The C61CX is at the top of the heat range! They make a C63CX and it is at the top. They also make cooler C59CX, C57CX, C55CX and C53CX. I have attached a chart showing these numbers hot to cold. So my C61CX is one of the hottest heat cycle plugs. So now my question is how far to go down in heat range?
Thanks! MJ
Rule number one is NEVER use a cross reference for plug heat ranges. They are somewhat close approximations, but not good enough to use as a fool proof heat range indicator.
Again, like I said, I don't think you need the cut back ground wire plug. At your compression ratio, you just don't need it.
IMO, you'll be better off with an extended tip plug.
The C65YC and the C65C are both two ranges hotter than what you are running.
I'd have to look but I'd bet the plug that Porter just posted isn't a cutback ground wire plug.
So as I said, I'd order the hotter plugs and start over after you verify TDC and your timing light.
Don't be married to the CX plug. It may look cool but you just don't need it.
