Alright I was out at the track. Decided to run colder plugs so I could run higher octane fuel (normally run the platinum +4's) so i dropped in NGK's. After the swap I noticed something wasn't right but ran it anyway. Come to find out the #1 cylinder was firing at all due to the bent plug (dont' know how it bent), still ran a 16.6 on 3 cylinders Made two more runs and noticed I was running 2 tenths of a second slower than with the other plugs. When I started to swap back, all the plugs came easy except #2. When I finally got it out and examined the threads of the plug, there was metal melted in between the threads!!! Since none of the others were like this, I'm stumped.

What would cause a single cylinder to run this hot?


Modified by TxTuner at 2:45 PM 5/13/2005

 

Bump, someones gotta have some sort of idea

 

Sounds like you might have crossthreaded the plug when you installed it. When removing a crossthreaded plug, the friction between the hard steel plug threads and the soft aluminum threads actually fuse some of the aluminum to the steel. That is why you see metal on the threads.
If you were running into detonation, or the plug was running too hot beacuse of a lean fuel mixture, either the ground electrode or the center electrode would start to melt. So I don't think that is your problem.

 

that's what I figured but I'd never seen aluminum left on the plug after cross-threading