317 heads
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From: Long Island, NY
317 heads how far can you mill these heads to? i believe i need to get them to a 59cc to achieve my desired compression ratio. is this possible? also is 11.5 to 1 safe to run on 93 octane without worrying about detonation?
That's going to be a good amount of milling. Coming from 72cc to 59cc. Ballpark .006-.007 per cc that is going to be .090". I don't know that you'll be able to get that far without messing up the geometry. I have seen heads milled .050+ without a problem but .090 is a lot. You would probably be better off looking for a different piston or starting with a LS6 heads (64cc). Just food for thought.
Jon
Jon
Jon
Jon
You won't be able to go that far, at most you don't wan to mill more than .030 off the deck if you thinking of going with any type of FI the head won't hold it. Now N/A you can and I have seen people go as far as .045 - .050 but anything further than that you are messing with the structural make up of the deck. Anything can happen and it won't be pretty.
Back in the day, guys were welding up the chambers on 317 heads, CNC a chamber and port, make 317 heads 60cc chamber. This was back in old school LS1tech era.
Since 243 heads came out, no reason to weld up GM castings to make small chamber heads.
Since 243 heads came out, no reason to weld up GM castings to make small chamber heads.
Thread Starter
TECH Enthusiast
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Joined: Sep 2008
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From: Long Island, NY
ik i could get my hands on a set of 241s by tm. do you think its worth me picking up them and having my engine builder port and mill them to 59cc? how much could these heads flow and would it be benefitial to my 383 build? trying to get my car done in a week so trying to do this in a hurry.
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ik i could get my hands on a set of 241s by tm. do you think its worth me picking up them and having my engine builder port and mill them to 59cc? how much could these heads flow and would it be benefitial to my 383 build? trying to get my car done in a week so trying to do this in a hurry.
before i forget see if you can pick up a set of light weight valves (ls6), it will give you great stability in the upper RPM range specially after 6500 rpm. also stick with the stock rockers they will give you the best valve train geometry.
Last edited by 02*C5; Jul 30, 2010 at 12:10 AM.
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