I am looking into a set of AFR 225's. I think they are 68cc. Anyways, I am looking all around trying to find out what determines the ideal combustion chamber size of the head for my D1 setup at max boost aka over 700rwhp. My ratio will be 9:5 and I plan on going with ls9 gaskets. I would just like to have an overall better understanding of what is optimum.

 

you guys are a wealth of knowledge lately.

 

Not sure I follow you? The AFR's come in 72 and 65cc chambers-run whatever head you want and the dish you need to get 9.5 to 1.

FWIW, you don't need much at all to make 700 rwhp-you can do that easy with just a set of stock 317 heads.

 

You waited 1 hour for a response before a smart *** comment...?

 

3.905 bore 3.622 stroke and a 68Cc with a .054 gasket will get you 9.6-1 ish 9.7-1 compression. Idk what the ls9 gaskets are thickness wise. I plan on running that for my 347 when I start building it but with a 66cc, bc I want to be right at 10.1 for my build. Like said above u don't need afr heads to make that kinda power. The head deck thickness with the 225'swill give you a piece of mind but it's not needed.

 

damn skippy. i dont have time to wait. ppl are holding up progess.

 

so why would people all be buying these nice *** heads? i mean im going to get them anyways just because of the quality and thick deck , but if people can do so on a stock 317.....then why would anyone spend the 2600 if there is no additional benefit? just for bragging rights.

 

I mean don't get me wrong afr heads are a great product and If could find a good deal on a set I would go with them too. But I wouldn't buy them new. When my time comes I'll prob run some CNC'd 243's but that's just me. The money I would save there I would use in another place. If you don't have a budget your working with then hell with it get the 225's. I'm not pro by any means but hopefully a vet will chime in and get you a lil better insite on what's your best option

 

well there is a set on here now with springs and everything for 1800 from racerbill. i would get them right now, but I have other things that have to happen first like machine shop and part and assembly....and once that happens then i will be waiting on a good set of heads and gaskets and adding a fuel pump and some fuel lines.

 

All stock casting heads have their limit. One way to get them further is to run 1/2" head studs but even then you will be prone to lifting a head or pushing a little water. I'm a little into the 800's and plan on swapping my Stage 3 LS6 heads out shortly for a pair of TFS 235's. They've done done me well up to this point but I don't want to lean on them to much harder and find their failure point. Their a great bang for the buck, but they too have their limits. A lot of how well they do comes down to the tune...