Milling AFR Heads
08-21-2004, 10:44 AM
#6
I was hoping that AFR could weld the chambers before they put the valve seats in and heat treat the heads or file the core box so there has to be no milling done to reach the correct compression ratio. I'll be calling around and trying to find out if it's possible for them to do that or not.
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08-21-2004, 11:59 AM
#9
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I'm really starting to question the current AFR offering. You can run a big cam with low CR, or a small cam with good CR. I realize there is more to it than this, but the AFR set up will be hard pressed to outperform current less expensive options.
08-21-2004, 12:08 PM
#10
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Well the castings are LS1/6 targeted but with bigger valves so it is just a matter of checking if you would have enough PV or need custom pistons as we know you can only flycut so far.
Best bet get in touch with TONY MAMO at AFR, he is very helpfull as he has been to me.
Best bet get in touch with TONY MAMO at AFR, he is very helpfull as he has been to me.
08-21-2004, 01:57 PM
#12
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Originally Posted by DaleMX
Man, with that much milling I would think that the intake would be a bit of a problem. Dont do it, sell the heads and get some 5.3's.
he already has 5.3's, just asking questions and thinking about AFR's.
08-21-2004, 08:02 PM
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You may need shorter pushrods and I wonder how well the intake fits when the AFR heads are shaved that much. Lets see what CC the Lingenfelter/Edelbrock heads will yield. I hope they are not 66cc & 10.25.
I have also been wringing my hands about my "little" c1 cam & P/V issues w/ the AFR's shaved to 60cc or (whatever will give me 11:1).
Not to mention comprimised valvetrain geometrics.
I have also been wringing my hands about my "little" c1 cam & P/V issues w/ the AFR's shaved to 60cc or (whatever will give me 11:1).
Not to mention comprimised valvetrain geometrics.
08-21-2004, 08:38 PM
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Originally Posted by PREDATOR-Z
You are he already has 5.3's, just asking questions and thinking about AFR's.
he already has 5.3's, just asking questions and thinking about AFR's.Dale
08-21-2004, 11:20 PM
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I keep reading these threads, observing issues arise with AFR heads and CR vs PtV and such. The only reason I'd run AFR's over a well ported LS6 head would be FI, as then you can run the low compression with a hella big cam, have all the deck strength you want, still reap the benefits of the AFR castings, and don't run into issues with having to mill them. 
I just hope Edlebrock gets off their *** and introduces their head fast enough to help lower the prices of LS6 castings in the first half of '05, which is when I'll be in the market for some.
I just hope Edlebrock gets off their *** and introduces their head fast enough to help lower the prices of LS6 castings in the first half of '05, which is when I'll be in the market for some.
08-22-2004, 09:13 AM
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AFR's stock are better than my stock heads but the best "dyno tested" AFR numbers came with the heads milled .24-.55 with "smaller" cams simply because that is what fit at that point.
I do not know how well & long things line up and run & fit with the valvetrain geometry all skrewed up at that point anyway. I do not want to guess at my compression or P/V either. I was "hours" from calling up and trying to order these heads. Now I may wait for the Edlebrocks...I'll be at SEMA and I will talk to them.
I do not know how well & long things line up and run & fit with the valvetrain geometry all skrewed up at that point anyway. I do not want to guess at my compression or P/V either. I was "hours" from calling up and trying to order these heads. Now I may wait for the Edlebrocks...I'll be at SEMA and I will talk to them.
08-22-2004, 04:38 PM
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Originally Posted by PREDATOR-Z
That is one of the reasons I bought them, but in a gaseous form N20 
08-22-2004, 07:17 PM
#20
AFR's / Milling Info... Hello everyone...
I posted this in another thread....For the benefit of those who might never see it, I wanted to copy and paste it here as well.
Hello...
Seems everyone is panicking about smaller combustion chambers, how much can I mill?.....etc....etc.
First off, you are no worse off from a "piston to valve" standpoint with an AFR 205 head versus a ported stock head....in fact, you are probably slightly better off as a similar chamber volume from us should yield slightly more piston to valve.
That being said, to not consider an AFR because we don't offer a smaller chamber "out of the box" is silly....Let us or your favorite machine shop mill the heads. We do it all the time.
Also, you guys don't realize that you just can't take a head that has a certain "valve drop", and just start arbitrarily welding aluminum everywhere to shrink the chamber volume while still retaining the same "valve drop" which directly effects piston to valve.
(NOTE: When I say "valve drop", I'm referring to the distance the valve will drop if you placed the head on a flat surface. You can check that figure with a checking spring by pushing down on the valve until it contacts that flat surface. Chamber design, milling, and valve job heights are the three variables that directly effect valve drop which directly effects the amount of piston to valve available.)
Actually, you COULD weld aluminum everywhere and pick up some compression by shrinking the chamber, and you can also completely destroy all the low and midlift flow numbers as well with a new "chamber design" that shrouds the valves with a bunch of extra aluminum. Final result....an engine that makes less power with higher compression because it can't fill the cylinder as well. There is a method to our madness....we have been CNC porting and manufacturing cylinder heads for over 30 years!!
The AFR chamber design was held as small as possible while still complimenting and aiding airflow all across the curve. It is more of a "semi-open" design with dual quench pads while I would say the factory design is more of an open "bathtub" style chamber.
Feel free to mill as much off the deck as needed....it's .750 thick. There will be a point with an excessive mill that correcting the intake flange becomes required, but that is not an uncommon situation. Currently, the smallest we have gone is 59 cc's (approx. an .040 flatmill) and manifold fitment is still not an issue....Some of our dealers order and stock them on their shelf exactly that spec.
Anyway....Before spending countless days looking for info on the internet, isn't it faster and more reliable just to call the manufacturer and get their input....Thats what I do when I need some straight answers.
CALL US....I try to be available to everyone, and in the event I can't be reached, any one of our tech guys could help you. In the event they don't have the answer, they will get the answer and call you back.
Hope this helps guys...
Tony M.
I posted this in another thread....For the benefit of those who might never see it, I wanted to copy and paste it here as well.
Hello...
Seems everyone is panicking about smaller combustion chambers, how much can I mill?.....etc....etc.
First off, you are no worse off from a "piston to valve" standpoint with an AFR 205 head versus a ported stock head....in fact, you are probably slightly better off as a similar chamber volume from us should yield slightly more piston to valve.
That being said, to not consider an AFR because we don't offer a smaller chamber "out of the box" is silly....Let us or your favorite machine shop mill the heads. We do it all the time.
Also, you guys don't realize that you just can't take a head that has a certain "valve drop", and just start arbitrarily welding aluminum everywhere to shrink the chamber volume while still retaining the same "valve drop" which directly effects piston to valve.
(NOTE: When I say "valve drop", I'm referring to the distance the valve will drop if you placed the head on a flat surface. You can check that figure with a checking spring by pushing down on the valve until it contacts that flat surface. Chamber design, milling, and valve job heights are the three variables that directly effect valve drop which directly effects the amount of piston to valve available.)
Actually, you COULD weld aluminum everywhere and pick up some compression by shrinking the chamber, and you can also completely destroy all the low and midlift flow numbers as well with a new "chamber design" that shrouds the valves with a bunch of extra aluminum. Final result....an engine that makes less power with higher compression because it can't fill the cylinder as well. There is a method to our madness....we have been CNC porting and manufacturing cylinder heads for over 30 years!!
The AFR chamber design was held as small as possible while still complimenting and aiding airflow all across the curve. It is more of a "semi-open" design with dual quench pads while I would say the factory design is more of an open "bathtub" style chamber.
Feel free to mill as much off the deck as needed....it's .750 thick. There will be a point with an excessive mill that correcting the intake flange becomes required, but that is not an uncommon situation. Currently, the smallest we have gone is 59 cc's (approx. an .040 flatmill) and manifold fitment is still not an issue....Some of our dealers order and stock them on their shelf exactly that spec.
Anyway....Before spending countless days looking for info on the internet, isn't it faster and more reliable just to call the manufacturer and get their input....Thats what I do when I need some straight answers.
CALL US....I try to be available to everyone, and in the event I can't be reached, any one of our tech guys could help you. In the event they don't have the answer, they will get the answer and call you back.
Hope this helps guys...
Tony M.
