on the very very tip of the plugs, i have orange. it almost looks like rust! its on 4 of them...

2 of those 4 are also black on one side, white on the other. sorta melted looking too... i assume i ran into some detonation and replaced them of course.

but wheres the orange coming from? never seen bright rusty orange on the tip of a plug before.

Also let me add the fact I have not run N20 on these plugs..
and these are AC Delco 5's. long style for my heads.. Indexed for the flame front.

 

if it was a LIGHT orange flaky deposit then it is detonation.

if its darker orange red color to the plug itself then it could be fuel additive or winter gas doing it.

BTW if the plugs are colored TAN it is good.

 

If you got black on ONE SIDE of the plug's porcelain then it's almost certainly oil coming in through the intake valve (bad valve guies or guide seals).

Wanna know for sure? Put a magic marker line on the outside of the plug that's in line with the black mark on the porcelain electrode on the inside of the plug. Put the plug back IN THE SAME PLUG HOLE IT CAME OUT OF and tighten normally (or this test will be meaningless). Does the magic marker line point at the intake valve for that cylinder? I bet it does.

Oil has a much lower octane rating than gasoline. If you're marginal on detonation to begin with this slight oil consumption could be causing detonation on those affected cylinders.

 

Orange will also show up if you using to much octane.

2 gal motorcycle tank, half a can of 104+ that does 22 gallons
= plugs so orange they look tasty.