Pro Stock John

iTrader: (34)

I have never owned aftermarket head castings before, so I wonder...

1) If LS6/6.0's on a 3.900 bore can flow ~330 on a regular basis, how do we go about finding out, how much we could port the AFR castings without breaking through? Do they help the community by letting us know? I'm thinking their ported heads will flow maybe about the same as LS6 heads, so what happens if I wanted to port a set to say around 360 or 370 cfm? I'm more inclined to buy a set of raw castings and have them CNC'd by someone else... Thoughts?

2) 205 vs 225's, what is the rule of thumb when selecting them? I see that they offer like four heads for the Mustang, seems like so many choices.

Cstraub

iTrader: (1)

John,
I'm sure Rick has added material so that the port can be further developed without "hitting water". Also most head companies have what I call "peanut" port castings. All the machine work is done except the exhaust and intake ports are left unfinished except for the cast hole. This allows a CNC shop to "massage" the port to their own design. These are not generally available to the public but are sold to the CNC shops.

Chris
Stef's Performance

smokemup

iTrader: (6)

I've heard that AFR doesn't believe in water above the quench area. I wonder if the LS1 castings are like that. To me that's a big negative right there. I'll be interested to see if they have knock and/or heating problems.

I've also heard porting AFR's will be very different from the stock castings. I'm sure a good amount of trial and error will be needed.

I'm very interested in a set myself but I'm planning on sitting back and see how others run with them. I'm hoping for the best and have my fingers crossed.

Pro Stock John

iTrader: (34)

I'd like them to cut up a set and tell us what we can or cannot do them, so we don't screw up a set of heads.

smokemup

iTrader: (6)

That would be ideal. Usually the head porters keep that type of information to themselves because it cost them a lot of money to learn that information.

haole_boySS

iTrader: (1)

I posted a question about the AFR's in the GP section but I will ask in here too.
What is the valve train about. Is it all AFR components? Whats the max lift on the springs that are sold with the $2500 complete heads? Are the springs seats stock diameter? Is there a spring upgrade available? Are the retainers steel or titanium?

And I do agree with PSJ, AFR should be following what the LS1 world is doing as far as head porting/polishing etc and be ready to answer all of our questions. I also think that AFR cutting up a set of heads to tell us what we can and can't do is an Outstanding idea. I don't want to be "that" guy that gets his new heads tweaked and ends up with a pair of $2500 paper weights.

XLR8NSS

iTrader: (4)

I wonder if a C5R port could be "CNC'd" into a set of the 225's Could you imagine the airflow a turbo could put through something like that at low boost levels.

11 Bravo

iTrader: (3)

I am curious as to how the AFR 225's compare to the GM C5R heads.

99 Black Bird T/A

iTrader: (4)

Is that true AFR doesn't like water above the quench area? How well does that work with their other heads? More prone to ping?

I agree with the above comments. I think AFR should be feeding us a little more info and it would help "ripen" the market more for their new product.

I would like to know the intake runner length on the new AFR's I could do a few velocity calculations to compare their velocity with current ported LS6 heads.

BTW- my new TEA 2.5 LS6's came in today and peak flow a very high lift was ~332+ cfm on a 3.9 bore.

Chuck@

iTrader: (1)

Basically I would recommend waiting awhile before you purchase them. That way you can see what we (all the shops of LS1tech) can get out of them. I'd hope they'll flow quite a bit better than LS6's, since they should have a lot more material to work with, but who knows. Even if they only flow the same or slightly better, having the more durable castings should be a big plus for the high hp cars. I'm going to order a bunch of sets as soon as they start taking orders. And I'll post up flow numbers once we start porting.

As for the question about comparing them to C5R's... I don't see that happening. You can get C5R's flowing over 400. I'd maybe hope for about what Pro Stock John said, 360-370. But we shall see



Chuck

Black Sunshine/ 00SS

iTrader: (1)

I dont care if they produce the same power as my stage 3 ARE heads. If they allow me to spray 100-200 more HP, because of the thicker deck, then I'm all over them..

I'm patiently waiting for it all to pan out.