my gsr hatch smokes really bad and i went to get it looked at and the guy said the guy who had it before me probably built it loose. what does that mean and what are the advantages

 

probably means the clearences were left loose. not really a good idea for a street engine.

 

loose clearance usually makes the engine have a diesel like sound and in a worst case scenario at high rpms could lead to a cracked sleeve. If the sound is not there then more than likely you have some bad piston rings or a blown head gasket. Check the compression in your cylinders before doing anything and see what you get. If that checks bad then you know the problem.