I just got my car back a month ago from having it completely rebuilt (everything is new in the engine).. I've began to notice when I first start it that smoke blows out the tailpipe and uses a bit of oil. I can't really tell if its blue or white smoke but it might have a little blue tint to it. I was wondering how long it takes for the rings to set or is there a certain period in which they HAVE to seat in. I've put around 600 miles on the motor. It does it only when started and revved before warmed up, then I drive it around 15 or so miles park it n rev it up and don't see any smoke. I'm at a loss.

 

sounds like bad valve guide seals. Nothing TOO much to worry about. Your engine isn't in serious trouble or anything, if that makes you feel any better.

Edit: i really should read things thoroughly before i start making comments lol.... disregard my post