Looking for some opinions here. If you have a head porter that does great work, do you think you can take a head and make it flow almost like one that has been cnc machined? Someone has to port the cnc head by hand first right, before the program can be setup to be done by computer?

I'm wondering what you guys think about taking a set of heads like a dart pro1 200 or canfield 195 or a pro-topline 200 aluminum head and be able to get the same flow as a afr 195 street cnc'd head? I know the afr are supposed to be the best, but do you think with work, these others can be just as good or better?

Your kidding right? Actually I'm kidding ya and giving you crap. Your correct that a CNC'ed head has been hand ported first and the runner and combustion chamber are then digitally measured then programmed into the CNC machine. The CNC can then pound out one head after another with each one being consistant and at a high production rate. The CNC also does not require health benefits, doesn't call in sick, and does not steal company property when your not looking.

Just because a head is CNC'ed though doesn't mean it's the greatest thing since sliced bread. The porter we use has both a CNC machine and does a lot of work by hand as well. I know for a fact that soem simple mods in the short side and bowl to say an AFR 195 head, by hand, will significantly pick up the flow on those heads. So the short answer is yes, a porter who knows his stuff relative to airflow can easily exceed the ratings of an AFR on a set of Dart's or Canfields. The Topline, I have no idea as I have no experience with those heads. With the Canfield and Darts you should be able to get those heads to flow above 300CFM quite easily, compared to the 260 range with the AFR's stock or in the 285-290 ported out.



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70 SS 454 CI Dynoed 684 HP, 702 TQ All Aluminium Fuel Injected Small Block , plus 200 - 500 HP NX nitrous system.

Nobody else wants to get in on this?? Thanks for the info rick. What do you think on the afr's? Go all out and get them and touch them up or start from scratch and get the darts and hog them out and get all the parts. It comes out pretty close in money by the time you figure the work and parts in, vs the afr's done with some touch ups.

RickWi- Just curious who you use for head porting and what his rates are for say a 195 AFR head?

We have a guy under contract that worked for a Bush builder who ended up closing the doors and moving to North Carolina or South Carolina, can't remember which.

For porting a head like an AFR it's best to start out with a fully CNC'ed head and then have it "tweaked". Reason being a raw casting would take 40 or so hours to bring it up to the level of a 5 axis CNC port job. Usually better to have the CNC machine rap that out from the factory. Tweaking the head from there via hand porting and valve work then takes a day or so of labor, usually around $600 to $800 bucks for a set of AFR's.

On a Dart Pro 1 I think you just get them as cast, bare and then have them optimized. If you'd like I can do some checking and get some details on what he would suggest.

As to what I think of AFR's, I ran them through the 90's on my 383 and think they are a very good head.

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70 SS 454 CI Dynoed 684 HP, 702 TQ All Aluminium Fuel Injected Small Block , plus 200 - 500 HP NX nitrous system.

Hey Rick, for finishing of the AFR's what are you changing? Do you just smooth out the tool marks and short side radius, then back cut the valves or is there more to it? I presume you aren't hogging after the precise CNC work is done. http://www.nastyz28.com/ubb/wink.gif

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Custom Auto, your source for quality machine work, cores and new parts at competetive pricing right here in British Columbia 1-888-563-4050
A Canadian, EH? (with a 10 second street car)

<font face="Arial,Verdana" size="2">Originally posted by rustbucket79:
Hey Rick, for finishing of the AFR's what are you changing? Do you just smooth out the tool marks and short side radius, then back cut the valves or is there more to it? I presume you aren't hogging after the precise CNC work is done. http://www.nastyz28.com/ubb/wink.gif

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Throat area, shortside work, valve work (with either REV or Ferrea valves) and chamber/blending work. Yes as well to all the tool marks, the runners are all nicely hand finished. It's around $600 to $700 plus valves. There is not a lot of room in the runners to further hog out. The max I could get my 190's to was 206 cc's when I ran them on a 383. Lot's of dough down the drain on that fiasco for not a lot of flow, if any, from the runner work.

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70 SS 454 CI Dynoed 684 HP, 702 TQ All Aluminium Fuel Injected Small Block , plus 200 - 500 HP NX nitrous system.

Thanks for the reply Rick!
I wondered about that as I was working with a set of AFR 357's last spring, but there was no way the heads would be the limiting factor of the shortblock they were going on. With the price of the AFR's most people around here would laugh in your face if you said you needed to tack on another day or two of labour to finish off a set of heads most would say are finished "as is". Naturally, unless I end up with a set of heads that are already polished, I couldn't leave well enough alone, I'd have to smooth out the CNC marks for myself.

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Custom Auto, your source for quality machine work, cores and new parts at competetive pricing right here in British Columbia 1-888-563-4050
A Canadian, EH? (with a 10 second street car)

Usually the folks building motors with decent heads like AFR's Brodix, Edelbrock are pretty easy to sell. When you put the heads on the flow bench (with them standing there) and overlay the their flow numbers with a head that has been prepped it's like looking at a dyno comparison. One flow curve towers over another, with theirs on the bottom. This past week we did a flow test on a set of Ford racing heads with the intake and lost 20 CFM, that's not gonna cut it for a guy installing this motor into a Cobra Kit Car. The intake is now getting worked over.



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70 SS 454 CI Dynoed 684 HP, 702 TQ All Aluminium Fuel Injected Small Block , plus 200 - 500 HP NX nitrous system.

Other than doing a thorough port match I've never played internally with an intake. Do you use a manometer to check where the flow issues are or was it trial and error until you got the basics figured out? I wouldn't mind working on my Vic Jr but without knowing where to carve it would only be a crap shoot.

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Custom Auto, your source for quality machine work, cores and new parts at competetive pricing right here in British Columbia 1-888-563-4050
A Canadian, EH? (with a 10 second street car)

Gary and Mark do all the grinding. A couple of things they look at is cross section and plenum volume. They measure the thickness of the intake walls and start doing their tricks. They will try a couple of things, throw it back on the bench and if they are going the right direction they keep on going. How they know what to do is beyond me. They both have been doing this for a long time though and I suspect it's knowledge gathered from a ton of trial and error over the years.

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70 SS 454 CI Dynoed 684 HP, 702 TQ All Aluminium Fuel Injected Small Block , plus 200 - 500 HP NX nitrous system.