C-heads info needed

What r the normal flow numbers for a c head out of the box? I had my heads flowed first and then chambers and bowl blending and then minimal runner clean up and exhaust clean up and then flowed again ....

Im not to happy with numbers but is it all about the numbers? .will post before and after as soon as i get paper work

They really are not a head good for use out of the box. Its the porting, Valve Sizing and shape and valve job them make them sing.

There is no ...out-of-the-box flow # for the C460 head.....they do not have a valve job as delivered.

Without the sheet in front of me they flowed on an average of 370 ish unported now there 476 ish

badnotch wrote:What r the normal flow numbers for a c head out of the box? I had my heads flowed first and then chambers and bowl blending and then minimal runner clean up and exhaust clean up and then flowed again ....

Im not to happy with numbers but is it all about the numbers? .will post before and after as soon as i get paper work

Gery you are one weird dude first you aks a question the you come back and answer it....yourself

Charlie's info for ported C's is in the archives. The numbers will be what they are, but if that is a hand ported set of heads, they aren't that bad.

work from the turns into thev bowl with the correct V/J will get 490's cfm , rest of the port is just clean up .

forgot 2.400" int. valve

Thanks coug im.glad my questilns amuse you

Gerry, I'm in no way a expert at all on a C head. But,just from what I've seen,the C head is a mfg Racing head cast w/o valve jobs or runners completed for competition. They kinda do that because everyone has their own desired application for the head. 470 is probably normal flow for just enoughport work to use it. A cnc program or a expert stage 3 port job will get 500+ easily.

As several have commented, the C head is a great playground for a head porter. Engine Systems (ESI) has several shop engines that average in the mid to high 1100 HP range with C heads and single carbs on gas. These heads flow in the 500-505 CFM range at higher lifts. A recent freshen-up on a buddys 638 netted 1176 HP and I validated his flow numbers just for the sake of curiosity. They were a hair over 500 CFM.
Ted (at ESI) has been porting the C heads, just like many of the other "seasoned" head porters lurking on this forum, for several years and most C headed BBFs simply haul ass with a decent port/valve job. Last month Ted used some of our learnings from the KFM Interceptor project, and stepped into a different mind frame on his typical C460 port job. End result was a little over 1230 HP on a wet sump single carbed 632 (or maybe 638..)
I know that Charlie, Phillip and others are also playing in the same power ranges with great dyno and on-track numbers. Where permitted by class, the C460 head is pretty darned good. They just need attention from a pro that has done many sets.
Just my opinion....
Keith

I understand i thought they were a better head then that out of box ....well they sure seemed to.like my 11:1 600" roller cam.shaft ...i guess i get caught up in the numbers game

Gerry w/a low compression street/strip small cammed engine like yours,you are actually in better shape w/a head that flowed less.jmo

Well i guess we will find out in a couple years buying mom&dads house r.i.p. dad ) .....ill ne happy if it makes 1050sense with a nitrous camshaff and on spray it should move out

Thanks for your input Coug............