><a href="Overhead_camshaft_engine" title="Overhead camshaft engine">Overhead camshaft layout</a></li>

<li><a href="Overhead_valve_engine" title="Overhead valve engine">Overhead valve (pushrod) layout</a></li></ul>

<ul><li><a href="Tappet" title="Tappet">Tappet / lifter</a></li>

<li><a href="Camshaft" title="Camshaft">Camshaft</a></li>

<li><a href="Chest_(mechanical_engineering)" title="Chest (mechanical engineering)">Chest</a></li>

<li><a href="Combustion_chamber" title="Combustion chamber">Combustion chamber</a></li>

<li><a href="Compression_ratio" title="Compression ratio">Compression ratio</a></li>

<li><a href="Head_gasket" title="Head gasket">Head gasket</a></li>

<li><a href="Rocker_arm" title="Rocker arm">Rocker arm</a></li>

<li><a href="Timing_belt_(camshaft)" title="Timing belt (camshaft)">Timing belt</a></li>

<li><a href="Poppet_valve" title="Poppet valve">Valve</a></li></ul>

</div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="Forced_induction" title="Forced induction">Forced induction</a></th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em">

<ul><li><a href="Blowoff_valve" title="Blowoff valve">Blowoff valve</a></li>

<li><a href="Boost_controller" title="Boost controller">Boost controller</a></li>

<li><a href="Intercooler" title="Intercooler">Intercooler</a></li>

<li><a href="Supercharger" title="Supercharger">Supercharger</a></li>

<li><a href="Turbocharger" title="Turbocharger">Turbocharger</a></li></ul>

</div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Fuel system</th><td class="navbox-list-with-group navbox-list navbox-even hlist" style="width:100%;padding:0"><div style="padding:0 0.25em">

<ul><li><a href="Diesel_engine" title="Diesel engine">Diesel engine</a></li>

<li><a href="Petrol_engine" title="Petrol engine">Petrol engine</a></li>

<li><a href="Carburetor" title="Carburetor">Carburetor</a></li>

<li><a href="Fuel_filter" title="Fuel filter">Fuel filter</a></li>

<li><a href="Fuel_injection" title="Fuel injection">Fuel injection</a></li>

</div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="Ignition_system" title="Ignition system">Ignition</a></th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em">

<ul><li><a href="Ignition_magneto" title="Ignition magneto">Magneto</a></li>

<li><a href="Compression_ignition" class="mw-redirect" title="Compression ignition">Compression ignition</a></li>

<li><a href="Distributor" title="Distributor">Distributor</a></li>

<li><a href="Ignition_coil" title="Ignition coil">Ignition coil</a></li>

<li><a href="Spark_plug" title="Spark plug">Spark plug</a></li>

<li><a href="Spark_plug_wires" title="Spark plug wires">Spark plug wires</a></li></ul>

</div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><div style="display: inline-block; line-height: 1.2em; padding: .1em 0;">Engine management</div></th><td class="navbox-list-with-group navbox-list navbox-even hlist" style="width:100%;padding:0"><div style="padding:0 0.25em">

<ul><li><a href="Engine_control_unit" title="Engine control unit">Engine control unit (ECU)</a></li></ul>

</div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><div style="display: inline-block; line-height: 1.2em; padding: .1em 0;">Electrical system</div></th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em">

<ul><li><a href="Alternator_(automotive)" title="Alternator (automotive)">Alternator</a></li>

<li><a href="Automotive_battery" title="Automotive battery">Battery</a></li>

<li><a href="Dynamo" title="Dynamo">Dynamo</a></li>

<li><a href="Starter_(engine)" title="Starter (engine)">Starter motor</a></li></ul>

</div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Intake system</th><td class="navbox-list-with-group navbox-list navbox-even hlist" style="width:100%;padding:0"><div style="padding:0 0.25em">

<ul><li><a href="Airbox" title="Airbox">Airbox</a></li>

<li><a href="Air_filter#Internal_combustion_engine_air_filters" title="Air filter">Air filter</a></li>

<li><a href="Idle_air_control_actuator" title="Idle air control actuator">Idle air control actuator</a></li>

<li><a href="Inlet_manifold" title="Inlet manifold">Inlet manifold</a></li>

<li><a href="MAP_sensor" title="MAP sensor">MAP sensor</a></li>

<li><a href="Mass_flow_sensor" title="Mass flow sensor">MAF sensor</a></li>

<li><a href="Throttle" title="Throttle">Throttle</a></li>

<li><a href="Throttle_position_sensor" title="Throttle position sensor">Throttle position sensor</a></li></ul>

</div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="Exhaust_system" title="Exhaust system">Exhaust system</a></th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em">

<ul><li><a href="Catalytic_converter" title="Catalytic converter">Catalytic converter</a></li>

<li><a href="Diesel_particulate_filter" title="Diesel particulate filter">Diesel particulate filter</a></li>

<li><a href="Exhaust_gas_temperature_gauge" title="Exhaust gas temperature gauge">EGT sensor</a></li>

<li><a href="Exhaust_manifold" title="Exhaust manifold">Exhaust manifold</a></li>

<li><a href="Muffler" title="Muffler">Muffler</a></li>

<li><a href="Oxygen_sensor#Automotive_applications" title="Oxygen sensor">Oxygen sensor</a></li></ul>

</div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="Internal_combustion_engine_cooling" title="Internal combustion engine cooling">Cooling system</a></th><td class="navbox-list-with-group navbox-list navbox-even hlist" style="width:100%;padding:0"><div style="padding:0 0.25em">

<ul><li><a href="Air_cooling" title="Air cooling">Air cooling</a></li>

<li><a href="Water_cooling" title="Water cooling">Water cooling</a></li></ul>

<ul><li><a href="Fan_(machine)" title="Fan (machine)">Electric fan</a></li>

<li><a href="Radiator_(engine_cooling)" title="Radiator (engine cooling)">Radiator</a></li>

<li><a href="Thermostat" title="Thermostat">Thermostat</a></li>

<li><a href="Fan_clutch" title="Fan clutch">Viscous fan (fan clutch)</a></li></ul>

</div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Lubrication</th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em">

<li><a href="Oil_filter" title="Oil filter">Oil filter</a></li>

</div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Other</th><td class="navbox-list-with-group navbox-list navbox-even hlist" style="width:100%;padding:0"><div style="padding:0 0.25em">

<ul>

<li><a href="Power_band" title="Power band">Power band</a></li>

<li><a href="Redline" title="Redline">Redline</a></li>

<li><a href="Stratified_charge_engine" title="Stratified charge engine">Stratified charge</a></li>

<li><a href="Dead_centre_(engineering)" title="Dead centre (engineering)">Top dead centre</a></li></ul>

</div></td></tr><tr><td class="navbox-abovebelow hlist" colspan="2" style="font-weight:bold;"><div>

<ul><li><a href="Portal%3ACars" title="Portal:Cars">Portal</a></li>

<li>Category</li></ul>

</div></td></tr></tbody></table></div>

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