Tony Mamo @ AFR

iTrader: (13)

Hello Everyone,

Seems there is a little confusion regarding "P to V" (piston to valve clearance) when running AFR 205 cylinder heads. We get a handfull of calls on this subject as well as seeing different claims on various threads all over the internet. I wanted to take the time to clear this up once and for all.

All things equal, an AFR 205 head will provide you with an ADDITIONAL .010-.015 piston to valve clearance when compared to a stock 65-66 cc chamber LS6 casting. Assuming you mill either the 205 (which comes 66 cc's from the factory) or a factory LS6 casting to the same "lower" figure for additional compression (lets say 62 cc's for arguments sake), you will always have slightly more piston to valve with the AFR 205. The "delta" always remains the same.

The upcoming 225 head however will be a different story....considering the same 62 cc scenario, you would have approximately .020-.025 LESS "P to V" than a factory LS6 head at the same finished chamber volume of 62 cc's. By the way, while I'm on the subject, it is now "in stone" that the 225's will be offered with either 62 or 72 cc chambers from the factory....additional miiling can achieve anything smaller than 62 or a figure between the two, but no chamber volume larger than 72 will be available. Earlier information available had indicated 76 cc's, but we ultimately decided that 62 cc's and 72 cc's would cover more ground in various engine configurations. The two contributing factors regarding the 225's loss of "P to V" are the larger diameter 2.080 intake valve, and the slightly larger, more open chamber design the 225's will come equipped with complimenting the 225's different valve size and shape.

Hope this info help a few of you out....If any of you have any additional questions feel free to call me at AFR or email me direct at tony@airflowresearch.com

Regards,
Tony Mamo
AFR Sales / Product Design

FASTONE

Good to hear from you Tony,when are the 225 heads going to be ready?

Pro Stock John

iTrader: (34)

Thanks for posting.

Are you guys still doing a 76cc head?

FASTONE

By the way, while I'm on the subject, it is now "in stone" that the 225's will be offered with either 62 or 72 cc chambers from the factory....additional miiling can achieve anything smaller than 62 or a figure between the two, but no chamber volume larger than 72 will be available

Hysteria

That shouldnt be too much of a problem, just have a competent machine shop sweep the chambers out to the bore line. That should get you a couple of cc's.

pdd

iTrader: (3)

Earlier information available had indicated 76 cc's, but we ultimately decided that 62 cc's and 72 cc's would cover more ground in various engine configurations.

maddboost

iTrader: (11)

Any ETA on when the 225s are gonna be avaliable?

Reckless

iTrader: (9)

Good info Tony...thanks!

FASTONE

They should be out soon I would think,as they are based on the same casting as the 205s,and the casting process was the holdup on the 205s. I sure would like to see some flow numbers!!!!!

Tony Mamo @ AFR

iTrader: (13)

Guys...

Were getting close...Should be testing some prototypes off the CNC machines by the tail end of next week. After that its a matter of "fine tuning" and dialing in the program....lots of flowbench testing until we are completely satisfied with the finished results....this process could take a week....or it could take four weeks. It is finished when it is right. After that, "Production" gets the green light and the chips start flying. We have a very limited number of castings set aside for the first production run, so anyone that knows they are interested should contact AFR directly and get themselves on the "Pre-Order" list. The customers on that list will be contacted shortly as we approach the launch of the first production run of 225 castings.

I will be posting more about the design goals and objectives we strived so hard to achieve with the 225 program in the next few weeks....Keep an eye out for my post addressing those issues.

Thanks once again for everyone's patience....we are ALL eagerly anticipating their release.

Regards,
Tony M.

Beast96Z

iTrader: (21)

So the way I am reading this, is that if you buy a 66cc chamber AFR 205 head, then mill it .020 for 62cc's, you will only be loosing .005-.010" clearence as compared to a stock casting? I think that is how I read it. If so, that's pretty cool. You get the desiered compression without the big loss of clearence. Can't beat that. Sounds like people that are wanting to port there own need to get the "as cast" versions with the 66cc chamber.

Ben R

Thanks for the update Tony! I'll be sure to check PTV now before we fire this thing up for the first time.

Got Me SOM

iTrader: (2)

pardon my stupidity but what compression will the 72 cc chambers put my compression at? I have a stock bottom end.

I'm saving up for a set of these for my blower car, can't wait !!

PREDATOR-Z

+/- 9.0:1

Got Me SOM

iTrader: (2)

very cool thanks!

SideStep

I am afraid to ask but here goes...

Tony,

How much are the 225s going to cost approximately???

Thanks,

Spellbound

Ok, someone correct me if I am wrong, I can run my unmilled 205's with a T-Rex and have a tiny bit more ptv than with Stock heads? Any opinions on how the T-rex would run with these heads?

OWENMUSTANG

iTrader: (2)

would give slightly more room...should check anyway...just a thought.
why not a less lift and/or duration cam with higher compression?
guessing this will run better and make more power....

Spellbound

I just happen to have a "Rex" sitting on one of my garage shelfs, lol. I bought it impulsively when they first came out and later decided not to put it in because I would have had to fly cut my pistons with the heads I currently have on the car. I will prolly just leave the MMS 229/229 575/575 114 cam that I already have in the car. Thanx for the opinion.