CLIFFRSRAMAIR

I just flowed my 225 cnc AFR heads today. I pulled one head out of the box and brought it to our machine shop. I am not happy with the results. They were flowed on a Super flow - 600 @ 28 water and 4.125 bore. Temp was 74 degrees at 3:00pm

cfm intake exhaust
200 130 108
300 192 159
400 246 200
500 284 219
600 313 227
700 335 233

The exhaust was flowed without a pipe. These numbers are much lower then AFR's advertised numbers. I was wondering if anyone else has had lower flow numbers? I can understand and except 1 to 3 cfm difference between flow benches but not 7 cfms at 600 on the intake and 23 cfm's on the exhaust side.

LIL SS

iTrader: (9)

You can't compare the exhaust IMHO.. Apples and Oranges..

I'm assuming the intake was not on the head when flowed?

CLIFFRSRAMAIR

No, the intake was not on the head when flowed. I understand AFR used a 1 7/8 pipe when they flowed there heads. I have a 3 inch straight 1 7/8 in pipe and 15 to 16 cfm is the average improvements. This still falls short of 250 cfm at 600. By the way I do think these heads are very nicely CNC'd and I am impressed with how they look but I am more concerned with results then looks!

Beast96Z

iTrader: (21)

7 cfm isn't bad. In fact, I'd say it would fall into the "normal" catagory. Lots of things can factor into how the head flows on a diffrent bench. Air density, humidity, temperature, placement of the head on the bench, and so on can all cause variations. Tony from AFR made a statement that the AFR heads are designed to work with the pipe in place on the exaust. They don't focus on flow without a pipe in place. If the head is ported for the pipe, then flow without the pipe could suffer alot. I wouldn't worry about it at all. If you want the numbers to pick up, flow the head when it is colder and deffinatlly put the pipe on the exaust.

Tony Mamo @ AFR

iTrader: (13)

Actually your flow results look different then any 225 I have flowtested in the past....Our 225's do not continue to climb on the intake side till .700 as your results seem to indicate....most will peak around .600 to .630 valve lift, but none of the 225's I have tested will pull cleanly to .700 (they were designed to be more effective in the .200-.600 range and still have only a moderate cross sectional area....few LS heads will pull clean to .700 and the ones that do are much larger (typically) and might have steeper seat angles to enhance peak numbers). ANYWAY...that leads me to somewhat question your results (what bench, what bore size, clay or radius entry, what flow tube.....yada yada). If your questioning what you purchased feel free to call me at AFR so I might be able to better help you over the phone and possibly arrange the freight back to us so we can evaluate the cylinder heads....to be very honest with you, I would be VERY surprised if your heads dont flow what we advertise (or extremely close)....I have been personally spot flowing alot of the 225's that are leaving our door, and they have all been right at advertised (within a few CFM's) and some better (322-324 @ .600). While it is certainly possible there might be a problem with your heads, based on what I have been seeing (and hearing elsewhere) I think it is far less likely that is the case.

Please contact me at AFR and we can discuss it...

Thanks,
Tony M.
(818)890-0616 Ext. 109

PS....Milling the cylinder heads for higher CR will also effect the flow numbers....just an FYI.

CLIFFRSRAMAIR

Thanks for your insight as it's very important to me. I did have the intake radius clayed which will pick up the top numbers and for that matter all the flow numbers. I have seen 3 sets of 225 AFR heads and all of them have radius cut seats. The bench we use dose not like radius cut seats and will decrease flow numbers. The air moving through your heads was clean and smooth without "popping" or "cracking" sounds which is impressive. Yes, they did flow to 700 cfm's and very smooth at that. I did lightly blend the seats on the short turn and bowl, both intakes and exhausts on one head to see if it made a difference. This increased the flow numbers from 200cfm's to 700cfm's by 3 cfm's across the board. I think these are great heads form what I have seen and other people are saying or I would not have purchased them. I just was suprised by lower numbers when I had them flowed. Again thanks for your information.

TJ

iTrader: (10)

its great to see the people that sell the product actually trying to help you out.
thumbs up to AFR.