dw456post

What do you think about these plugs? I pulled them out of my 5.3 with a Whipple blower--14# max. They have about 15 short WOT runs with a short drive each way. I am using octane booster, for about 6 of the runs. Cranks and idles OK, idle is tad rich but the O2 sensors take care of that. WOT is about 10% rich on these runs. I have a new set of plugs coming , WOT is only about 3% rich now. The first two threads are a little wet from fuel---210 injectors.

IGN-1A

Hi, the "octane booster" will change the color of the insulator, no Fire Band observed.
Ground electrode NOT melted.
Lance

dw456post

I cut 4 more and there was a fuel ring visible, but not like a pencil line. I have been tuning a new engine and it has been running rich for several passes, plus idle and drive around time. I guess that's why the ring is not straight. I will check the new plugs after one run.

IGN-1A

Ok, "normal" fuel will burn off at 1/2 of the insulator stating the plug heat range is corrrect.
Thus White at the tip side.

dw456post

Here is the new plug after two runs. Fuel band is visible and shows rich---wideband showed rich also. Fixed that.
Timing looks good on the ground strap.

IGN-1A

Hi, I agree.