How much cfm out of a valve job?

[2002_red_gts]

Just got off the phone with Mr. Killians (head ported) he flowed my heads today and got 280 at .600" but said the the valves need a valve job bad and where leaking. He stated that I could see 3% up to 10% in flow from a could valve job. I was hoping for 290cfm do you think a valve job will get me there?

 

[DrumrBoy]

The degree of leak means its not sealing well.....leakage doesn't have much to do with flow...except that if the interior surface of the valves is nasty, then flow over that surface won;t be so good. I wouldn't imagine you'd get a lot of extra flow but folks who're more experienced on the flow bench than me will chime in soon. Good luck with the build anyhow.

 

[2002_red_gts]

Thanks! From what I have been reading it looks like 10 cfm is the norm but more depending on the degree of the cuts or if it back cut. I hope Mr. Good will jump in

 

[Greg Good Cylinder Heads]

Is this after he did some porting, but has not done a competition valve job yet?

 

[FastMatt]

Is this after he did some porting, but has not done a competition valve job yet?

Thats what I was thinking, who ports heads and does not do a valve job after? I have never even herd of such a thing.

 

[2002_red_gts]

Well he was going to send them to a local guy to do it since he just ports them. Buy I told him I'll just have it done here in San Diego