Flow Numbers: Deciphering

[skinny z]

That's correct, Kevin.

I edited this post as I saw that you had tested to .550".
Point of curiosity, how do your numbers stack up against Dart's advertising? (Difficult to compare across benches I know).

[RevTheory]

All I've got in this drawer here is the sheet that came with them listing 259 at .500 and I'm guessing that's from their development port on the best day, lol. I don't remember if their website had more data or not. It looks like I was on the way to a decent head before it took a swan dive.

[steve cowan]

This is not a dig at Revs cylinder heads at all but an observation,
Around that 450 thou range is the convergence point that the air does not know which way to turn,I have mentioned before but all my low port 23 degree heads all had the same problem as cast.you can see Shaun has done port and chamber work on those dart heads but the bench shows it hitting a wall at 450 lift and above. It shows how important it is getting the height/ shape correct to get the mid/ high lift numbers.
My dart 180cc heads are 206cc with average CSA of 2.3" on my bench flow 290cfm @ 28" at 700"
At 45" depression with manifold they flow an average 310cfm on all runners.