Definition:
A damaging engine condition wherein the air/fuel mixture ignites spontaneously due to hot spots in the combustion chamber. Causes include engine-overheating, spark plugs that are the wrong heat range (too hot), sharp edges on the combustion chamber, low octane gasoline, a lean fuel mixture, or carbon buildup in the combustion chamber. Preignition can burn holes in pistons and contribute to detonation.
<Back to Last Page> <Full Glossary>
© 2000 - 2002 Vincent T. Ciulla
