There was a thread a few years back . One guy claimed .3 and 4mph on a valve size change. I think he went from a 2.48 EV to 2.52 EV using the same cam. It's kinda a hot button issue when you involve professional head porters and the given guide lines to developing a good head for an application.any advantage to bigger port and valve on exhaust side??
No need in buffing the heat will smooth the port.
This is the port I'm talking about. Valve size is 1.65" and flows 325+cfm straight off the CNC. I am going to do a little blending and buffing to avoid any kind of build up on the tool path ridges. It may pick up a few cfm from this hand work.