N4cer

iTrader: (11)

Hello? Milled how far?

silverbandit0996

iTrader: (2)

to about 61cc's.

N4cer

iTrader: (11)

Well, you're missing the point. Typically a CNC'd head has had some work done in the bowl. So before milling, it usually is a greater volume than originally. So instead of volume of combustion chamber, tell how much was milled off the head.

silverbandit0996

iTrader: (2)

it is just a stock 317 head but all i am going to get done is milling since they come whith a 70 something cc chamber.

hammertime

iTrader: (1)

the more you mill to raise the compression, the less PTV clearance you will have, which I think is what he's been trying to say.

PREDATOR-Z

No it will not fit on that much mill.

BOWTIE

In addition to this, running a thinner than stock head gasket (which will raise the compression more than the equivelant amount of milling) will also decrease the p/v clearance. I would start with the thinnest head gasket you can get away with and then follow that with a head mill if you can. If those heads are really that big to begin with, you may consider a head swap or consider flycutting so you can get the compression where you want it. This is one of the main reasons I decided to go with the 5.3 heads, they give me a 63 cc combustion chamber with out sacrificing any P/V clearance, which should give me the SCR/DCR I want with out the need for flycutting.

silverbandit0996

iTrader: (2)

oh ok. now i see where everyones coming from, i thought yall were saying i was gonna get cnc heads but these are stock 317's that im gonna get milled. what about the fm12 on a 112? could this fit, maybe with a little less milling?

PREDATOR-Z

These are not the heads you wanna use. They are ~71 cc and every .005 flat mill is a 1cc decrease. Just to get to stock 66cc, you would have to mill .025 which is acceptable but starts limiting your cam options on PTV.
If you insist on using those heads, I would mill them .040 and use a high lift LSK low duration cam with a tight LSA.
Still though, I think you should sell these to someone wanting FI application and get 243 castings.

JRracing

iTrader: (35)

That is your best bet!

silverbandit0996

iTrader: (2)

ok. well how much do you think i could sell them for. they have brand new 01 ls6 springs in them.

MightyBobo

iTrader: (12)

Not trying to hijack, but I will find out my results from my Crane setup here in the near future finally. Been swapped since late March last year - just havent tuned properly yet due to the harmonic my 832 springs had...

silverbandit0996

iTrader: (2)

would it be worth it to save and get some stage 1 243 or just get some stock ones? cause im on a really tight budget, thus being the reason i got the 317's in the first place.

silverbandit0996

iTrader: (2)

bump.