Also found in: Encyclopedia, Wikipedia.
Related to preignition: Spark knock


The ignition of fuel in an internal-combustion engine before the spark passes through the fuel, resulting from a hot spot in the cylinder or from too great a compression ratio for the fuel.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.


(ˌpri ɪgˈnɪʃ ən)

ignition of the charge in an internal-combustion engine earlier in the cycle than is compatible with proper operation.
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.


[ˌpriːɪgˈnɪʃən] Npreignición f
Collins Spanish Dictionary - Complete and Unabridged 8th Edition 2005 © William Collins Sons & Co. Ltd. 1971, 1988 © HarperCollins Publishers 1992, 1993, 1996, 1997, 2000, 2003, 2005
References in periodicals archive ?
Continuing to allow a malfunctioning mag (or electronic ignition) to run risks the mistimed spark causing preignition and/or detonation, which can cause catastrophic damage to the engine.
For another, during studying the effect of the Al particle size on the thermal degradation of Al-PTFE mixtures, Osborne and Pantoya [21] found that nano-Al-PTFE mixtures had obvious preignition reaction (PIR) phenomenon when heated over 400[degrees]C, which contributes to accelerating the reaction of Al-PTFE.
This easily leads to surface ignition under high temperature, inducing preignition deflagration and some other tough operating conditions of engine, and thereby dramatically increasing the emission amount of N[O.sub.X] and [PM.sub.2.5/10].
The mathematical model can be used to help in the design of a spark ignition engine for alternative fuels as well as to study various problems such as pollutant emissions, engine performance, preignition, knocking and misdistribution of the fuel-air mixture.
A mainstream view is that, in a superknock cycle, the occurrence of preignition is related to the dilution of the cylinder oil which may be caused by spray impingement on cylinder wall for turbocharged GDI engines.
The cylinder head displayed re-solidified, splattered metal around the sparkplug holes, valves, and valve seats, a feature consistent with preignition and/or detonation.
The British engine boffins achieved this transformation by remapping the engine management system to squirt more fuel into the cylinders for preignition. This does mean the engine uses more fuel than its European cousin but we're talking about a teaspoon extra for every couple of thousand miles and, trust me, the trade-off is well worth it.
However systems of this type have not yet been utilized in practice, except that lead tetraethyl has been used to modify the preignition knocking phenomena of internal combustion systems.