Do you think a rough textured intake runner also helps break up the fuel mixture? If that's the case should the exhaust be smoother to be more efficient? I'm thinking about why the intake doesn't perform as well with smooth flow.
There are two guys that come to mind when talk about port texturing comes up. Larry Meaux and Chad Spier.
I've had 2 phone calls with LM and several with CS. I personally have never been able to duplicate their results. Every time I do a burr finish the power is the same, but BSFC goes up.
IMO, the shapes and geometry of the surface is as much or more important than surface finish. I finish all my intake ports and manifolds at 60-80 grit and the exhaust port at 120 grit. Combustion chambers I do a mirror finish. That is how I get the lowest BSFC numbers.