port polished head... who what where when why how?
 

what exactly does that mean? Does it add power?

Ported- intake and exhaust ports are bored out to be larger or more free flowing...

Polished... makes it shiny shiny..

I'm sure it adds decent power but not enough to justify the cost unless you have the head off already...

It's mainly a last thing people do to squeeze out that last drop of power... (also it makes MORE of a difference the more power you have now so if you're stock it won't do much but if you're turboed it'll help out considerably).

It's kinda like a throttle body... not really neccisary and the money could be spent better elsewhere unless you're out of elsewheres.

yea, and a little more on the subject..

more flow= mo' betta. Atleast in some terms. With less turbulence from the "polish" job, more crap gets moved with ease.

but polishing can cause TOO smooth flow giving worse air/fuel mixing capabilities...

Also misted fuel sticks to smooth surfaces... where the roughness in casting stirs up the air against the walls so the fuel doesn't really have a chance to stick (as it's being blown of as air bounces off the rough-edged wall.)

If you spray whatever onto both a polished surface and a rough casted surface you'll notice the cast surface prevents it from pooling and becoming a liquid again... where the polished smooth surface allows all of the tiny droplets of water to re-connect and become more of a "puddle".