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Old 08-22-2011, 07:17 PM   #15 (permalink)
oil pan 4
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Quote:
Originally Posted by Nerys View Post
Hmmm what would cause pre ignition?
In 2007 compiled a list of known causes on my old laptop but dont have it with me.
From what I can remember some of the causes were:
Fuel octane grade too low
Ignition timing too far advanced
engine running too hot
spark plug heat range too hot
Improper air fuel ratio (too lean)
carbon build up in the combustion chamber
poor oil control allowing oil up into the combustion chamber
Excessive exhaust back pressure
Intake air too hot (under hood intake)
Or you are running a less than ideal compression ratio, operating temp and fuel octane setup.

That is about 1/3 of the original list. But most of the others were for high power applications.
Such as when the spark plug arm over heats, turning it into a little glow plug (normally a problem for people who run nitrous).
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