Spark plug discoloration temperature

What is the temperature at which the cad plating on the ring of the spark plug starts to discolor? I read this somewhere and can't remember where.

Thanks

Greg

 

Reading Spark Plugs

You've probably seen it already but Mike Canter has written an excellent article on this subject, it may help you.
Go to: http://www.dragstuff.com/techarticles/reading-alcohol-spark-plugs.html

 

Thanks for the response Dave.

I am very familiar with Mike's article. I am trying to corelate the actual cylinder temperature to the plug discoloration on the ring. I know the plating discolors or starts to burn off at a certain temperature, just trying to figure out what that temperature is.

Thanks

Greg

 

"actual cylinder temperature" I don't think many would actually have combustion temp's. But if your refering to EGT's that will vary so much from each application not sure that would be useful for you to corelate to your plug read.

You might try contacting NGK tech department if you want to pursue.

That's my thoughts anyway...............blessings..........Ron Clevenger.