CNC Mill Mark Removal in Intake Port

One more thought………
If trying to determine if/how much the surface finish may impact flow numbers on the bench…….
I feel that the “test piece” has to be one without inherent flaws to its shape.
One that doesn’t have a compromised form, but does have a well developed valve seat & chamber area.
No meaningful flow turbulence or flow regression until well past the usable lift range.

And even then, I’m not sure how accurate the flow results would be in determining how the different finishes impact the power output.