i have been chasing a top end power problem in my race car since changing a camshaft to one with more duration and lift, this cam should have been on the money with the flow figures that are advertised, RPM and boost we are running etc,

so i pulled the heads off and sent them to one of the countrys best head porters to get them looked at and the flow is well under the advertised flow rates, the intake was 40cfm down the advertised 315cfm and the exhaust was 35cfm down from the advertised 237cfm at .600, this is more than 10% down on advertised..

so has anyone flowed them and what were the figures you got?

 

Every time I've flowed AFR 225 heads, they were above the published flow numbers. AFR is very careful to publish conservative flow numbers. This way, they always perform at or above advertised when flow by an independant facility. I am surprised to hear about your flow numbers being so far down. A rare occurance for sure.

 

so what figures do you get and what is the test bench?

 

flow benches do vary...correction factors, inlet radius, Ex. flowed w/pipe, etc.
also the valve seat starts narrow and tight but gets hammered over time and
flows less as it gets wider (sometimes due to wasted springs bouncing)
Send them back to Tony Mamo for a freshen up.....AFR's are known for very
accurate flow numbers !!!!

 

yep flow benches are like dynos, thats why im after actual numbers people have tested them to and on what bench so i can compare etc..

everyone is telling me they flow more than advertised, but so far no one has come up with some flow figures..

my porter picked up 12cfm on the intake and 25cfm on the exhaust with a quick clean up so im pretty confident the figures are going to be on the money when i get them back and spec the cam to suit etc...

 

Those heads have been around for so long, I'm sure if you search to like 2005, you can see lots of threads with flow numbers. Just do a search. I know there are at least 3-4 threads I've started over the years that have some AFR 205/225/230 flow numbers in them.

 

So based on the math your telling me that your porter quoted you 275-280 CFM on the intake side??

Seriously that is beyond highly unlikely....it's so low its almost impossible unless that port was completely molested after it left AFR (we haven't produced a 225 AFR in probably 18-24 months).

Even more bizarre is at the end of the day one of the country's best head porters (per your claim) picked it up only 12 CFM so now it flows 285 - 290 CFM?? (once again just doing the math). Those results would be pretty shabby considering a typical ported stock casting flows 290 - 300 CFM by an average shop and a ported aftermarket casting offers a bunch more potential (I see in the vicinity of 330 CFM from some of the 225's I have personally tweaked for a little more flow).

The whole thing seems a bit odd and it leads me to question all the information you were given.

I have seen literally hundreds of 225's cross my bench.....I don't think I ever saw one that flowed under 310 CFM and even that is a stretch....most flowed right around 320 CFM. The 225 heads on my 383 were milled a bunch which hurts flow a little and still flowed right around 315 CFM. The power these heads typically generate would be impossible with the flow figures your porter has quoted you unless they have been seriously molested and even then it would be difficult to believe they flowed that little unless he didn't have a radius plate in front of the intake port or the valve job was really jacked up badly (I think a raw seat would still flow close to 300 CFM's).

Lets keep in mind that porters are in business to make money porting heads.....an independent assessment of the head is typically better.

I would have looked the head over for free had you contacted me and sent them to our facility just to put your mind at ease assuming they were in fact out of the box heads. A PM or a call to AFR would have went a long way here prior to giving your shop the green light to work on the heads.

I cant help you now unfortunately but I post this on behalf of others that might find themselves in a somewhat similar situation.....although if I can be of any assistance shoot me a PM and we can go from there. I really do wish you would have reached out prior to moving forward with anything. Not much anyone can do then.

Thanks,
Tony

 

spending $600 on shipping to send the heads back to the USA and back again is hardley worth it.

ill get you all the flow figures next week,

i fitted a set of 230's to a car this week i should have sent them to the same bench for flowing before fitting them..

 

I sell a good amount of Tony's heads and we have had some flow tested and they have always been better the numbers they claim. I'm very sure that the 210s I got from AFT is the main reason my N/A Gen I SBC was able to make almost 600 in a pump gas driveable setup! Thumbs up to Tony and AFR!!

 

Might just be like there dyno readings they are alway's higher than ours

 

Tony - these heads are BAD, I meant to get in touch with you about them before XMas but ran out of time.

Flow bench is pretty good - SF600 with Audie flow tech, most AFR heads I've flowed on it have actually come pretty close to your advertised figures, I'm not gonna bash on AFR stuff, I personaly think bang for buck they are some of the best heads on the market.

But these one have been butchered a bit, truly horrible valve job.
Another factor that will have affected the figures is that I didn't realise your figures are based on a 4.125" bore, these were tested on a 4" bore as thats what they'll be sitting on.

These are the numbers off the heads before work:

.1 - 70.5
.2 - 145.1
.3 - 214.6
.4 - 267.4
.5 - 299.6
.6 - 291.2
.7 - 290.7
.75 - 291.0

Exhaust
.1 - 50.8
.2 - 97.8
.3 - 139.2
.4 - 177.4
.5 - 195.9
.6 - 206.8
.7 - 212.4
.75 - 213.7

As you can see they fall off a cliff over .500" lift, very turbulent & seperating over the turn.

Now, the seats are almost .040" lower than stock & have been cut wth a sharp edge in to the alloy, to fix them 'properly' I'd need to weld up all the insert holes & fit new inserts - which I figure is probably a bad idea on a turbo'd engine, so instead I cut a fresh seat, recut the chamber relief & reshaped by hand.
Just a clean up from there to get a baseline, that picked them up up top no probs, they no longer back up hard but they do still fall flat.
Left it at that & went on my xmas break.

Had another look & a think today, recut 1 seat to a different profile & have reworked the 1 port quite a lot, not done with it yet but I'll report how it comes up when I'm happy with it.
To be fair I think the problems with these heads stem from the seats being cut significantly lower, but I was suprised how poorly they performed, I didn't think they'd be as bad as they were despite the seats.

With any luck I can pick them up quite a lot from here.

For a comparison here are some figures of stock 241 casting heads & some 243 castings I ported a while back, tested on the same bench, both on 4" bores:

Lift - stock 241 - ported 243
.1 - 66.0 - 73.4
.2 - 144.3 - 145.7
.3 - 201.8 - 212.6
.4 - 221.8 - 265.2
.5 - 228.8 - 303.3
.6 - 236.3 - 327.8
.7 - 237.9 - 338.6

 

This is the first time I've ever heard anything negative about AFR heads.

I'm a noob to LS engines, but I've been around older SBC for a long time and AFR has always been top notch.

 

it was said those heads had been butchered a bit. maybe one one tried to play with the work of art an AFR head is in their basement??? I had AFR heads and they were amazing in performance and to the eye. I would say an easy top pick for heads..

 

These heads have not been touched with a grinder, porting is as it left AFR, just the seats had been butchered.

If Tony has figures for the 225 heads on a 4" bore that'd be real helpfull to get a true idea of where they're at.

 

KnightEngines.

please post some pics of the stock CNC port and the port you working on so they can see they are as they left AFR thanks

 

Will do Dale, just gotta take some!
All I've got is a few after the basic tidy up - only touched up one head tho, the other is as it came off the car, I'll snap some pics before I touch it.

Looking like it'll be tomorow before I get back to them, 1 day back from my break & I'm getting hammered with trade crap again, but I'll make the time to fiddle with it a bit more.

 

There is defintley some sort of misunderstanding here. AFR has outstanding products, but what is more outstanding is the reputation,customer service backing the product, and the cut above the rest. Essentially that is what you might pay a little extra coin for. My AFR heads on my 346 I had were amazing. Tony will get this cleared up.

 

im not saying they are not great heads, we went 8.2@170 straight off the bat at a tad over 3200lb, they worked great in that setup, they are by far the best bang for buck heads you can get..

i was simply asking if anyone inderpendent has flow figures on them, so far not 1 interpendent person has posted any flow figures which is a little strange..

it may just be as KnightEngines said the difference between measuring the flow on a 4in bore not a 4.125 bore.

 

Proof that they are untouched other than valve job - which as you can see is horrible, heads have been previously bead blasted, but you can still see the CNC porting:

 

After a little work, not done yet, but getting there: