WRONG, there are also several people here on this site that have had to modify their valve reliefs in their non tw pistons due to insufficient valve clearance issues. One of these has been within the last 60 days, lol.
If they did, its not the norm.
Wrong AGAIN, lol. It's a FACT that there have been recent valve guide failures on TW heads. Just because you are not aware of this FACT does NOT fix the people heads that have had this problem.
So how do you explain the 1000's upon 1000's of engines that use the TW head, and dont have these problems? You cant blame the head design because someone set the valve geometry wrong.
And just so you know, not all flow charts are the same. The one I used were all comparative in nature.
Post up the link of where these charts are. Because, if you go off of the numbers on AFRs website, then most of those charts are from numbers gotten from using a larger bore as compared to what the others tend to use. That alone inflates the numbers.
I suggest you tell it to Joe Sherman.
Plenty of guys with tons of experience have questioned some of Joes numbers. No doubt he is a good engine builder though. But he is not the only builder on the planet. Plenty of builders can do what Joe can do, and do it without AFR heads.
I find it odd you automatically jumped into a AFR vs TW debate. Plenty of other heads out there, and lots of them do better than both of them. You just assumed I was talking about a TW. I dont even run TW heads. Ive worked with them, as I have the AFRs. They are both good heads.
Point is, AFR heads arent the best head out there. If thats your opinion, then thats fine, its yours to have. But to state it as fact is misleading and false.