I thought oil was black and fuel was bluish. Because, my car right now is running with tons of smoke coming out of the back and it is a bluish smoke. I can back that idea because I know my car is running rich. I have a swapped gsr into a civic. I have to get an aftermarket adjustable fuel pressure regulator so that I can lower my fuel ratio that way I run better and take the risk away of detonating the head. Also, how exactly do you detonate the head? I ran rich tonight racing 4 times and nothing happened. I would suggest to you that you somehow check the fuel pressure and make sure its not off. Also, take your intake off and while reving your motor at around 3 grand, spray carb cleaner into your throttle body. This should help clean carb build up if you have any. That can cause smoke sometimes. I know I have carb build up like a mother because I put new denso spark plugs in, idled the car for 3 minutes and took them back out and they were covered in black crap. I mean the way a very old spark plug looks. Its crazy!