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The .030" offset provides the same distance from the cylinder wall as a 4.125" bore... .030" which helps a lot.
4.125" is .060" larger than the 4.065" bore... half of that is .030" (radius) in case you're wondering how I came up with that (and assuming the head remains centered).
The 4.185" bore I'm aiming for provides .060" of valve to wall clearance above an LS3 bore.
The difference between a 4.03" and 4.065" bore is .0175" so you can see how that helps. Nearly doubling it would help even more.
I don't know how that affects the manifold and such with clearance. But .030" isn't a lot.
I will ask my builder about this too and see what he says.
The 37900 Moroso dowels move the head .030”
Again, they are designed for big block Chevy, but fit LS applications exact. If shrouding is an issue, this is an easy fix. Moves the exhaust valve over toward the wall like an ls7 head also, but exhaust shrouding isn’t an issue since piston is forcing pressure outward. I’ve used these and it works well. No issues with manifold alignment upstairs either. There is more than .030” play in the manifold bolt sleeves. Run it by your builder.
The 37900 Moroso dowels move the head .030”
Again, they are designed for big block Chevy, but fit LS applications exact. If shrouding is an issue, this is an easy fix. Moves the exhaust valve over toward the wall like an ls7 head also, but exhaust shrouding isn’t an issue since piston is forcing pressure outward. I’ve used these and it works well. No issues with manifold alignment upstairs either. There is more than .030” play in the manifold bolt sleeves. Run it by your builder.
Edit...
make sure to check radial clearance on your pistons valve pockets with modeling clay, while checking ptv, if your running pockets. I cut my own pockets, so I had no problems.
Edit...
make sure to check radial clearance on your pistons valve pockets with modeling clay, while checking ptv, if your running pockets. I cut my own pockets, so I had no problems.
I may screen shot this and send to my machine shop. May do this next go around even though I have a 4.125 bore
Decided to go 408 LS2 after getting a decent deal on a slightly used unblemished 4 inch Callies CompStar Crank. The build is still a long ways off but the crank is on the way.
Decided to go 408 LS2 after getting a decent deal on a slightly used unblemished 4 inch Callies CompStar Crank. The build is still a long ways off but the crank is on the way.
Decided to go 408 LS2 after getting a decent deal on a slightly used unblemished 4 inch Callies CompStar Crank. The build is still a long ways off but the crank is on the way.
Tusky, The set of reworked GMPP 243's I used for flow testing the various intake manifolds. They have a new revised midlift valve job, new intake and exhaust valves. 250cc runners, 2.04 intake valve, etc BTR platinum springs. Peak intake ~ 303cfm ~239 exhaust. We hit ~335cfm testing high lift vj but it's a daily not a racer so I picked the mid lift for thr fatter mid range.
I can't find the exhaust flow numbers this morning.. Lol..Mamo ported 102 LSXR intake manifold. Not perfect heads but budget friendly since I have them.
SF1020, 4 inch bore, @28"
Last edited by 99 Black Bird T/A; 06-26-2019 at 05:48 AM.
Tusky, The set of reworked GMPP 243's I used for flow testing the various intake manifolds. They have a new revised midlift valve job, new intake and exhaust valves. 250cc runners, 2.04 intake valve, etc BTR platinum springs. Peak intake ~ 303cfm ~239 exhaust. I can find my flow numbers thus morning.. Lol..Mamo ported 102 LSXR intake manifold. Not perfect heads but budget friendly since I have them.
I think you going with a great head thats go make more power than you expect. Any camshafts in mind ?
Brotus, You go will surprised to see your 40X ci motor dont make much more power than my LS3 headed stock bottom end LS2 setup with the BTR 229/244 cam. I say this cause MOST 40X CI LS3 headed motors fail on the dyno and at the track as well.... but thats none my business.
Brotus, You go will surprised to see your 40X ci motor dont make much more power than my LS3 headed stock bottom end LS2 setup with the BTR 229/244 cam. I say this cause MOST 40X CI LS3 headed motors fail on the dyno and at the track as well.... but thats none my business.
Agiain Wade, you made great choice brother.
Lol.
If it doesn't I will get you to rebuild my engine to your specs.
06-09-2019, 04:24 PM
