How did they ported & polished the UIM?
It's not possible. Not in the truest sense of the terms.
They could do it to the last few inches of each port, but not any deeper. Hence the reason for needing the EH process...
Also you do not want the sides of the manifold to be polished smooth.
Wayne - The EH process was done on a bare UIM. Then the manifold was powdercoated. Then the surfaces were machined.
This is why you can get powdercoating (sand paper) inside the ports (I had none personally) and the mating surfaces roll into the airflow of the ports. (I had that on every port!)
