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Old 11-10-2019, 06:52 PM   #9
160B
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Join Date: Aug 2010
Location: Port Orchard, WA
Posts: 1,498
Default Re: What spark plugs are you currently using?

Quote:
Originally Posted by rfitzpatrick View Post
What does it mean when you said they're to hot/cold plz. I really don't understand.
Thanks
Spark plug heat range is the measure of how fast the spark plug tip dissipates combustion heat. It must do this in a precise and controlled manner so the spark plug will:
Stay cool enough to avoid pre-ignition and/or electrode destruction due to detonation.
Run hot enough to burn off combustion deposits that would otherwise collect on the sparkplug insulator tip and cause fouling, that leads to misfire.
Adapt to specific engine characteristics and widely varying driving/load conditions.

"Hot" spark plugs remove heat from the combustion area relatively slowly. They have a longer insulator tip and they achieve a temperature higher than the deposition zone relatively fast.
"Cold" spark plugs feature a relatively short insulator tip and they remove heat from the combustion area quite fast, in order to avoid advanced ignitions.
The choice of a proper heat range is very important. But even a spark plug featuring a properly selected heat range, is influenced by the processes of fouling and self-cleaning of the insulator tip. The setting of combustion deposits on the insulator tip is caused by an imperfect combustion due to a "rich" air/fuel mixture. On the other hand, the combustion deposits previously set will burn if the insulator tip temperature rises above 475 °C.
Zones of spark plug fouling and self-cleaning zone depending on the air/fuel ratio and on the spark plug insulator tip temperature.

https://www.briskusa.com/spark_plug_...at_range_chart
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