- The ignition of the fuel-air charge prior to the spark plug firing. Preignition caused by some other ignition source such as an overheated spark plug tip, carbon deposits in the combustion chamber, and, rarely, a burned exhaust valve. All act as a glow plug to ignite the charge. Preignition occurs during the compression stroke, and the engine continues to fire with the ignition system switched off, although probably not all its cylinders. There is no explosion as in a detonation and the rise of temperature and pressure is much greater, probably resulting in catastrophic consequences. Preignition is often experienced when attempting to start a hot engine or during an attempt to shut down a hot engine, and it usually results in a backfire through the intake manifold.
Aviation dictionary. 2014.
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Preignition — Pre ig*ni tion, n. (Engin.) Ignition in an internal combustion engine while the inlet valve is open or before compression is completed. [Webster 1913 Suppl.] … The Collaborative International Dictionary of English
preignition — [prē΄ig nish′ən] n. in an internal combustion engine, ignition occurring before the intake valve is closed or before the spark plug fires … English World dictionary
preignition — noun Date: 1898 ignition in an internal combustion engine while the inlet valve is open or before compression is completed … New Collegiate Dictionary
preignition — /pree ig nish euhn/, n. ignition of the charge in an internal combustion engine earlier in the cycle than is compatible with proper operation. [1895 1900; PRE + IGNITION] * * * … Universalium
preignition — noun The premature detonation of a charge in . It is sometimes referred to as knocking … Wiktionary
preignition — prÉªËÉªg nÉªÊƒn n. act of lighting in advance, act of kindling ahead of time, act of setting aflame in advance … English contemporary dictionary
preignition — pre·ignition … English syllables
preignition — pre•ig•ni•tion [[t]ˌpri ɪgˈnɪʃ ən[/t]] n. aum ignition of the charge in an internal combustion engine earlier in the cycle than is compatible with proper operation • Etymology: 1895–1900 … From formal English to slang
preignition — The fuel charge being ignited before the proper time. Sometimes causes pinging or detonation. This is the combustion of the fuel air mixture that is not a result of the spark plug s firing, but by high pressure, a flame, or a hot surface … Dictionary of automotive terms
preignition — |prē+ noun Etymology: pre + ignition : ignition in an internal combustion engine occurring while the inlet valve is open or before compression is completed compare autoignition … Useful english dictionary