What happens to an engine if you use a plug that is too hot or cold? What are the effects to the engine? Does to hot of plug make the car run faster, slower, etc? I have always run 8's in my engines but this is the lowest compression ratio of all of them.

So a 10 is what I should be running? Anymore info any of you want to know? I have way to much money in this engine and I dont want to cause damage for something as simple as a plug.

Thanks

Chuck