1. Port and polished?

 

ports on the cylinder head are enlarged and polished for more air flow this is mesured in CFM

 

but if you POLISH the ports, you kill air flow. Only go as high as 120 grit on the flapper wheel.

 

polished ports = improved flow...!!!

 

Polished smooth does NOT mean improved flow. I could give you some analogies involving water along the edge of a stream versus the water in the center of the stream being totally unaffected, but I won't. The porting is the most influential aspect of P&P because it's the shaping of the chambers that determines air velicity through those chambers which determines power.

 

You should only do a mild port/polish job, doing too much can hurt the car.