OneWheelDrive, the golding of the head is due to taking the paint beyond its temperature threshold, as far as I can tell. It's engine paint, and it bubbled to give you a feel for the heat. You'll notice it happened on the cylinder, too, just not as bad. I figure that might be due to the cylinder having steel sleeves for bores. Maybe it didn't get as hot. Dunno. Just conjecture at this point.