sr20de4evr

i have a Ser and i wanted to know about porting and polishind the cylinder head? what benifits do i get and what not to do and especially precautions to make .. please give me some info on this subject! i would very much appreciate it.

Never done it myself or seen it done, so I can't give you any tips there. I do know the head on the qr is very efficient, you would see very little gain from porting and polishing it.