Com'on Karl - that's just a little glow. LOL. I wanted to see photos of red hot headers. :poke:
Seriously. That makes sense. Retarded means the burn is finishing later, and therefore more heat into the walls and exhaust port.
By default my engines were broken in with manifolds.
However Rob broke in somebodies engine on his test stand using the TTI shorties that were coated with zirconium dioxide.
Didn't affect them at all.
Good thing too - since he neglected to tell me that he had used them when I listed then for sale. :rolleyes: