Do today's aluminum heads follow the standard BBC head where the valves are splayed and such? Just curious.

Also, does anyone know a good site for flow numbers, for stock BBC heads and today's aluminum? I'm aware of how well aluminums flow now, but just curious still. Thanks.

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Kirk

soccerguy, I had a very reputable head porter that flow doesn't mean much when trying to evaluate how well a particular head will run. His exact words were " flow don't mean *****". So when thinking about a new set of heads get them from someone who is willing to do some additional work on them and pay the difference. If you buy a set out of the box they will likely only give you a tenth or two. The "CNC" type heads will provide the most results. If you can't afford these stay with the factory aluminum ones or the small AFRs. (305cc with the CNC chamber option).

Careful Harold, we've all seen what happened to "Junior" for using that nasty "S" word. :D

Originally posted by soccerguy045:
Do today's aluminum heads follow the standard BBC head where the valves are splayed and such? Just curious.

Also, does anyone know a good site for flow numbers, for stock BBC heads and today's aluminum? I'm aware of how well aluminums flow now, but just curious still. Thanks. Pretty much for the "bolt on ones" like AFR, Brodix Canfield etc.
The Brodix Race Rites are an excellent oval with the exhaust port in the stock location.
The AFR is Rect & the ex is raised .375".
They have an oval in the works but I wouldn't look for it before the middle of next year at best.
The rest of the Brodix & the Canfields are raised .600"

Flow is not everything but it is very important in my opinion & is about the only way you can compare heads of the same general type in the real world.

The statement "flow don't mean **** does not apply to the heads we are referring to here it starts being more applicable when you get into full on race heads where size & shape are almost everything but I can just about guarantee they are still checking to see if alterations hurt flow before it hits the dyno & track for the final analysis ;)

Problem lies in the fact that you need to get the numbers from the same bench & even then you need to be very careful of who is paying for the test :D

I can tell you both AFR & Brodix numbers are very honest with Brodix actually being on the conservative side at times.

The size & shapes of the ports & chambers are probably as important if not more important than the flow numbers but in general the smallest port that will flow what the engine wants is going to be the best head. It will make more torque over a wider range even though the larger head may make slightly more HP.

Above all do not get all excited about .600+ flow numbers when you are running a .550 lift cam,,, pay attention to the low & mid lift numbers, especially for milder combos.

In my opinion, AFR has some of the best out of the box heads out there & until Brodix came out with the Race Rite series were the head to beat.

The small block 200cc Race Rite will outflow the AFR 210 to about .500 lift with the CNC chamber option & this is on my bench not some questionable advertised numbers.
;)

Mike,
I have mildly worked on 063 heads on my .040 over 402 (read 410)what kind of performance gain would I get going to a set of aluminum AFR's or Brodix?

Regards,

Originally posted by USFATL:
Mike,
I have mildly worked on 063 heads on my .040 over 402 (read 410)what kind of performance gain would I get going to a set of aluminum AFR's or Brodix?

Regards, =
Really hard question to answer but I would say they are capable of 50+ HP assuming the same compression.
I have never done an honest back to back comparison so I am kinda "shootin from the hip" here ;)

Brodix claims an 80P gain over stock heads & Brodix is usually reasonably conservative in quoting numbers including flow numbers.
You can check them out here:
RaceRite (http://brodix.com/rr_bb_o.html)

The AFR 305 although an outstanding head & definitly capable of more power I think would be a little big for a mild 402 & the oval will not be available in the foreseable future.

i too have never put much stock in "flow numbers". i would be really interested in someone actually backing up the "flow numbers" with actual dyno or on track performance tests. say like this head flows such and such and this head flows 20cfm more, then actually doing back to back testing on the same flowbench and the same dyno. and not sponsored by Bill Mitchel or any other cylinder head manufacturer or distributor. meaning completely unbiased.

Seems there used to be another guy the frequented this board that said the same thing as Mike and Harold...hmmm, what was his name? ;) flow benches don't mean doodoo and smallports=velocity is where its at....sure wish I could remember his name :D

Originally posted by Rapid Robert:
Seems there used to be another guy the frequented this board that said the same thing as Mike and Harold...hmmm, what was his name? ;) flow benches don't mean doodoo and smallports=velocity is where its at....sure wish I could remember his name :D =
Robert,
That ain't exactly what I said ;)

Our change over to a good set of Dart 335 CNC heads netted us about 3 tenths & 4 MPH on my sons 482 cu. in. Big Block powered, 3550 pound Chevelle. I think the flow does matter but how much is debatable without the velocity knowledge that is always missing. Only thing thats for sure is that testing and working on a combination, constantly, will make it faster.

You mean Ed by chance??

pdq67