head milling

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Looking at this more, it does seem like tkaing some off the intake side of the head would allow the intake to drop further and let the ports line up, but is there a point at which the valley will bottom out? Would there ever be enough shaved off the head surface to matter wrt to the intake to block relationship?
 
Alright, drawing this relationship up in a cad program shows me what @66fs was talking about. I like that way of lining things up way better than having to cut intake manifolds. Looks like it allows the intake to drop lower and have the ports line right up.

Thanks @66fs
 
Cuda416 said:
Alright, drawing this relationship up in a cad program shows me what @66fs was talking about. I like that way of lining things up way better than having to cut intake manifolds. Looks like it allows the intake to drop lower and have the ports line right up.

Thanks @66fs
Click to expand...

You don't need to thank me, those numbers came straight out of the Chrysler Racing manuals. I've milled 340 J heads and 273 heads (920 casting #) and their numbers are spot on, including chamber cc's. In my experience, the bottom of the intake does not come close to the block. I usually only mill heads .040 to reach minimum NHRA chamber cc's. Except /6 heads which are stand alone so there is no relationship to worry about.
 
66fs said:
You don't need to thank me, those numbers came straight out of the Chrysler Racing manuals. I've milled 340 J heads and 273 heads (920 casting #) and their numbers are spot on, including chamber cc's. In my experience, the bottom of the intake does not come close to the block. I usually only mill heads .040 to reach minimum NHRA chamber cc's. Except /6 heads which are stand alone so there is no relationship to worry about.
Click to expand...
We'll agree to disagree. Your comment made me think about the actual geometry happening and caused me to model the problem and visualize what was going on. So, yeah, thanks for pointing me in that direction.

For a long time I went by the idea that milling the heads required milling the intake. Will that work, of course, but simply milling the heads on both surfaces eliminates the need for milling every manifold that gets mated to those heads from then on. Way simpler to do it the way you mentioned.

So, just to be annoying, I'll say it again.

Thanks.
 
Ok sorry to bring up a dead horse here but I binge watched "318wullrun"'s you tube videos last night pertaining to the top end rebuild on his 77 van.
This is something I have been curious about for a while.
Now usually when I take a set of heads in for machine shop service they reface them while they have them just to make sure they ain't warped. Usually when I ask them how much they took off it's less than 10 thou.
I read all the time about having to also take off the intake side when you mill the deck surface.
Considering that most commonly used aftermarket head gaskets are thicker than the original, can't you take that difference off tye deck surface and not touch the intake manifold face?
If the original shim style ones were 0.020 and the replacements are 0.040 that means you should be able to take at least the difference off the deck surface without touching the intake side. Right? And would definitely want to as well.
 
From Larry Shepard’s book; How To Build Max Performance from small block Mopar: .010 mill on open chamber heads removed 2.08 cc. For .010 mill from head deface mill .0095 from intake side of head and .0144 from the china wall of block. Of course if you don’t mill too much you can use rtv instead of gasket and not mill china wall.
 
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