One of my friends was telling me i should bore out my engine and i was wondering what that was and what does it do, he said it was a big performance upgrade

 

Enlarging the diameter of the cyclinders is referd to boring. It will not do much in terms of perforamance by itself. Not to mention expensive. If youwere to rebuild the current motor, bore it, raise the compression ration, put a decent cam in it, and port the heads, it would be all right. You would need all new pistons and related hardware, the motor would have to come out, and it pointless unless its part of a bigger, better package.

 

boring is usually done to fix scratched cylinders walls,or out of round ones when rebuilding, not to increase displacement.

 

Well - obviously (having worked in a machine shop and knowing the deals) some people use boring as a repair option and others use it for increased performance - but keep in mind boring the block and adding bigger pistons means less gas mileage and more work in recalibrating your fuel/air intake systems to compensate for the change in piston size (engine displacement). For less hassle have it resleeved to the original piston sizes and revamp the rest (new gaskets and such) - for example three years ago my local engine builder was dropping sleeves for $100 ea. so for a V-8 you'd be looking at about $800 + tax and crap. Usually many engine parts are reused if they weren't scarred ( like crankshaft, connecting rods, etc.). When rebuilding yourself pay special attention to cam and lifters though - they are often first to wipe out (in a non-roller block) on their lift lobes and surfaces.