Looks like the exhaust is crossing over the intake seat. All of the research that I've done on this and machine shops that I've talked to said that there has to be a minimum of.030" better the valve's. Is this true?
It’s funny you ask this. We were flowing a set of heads my buddy ported on Wednesday and we were talking about valves and a 2.100 valve entered the discussion. He’s an engineer and 10 times smarter than me so we kick things back and forth between us all the time. He commented about Indy heads having a bigger valve but I told him Edelbrock heads valves are pretty close with a 2.08 valve. We took a fast look at his Speedmaster and guessed .040 between them. Well when I saw your post I checked the set of Edelbrock heads I’m doing for myself and it more like .030 clearance. Just for kicks I may order a 2.100 valve, cut down an exhaust valve slightly for more clearance and give it a whirl. I’m pushing [email protected] and [email protected] lift. The 6 cfm isn’t that jumpy at least compared to the 15-20 I’ve seen on an Airwolf head but it’s more than I like to see. If a 2.100 valve calmed it just a touch and added 10cfm it would force me to jump up from my .650 lift cam. I go more by airspeed on the exhaust anyway so I could give up a little valve size on the exhaust valve. My flowbench head fixture is 4.015 and my block is 4.030