Was out goofing around the other night, things seemed OK. Race a car with very loud exhaust, two races. Nothing too exciting. Drive home I romp on it once and it's pinging like a MO-FO! WTF!? Somehow decided to go for 40° timing. I finally got around to pulling the plugs tonight and crap.. Speckles on most, porcelain eroded off others, rainbow on a couple straps. Here's two samples. What's with the speckles? and what causes the porcelain to erode like that around the positive electrode?
I compression tested it, 145-160 all around. Thinking about borrowing a bore scope. What should I expect to see? You guys think it's hurt?
Pictures not resized smaller for better clarity. Note: I use bronze looking anti-seize, that's not rust. And my drive home was 15-20 miles of in town driving, so the mixture is/was all over the place for the rest of the discoloration.