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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.


(ˌpri ɪgˈnɪʃ ən)

ignition of the charge in an internal-combustion engine earlier in the cycle than is compatible with proper operation.


[ˌpriːɪgˈnɪʃən] Npreignición f
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.
The same signal can also be used to detect preignition, since an early heat release results in a flame-ionization before the spark [19].
Heated intake temperature conditions were often limited in their maximum intake pressures due to the occurrence of surface preignition on the long-reach spark plug.
The results indicated the control strategy realizes stable and robust control behavior with respect to abnormal combustion conditions, such as preignition [12].
If CR10 and CR17b have the same maximum cylinder pressure, the engine can run with a significantly higher compression ratio for certain loads/speeds without hotspots occurring before combustion that can cause preignition and nonuniform combustion resulting in knock.
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.