i just put my gsr together w/ new rings, valve seals,valves, and all the gaskets/seals.......anyway, it's been 1000 miles since the rebuild. At 500 miles i switched over to full synthetic and it was fine till tonight when i was racing another hatch, all of a sudden when i hit around 7000 rpm in second smoke started pouring out the back of my car all the way through 3rd. So i pull over to see if anythings leaking.....nothing.....then i rev it all the way to redline.....nothing. I checked the oil and it's about a half quart low........it doesn't smoke during regular driving....just when im at high rpm........whats up?

 

do a leakdown test