garagedweller2

In BBCs and SBCs, which will flow better?

QuickVet

I have heard that the flow rating on AFR heads is :bs

I think im going to go with Dart when I get the cash

81vette

Click on the link below. At the bottom of the page are the flow numbers for most of the heads you'd likely to be interested in.
http://www.chevyhiperformance.com/techarticles/41598/

From the Chevy Hi Performance website: "The idea behind this effort was to use one flow bench to test as many small-block and big-block Chevy cylinder heads as possible. By using one flow bench and the same test procedure, we eliminated many of the variables that exist between different benches and operators. All the tests were performed at Westech Performance Group by John Baechtel and Steve Brule using a SuperFlow 600 computerized flow bench. We tested each head not only for intake and exhaust flow at 28 inches of water, but also measured each combustion chamber and intake port for actual volume."

mark


[Modified by 81vette, 7:44 PM 1/18/2003]

'79ProwlerOrange

Damn! AFR195s wernt tested. thats what i was aiming for.

81vette

I think their links may be messed up. Click on the Category 3 link. The 190 AFR's are there, and they about the same as the 195's. I think the difference is the 195 is designed for a Victor Jr. type intake.

mark

A C

Make sure you compare apples to apples. You have to compare the same runner size and also if one head is a CNC'ed head, the other one should be too. I know Brodix now offers a CNC line.

AC

'79ProwlerOrange

sweet. im sticking with my decisions for AFRs. :smash:

garagedweller2

Sorry!
That was 2 questions (or 1 with 2 parts)
In Small Blocks, which flow better?
In Big Blocks, which flow better?

jerryjfunk

"I have heard that the flow rating on AFR heads is :bs "

Did you hear that from Brodix? :lol:

Jerry

Pete79L82

Looking only at flow numbers is not a good way to predict the performance of a cylinder head. Port shape, floor to bowl transitions, bowl shape, combustion chamber design and plug location all play a huge role in how well a cylinder head will perform. Just making a port big to show "big" numbers on a flow bench without having good port design will slow the air volocity and cause fuel/air seperation in the runners drastically hurting performance.

My opinions are directed at small blocks because my hands on experience is building them about 50-1 to big blocks.


AFR are a fine cylinder for the street and for the money. But they are not in the same league as a Brodix or Dart Pro-series or Race series. And the cylinder heads are priced accordingly.


Brodix and Dart have a much better floor and short wall design over comprable AFR heads. This help keep air/fuel suspension at its peak. They also have a better chamber design over AFR promoting a better flame front and full fuel burn.

There is no one cylinder head that is the "best" for all applications. The best cylinder head choice is one that will give you the air flow CFM required for your application with the smallest runner volume. This will result in the best power curve and drivability.

For the street AFR would be a good choice of price/performance. For maximum performance/HP I would have to go Brodix or Dart.


[Modified by Pete79L82, 8:12 AM 1/19/2003]

QuickVet

sorry, every engine builder I have talked to told me this.

SmokedTires

I"m hoping the Brodix Track 1's are good, I just bought a set of fully ported babies :D ! Technology has improved over time, so any of the aftermarket heads should be an improvement over stock :yesnod: . Even my present Sportsman II's are suppose to out flow ported stock heads when they arrived in cast form ;) .

garagedweller2

thanks! just what I needed :cheers:

jerryjfunk

"sorry, every engine builder I have talked to told me this."

I wasn't doubting you, it was just a joke. :)

Anywho, I've heard a lot of good about AFR's, especially the 180cc.

Jerry

garagedweller2

The AFR is a good street head, the Brodix is among the best, but costs more(?)