I replaced my plugs yesterday and some of them were red in color????? I have never heard of this. None of them had oil on them. Some were gray, but most were this dark red color. What does this mean for my new engine?
I had ACDelco plugs in there and now I have NGK. I have an accel coil and 8mm wires that are going to be replaced soon.
Jeff are you using octane boost? This will cause the plugs to be red/orange. If you used any kind of gas additive this could be why your plugs were red in color. That is not a problem. I would expect them all to be red though and not just a few of them. Some maybe a liitle more red than others.
I did use octane boost but I haven't in awhile. I wasn't sure what the situation would be when I started. I have 10.2:1 and cast iron heads so I have slowly backed off the octane rating until I have gotten to the present of 89. Do you think I could live at 87? I doubt it.
10.2 - 1 with cast irons heads is pushing it even on 91,92,93 octane depending on where you live this is the best you can get at the pump. You must have one very healthy cam in that engine (lots of overlap). If not that popping sound you are hearing (from your other post) might just be detonation. I would suggest running premium in that engine. Are you positive it is actually 10.2 to 1? If so I am surprised you can get by with 89 octane.