Die Grider with fine aluminum cutting bits (spade shape), and various sanding rolls. went from 30 grit down to 80/120

Wow lol. Yeah... nice. I have a dremel... I shall work with that lol. I gotta pick up a carbide bit to cut with... and figure out exactly how to find the center of the port by reading those threads.

why not mirror like, is that bad? or does it just not yeild you any results? (thuse being a waist)

Mirror finish is bad. The air is static at the port walls. I was always told with a slightly rough finish, the air fills in the tiny gaps left by the finish and gives the air that actually moves a surface to slide over. Air won't stick to air, or something along those lines, but air will stick to metal.

Please correct my errors.

Actually, your right on with that

This is why I leave the bottom of the L67 LIM rough. And don't fully polish the inlet of the SC to a mirror.

The SC outlet, however, I do polish to a mirror so that EGR/PCV grime doesn't have a rough surface to build up on. These deposits create tiny points of heat under boost.

Even my cylinder head porting wasn't a full-polish surface. I left a certain amount of roughness.

The rule I try to follow is a mirror finish ONLY in the areas where gunk buildup will be a potential problem. Semi-smooth finish elsewhere. The finest grit I use on LIM runners is 80.

so what about themirror finnish I put on mt SC inlet? no one told me at the time it was bad.. I know the SC builds alot of crap in the inlet sao wouldnt the mirror be good for keeping awat the resrictive build up?

the difference between mirror finish and a finish that i showed is 15-20 cfm at 28"

(keep in mind my mirror polish on the SC outlets is only on the extreme edges)

Golf balls are dimpled for the same reason. :P