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

 

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.

 

^ Patriot used to do it with 039 castings. I had a set for a while until they got stolen.

 

how did that happen i know there is a back story to this

 

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.

 

everyone that has had 241 casting eventually go to a 243/799 just because of the flow capabilities of the 243/799. You can easily go down to 59CC chambers I had a set but you will outgrow the capability of a 241 quicker than you will a 243/799. I have seen guys running 600+ hp cars with slightly massaged 243/799 heads. I you would wait you can pick up a set of 243/799 which are the same head different casting number and then go just my .02

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.

 

There's actually not and it wasn't amusing. Someone broke into my friend's old shop and stole a bunch of parts, tools, and car keys. The police never found out who it was and we were all SOL.