what is max ls7 head milling amount?
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what is max ls7 head milling amount? chamber is 68cc compression will be too low to be optimal w huge cam.
they are already milled 0.030”.
how much more can i go and what is the limiting factor? it’s NA and heads are max ported. titanium valves and chambers are finished.
will be using Fast or MSD intake. if that helps the alignment issues. using Jesel valvetrain. thanks!!
they are already milled 0.030”.
how much more can i go and what is the limiting factor? it’s NA and heads are max ported. titanium valves and chambers are finished.
will be using Fast or MSD intake. if that helps the alignment issues. using Jesel valvetrain. thanks!!
You can mill down to the valve seat, but you’ll have to make other adjustments as well for it to fit. The dowel holes may need to be plunge cut deeper, manifold flanges will need to be milled, etc etc etc.
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KCS, is there an amount i can go more than the current 30 thou that will still fit by rule of thumb? i want to avoid the misfit issues and also potential valve shrouding. sorry for the noob questions. these heads are awesome but 11:1 ain’t gonna cut it. pistons are flat top w cutouts.
People have cut down ls7’s to the 50’s cc to get to 14:1. It is doable, but there are intake fitment considerations that aren’t well defined. I’m trying to get a good answer on it as well, but will likely just look to my machine shop to do it correctly. The intake flange of the cylinder head just needs to be milled accordingly.
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spanks13 thanks for the info.
I'll go out and look at how bad it lines up already at 0.030 mill amount and then see how much worse its going to get by using no gasket and try to bolt it up. That's a head gasket thickness worth of stock removal.. if its going to line up horrible I'll find out! seem reasonable?
I'll go out and look at how bad it lines up already at 0.030 mill amount and then see how much worse its going to get by using no gasket and try to bolt it up. That's a head gasket thickness worth of stock removal.. if its going to line up horrible I'll find out! seem reasonable?
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People have cut down ls7’s to the 50’s cc to get to 14:1. It is doable, but there are intake fitment considerations that aren’t well defined. I’m trying to get a good answer on it as well, but will likely just look to my machine shop to do it correctly. The intake flange of the cylinder head just needs to be milled accordingly.
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Verdad Gallardo My 4.130" bore LS7 build is using flat top Mahle pistons with 2.5 cc valve reliefs. With the Mahle pistons, 70cc heads is right at 11.8:1 at .040" quench.
My heads are at 68cc right now. I want to take another 8cc off. My heads have been cut .010-020 already. 8cc would be another ~.050".
I'd like to be at ~13.25:1 with flat tops. I wish Mahle made a powerpak piston with a small dome..5-6cc is all I wanted. I got a screamin deal on the shelf 4.130 pistons on sale + $100 rebate via ebay sale. Can't complain.
At some point the alignment will become an issue and also the manifold gaskets may start having issues as the ports become further apart as you mill down. On C6 Corvette if you run an MSD, many times you have to shave the water pump for things to fit (like 102TB) this is probably worse if head is shaved a lot. Also the GM head is not known for deck thickness and at some point I would think you would begin to jeapordize the deck strength/sealing and of course the reason for shaving is to increase compression which further enhances the issue.
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LS7 w Diamond Pistons
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Probably, but when we started there were smaller chambers with the crazy heads.. since those heads are wacky and the Jesel valvetrain stands wouldn't line up even after tons of fitting and machining, back to factory LS7 heads and new Jesel stands.
So, A - with these flat ops and cutouts I'm toast on compression and B. I'm already maxed out on the 0.030" mill if I use a thin gasket.
need to find out the piston height and cc.
So, A - with these flat ops and cutouts I'm toast on compression and B. I'm already maxed out on the 0.030" mill if I use a thin gasket.
need to find out the piston height and cc.
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At some point the alignment will become an issue and also the manifold gaskets may start having issues as the ports become further apart as you mill down. On C6 Corvette if you run an MSD, many times you have to shave the water pump for things to fit (like 102TB) this is probably worse if head is shaved a lot. Also the GM head is not known for deck thickness and at some point I would think you would begin to jeapordize the deck strength/sealing and of course the reason for shaving is to increase compression which further enhances the issue.
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Ok those are 'angle milled' to achieve 51cc chambers. That is perfect however, what did that do to the fit of the rockers? to the fit of the intake? port alignment?
It was such a major pain before when stuff didn't line up, especially the rocker stands and intake manifold. but those were 0.5" raised port heads.. so I'm not sure what this angle mill will do to everything, but it seems the only way to go to get the CR in the 12.5:1 or more range.
It was such a major pain before when stuff didn't line up, especially the rocker stands and intake manifold. but those were 0.5" raised port heads.. so I'm not sure what this angle mill will do to everything, but it seems the only way to go to get the CR in the 12.5:1 or more range.
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IIRC, you can only angle mill a fresh set of heads. I believe they start with a .010" flat cut and then begin to start the "angle" process. WCCH is the only company that I know does that kind of head work. LS7 rockers are pedestal mounted. Milling won't affect the rockers. I can not say how the intake alignment is affected with the angle milling, as I have never messed with heads that have had that work done to them. I would contact WCCH is that's a route you want to pursue.
Ok those are 'angle milled' to achieve 51cc chambers. That is perfect however, what did that do to the fit of the rockers? to the fit of the intake? port alignment?
It was such a major pain before when stuff didn't line up, especially the rocker stands and intake manifold. but those were 0.5" raised port heads.. so I'm not sure what this angle mill will do to everything, but it seems the only way to go to get the CR in the 12.5:1 or more range.
It was such a major pain before when stuff didn't line up, especially the rocker stands and intake manifold. but those were 0.5" raised port heads.. so I'm not sure what this angle mill will do to everything, but it seems the only way to go to get the CR in the 12.5:1 or more range.