"Monk" wrote in message
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I've alway thought it would be more practical to CNC saw all the cooling
fins. Seems a bit extreme at first glance, but if you go to the time or
expense to fabricate patterns to cast the heads, we must be talk about
doing
more than just a couple of sets. So the programming cost might well be
worth
the cooling efficency of extremely detailed cooling fins.

I disagree, sand casting would be easier than milling from solid
block. Just sculpt your head out of wax cover with sand and pour your
casting. A little grinding here and there and there you have it. OK,
not that simplistic, but you get the gist.

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I didn't suggest milling from billet. Just milling the cooling fins. The
overall head with valley for the rockers, combustion chambers, ports, etc.,
should be green sand cast.

It's also not possible to green sand cast over a wax investment. Even if it
were simple enough to sculpt your heads out of wax, which it's not, you
would have to investment cast them.

Sand casting the heads and machining detail not practical with the green
sand or air set process is the only practical method for producing a limited
number of parts. Tooling cost for wax or foam investment casting would be
too prohibitive.