[sohc_vtec 2NR]

yeah...get a b series engine..but if you have no choice with the d16y8 then port and polish would be right thing to do, assuming you've exhausted all of your bolt-on mods (if not then do that first).

i myself have this engine but the most extreme mod i would do is a new set of camshaft. i feel that port and polish would best suit the b series engine-it has a much greater potential in HP gain.

as for your questions..there's great power to be had with the port and polish in conjunction with intake, exhaust and among other mods of course, but the price won't be cheap! as a rule of thumb: anything to do with getting inside the engine will NOT be cheap

basically a port and polish is increasing the size of the engine's intake and exhaust port thus increasing the flow of dense air into the combustion chamber and the larger exhaust port diameter will let more exhaust air out of the engine- therefore increasing the engine's volumetric efficiency. i thinks that's right..well correct me if i'm wrong... hope that helps