My motor constantly seems like its fouling out plugs because it will only idle around 1,000 rpm for 30 seconds before it gradually dies, an the idle screws are adjusted right, and the power valve is not blown. It think its the plugs........I'm running autolite 3924's, what should I be running?? I'm also running a shot of nitrous so what plugs should I be running to go a heat range cooler? And when they say heat rang cooler................what exactly do they mean?? a heat range cooler than WHAT???

 

Check with Jegs, I went from GM Iron #461s to AFR 195s and bought a new set of the same plugs I had been using before and after the head swap it would foul them and the motor had terrible throttle responce. I was dumbfounded...

I had a set of brodix Track 1s laying around, so I screwed in a plug. It was about 1/4" from even making it out of the threads and into the combustion chamber.

Here is what I found on spark plug heat ranges....

http://www.nagca.com/grandtech/sparkplugheat.htm