Higher Compression motors and spark plug needs.

[RobHughes]

Back to raising the compression ratio thing again..lol

Is there a "stock" guideline one would adhear to when raising the compression ratio (8.5:1 to 10.5:1) in regard to heat range and electrode gap?

Thanks again!

 

[Metalguy]

The basic "rule of them" is to go slightly colder and use a slightly smaller gap, but there are many variables. Just remember to err on the cold side, because too-hot plugs can be much worse($$$$)than the nusiance that too-cold plugs are.