The upper section would also have to have the rocker shaft stands as well as oiling passage(s) and the mounting surface for the valve cover. While the two-piece idea may just have merit, let's not over-simplify it.

As for sealing....perhaps a groove cut into the sealing surfaces for o-ring type rubber? The stuff can be had from McMaster-Carr, and I'm sure other sources. Cut to fit where needed, a dab of silicone where the ends meet, and bolt down the top section.
One may have to use something a bit better for the intake ports.

Roger

It has been done before. Using a cast billet for a CNC head
is a good idea. Casting technology is now lots better than the
1960s high volume green sand production that Chrysler used.
Starting with a casting that looks like a head is a good approach
for saving costs as a big chunk of alloy is expensive, but scrap
from junked heads is cheap.

I don't know of any hobby foundries that have attempted
35 pound castings. Lost foam can be used for the water
cores as foam generally works well for long and narrow
castings. That's because the narrower castings have less
concentrated heat, which would vaporize the foam too
rapidly on a thicker casting. Foam is very accurate, you
can often see a pebble grain in the finished casting.

Patterns are traditionally made of wood, but you can use
plastics, fiberglass or even clay for a prototype pattern.
You can use a slant six head with stuff glued to it as a
one-off pattern.

The ports can be milled from the shaped casting. Some
low volume compromise, one way or the other is probably
practical. Getting a competent CNC machinist would open
up possibilities.

The deck might be a milled steel semi-permanent mold.
Lots of possibilities with a CNC machine. It could only be
a labor of live, that's for sure. Once the kinks are ironed
out a few of these might be produced a month in a small
shop.

Why not? It's been used to put together sections of a 5.7 head to make it fit a Slant.

_________________
Official Cookie and Mater Tormentor.

Doug's split OEM head would be useful in making a pattern
for a stock head, maybe with changes like revised combustion
chambers or raised intake ports. Thanks Doug for that.

I looked at some hobby casting sites and found some
interesting projects, but none so large as a head. People
cast water pumps and working 1 cylinder motors, scale
models of flat head Ford V8s and so forth. An amateur
with a couple of helpers could do a /6 head if they had
great patience and a willingness to start over again.

But there is plenty of collective wisdom so that if you
followed a proven path you would get good results
without the headaches, but it would take a long time
regardless. Once a set of prototype patterns were
improved you could send these out to a production
foundry.

When I was very young my father worked on his
cars. I saw the sand grain pattern in the castings
and knew how these were made. With the parting
lines, I could see where the cope and drag came to
together. Because we could very carefully place
the cores, an amateur casting might even be better
than high volume castings from the 1960s.

Craftsmen were not employed for production foundry
work, workers did only what they were trained to do.
Workers roles are deconstructed so that they do one
task repeatedly. It is not uncommon for a entire
production run to go to the scrap bin as everyone
was just doing their job. A hobby shop could
tweak the low buck process to achieve high quality,
but at very low numbers.

Smart man...
This "cut" was done to answer head casting questions.
What we see here is what the "cope & drag" pattern and corrosponding mold halves would look like... less the draft, shrink and all the other changes needed for a "next gen" cylinder head casting.

The facts remain... cylinder head sand casting are the most challenging castings out there, mostly due to the water jackets.

This view of "inside the SL6 head" helps me visualize how the upper and lower water jacket cores were done (by the factory) and how they could be layed-out in an after-market head.
DD

Hello,
I think I may have posted this link before,but there is some interesting stuff in it about the mold and production process with alloy.in particular this bit
Pity their interest did'nt lie with Mopar.

regards,CRM

Thanks for posting these links. This is exactly the kind of information to promote better understanding of the challenges of alloy heads and blocks.

Those patterns are works of art.

_________________
Yeah....Im the one who destroyed this rare, vintage automobile.....

I've found some serious hobby casters who can pour 80 pounds of
aluminum in a home shop using a home made furnace.

A difficulty for a longer casting like a head is the metal would cool so
rapidly (and begin to shrink) that one person could probably not pour
the metal fast enough. You'd want a helper to assisting in pouring simultaneously.

The lost foam technique would work for the water jackets but you have
to hurry up and pour quickly. With a helper it can be done. Uneven
cooling would cause shrinkage and the foam would flame out before
you finished pouring. Some large risers would be needed to control
shrinkage.

Once you perfected the patterns and technique it would be smart
to farm out production castings, but you can prototype in a home
foundry. Texas State University in San Marcos has a good
foundry program which I may want to pursue. It is common to
use a home made waste oil burner to melt in a furnace to keep
the costs down ( used motor oil ).

Wait till you see my sheet metal head.....with billet chambers welded into a CNC 1" deck. Adding tube ports and rocker stands and water jackets is just like a sheet metal intake. I suppose you could just use 5.7 hemi chambers and rockers and weld up some Firedome Valve covers...oh........wait

It would cost like the Healy block.......

_________________
Yeah....Im the one who destroyed this rare, vintage automobile.....

My glass is always half full! Unless it is very good ale then eveything is off!

_________________
66 Lil' Red Piggie Valiant (Mater Crusher) - Thanks Zilla!!!!! 72 Demon (Number 1 Son's)

Gee, that's unfortunate; it's much harder for an optimist than a pessimist to be pleasantly surprised!

_________________
一期一会
Too many people who were born on third base actually believe they've hit a triple.

I want to cast some simple stuff. I think Doug's Hyper-Pak
was impressive because of the length of the hollow runners.
If anyone can do a head, he knows how tricky it would be.
I need to learn to walk first. I've read lots of books, but no
experience at all. It would be really frustrating to do a
head, over and over again, without giving up on the project.

I'd start with simple brackets to adapt serpentine belts,
Sandem A/C brackets etc. Small castings. Maybe I can
attempt an alloy L-head for my old Mopars. These run
$750 or so new. Improved L-head combustion chambers
are being debated similar to those used on some Harley
Davidson racers, and B & S. I'd like a polished smoothie
head instead of the typical ribbed flat head. An EFI /6
manifold would be good too, with six castings that bolt
to a plenium rather than one big casting, probably five
as the two center runners can be paired.

The hobby castng gurus say a large head casting is
possible in a home shop but casting porosity would be
a concern to overcome. A pro foundry could deal with
that as its a text book problem for them. We have to
create good quality patterns that a foundry would not
laugh at !

I also want to do iron. Iron is probably better for A/C
brackets because alloy can crack when not heated
treated properly. But iron melts at almost 3 times the
heat as aluminum.

Dan, I really like my rose colored glasses. I had two Martini's after work! But I am a teacher- so each day, one has to gear up! Even though half of your kids are getting government assistance and most of your parents won't come in to talk with you about their child..... I knew the job was dangerous when I took it! (Super Chicken Quote)! All that aside I do enjoy your sense of humor! Today, I am an optimist !!! We will see about tomorrow!

_________________
66 Lil' Red Piggie Valiant (Mater Crusher) - Thanks Zilla!!!!! 72 Demon (Number 1 Son's)

hello,
have you thought about using this stuff for small quantities of molten iron?
this is a copy of a post on Inliners from a while ago.

Originally Posted By: Nexxussian
That's more than I knew when I asked. Thank You.

For me, I have a couple projects I would like to try in Aluminum, and a couple more in Iron. The last two are the ones I figure will be the most difficult (because it's Iron). I figure I could cast simple Aluminum parts like covers and what not here. I would be hard pressed to generate the heat (BTU's not just degrees) it would take to melt the Iron.



hello,
you might try this stuff to melt/supply iron for your casting job.
once lit,it is self sustaining and gets REAL hot.
a couple of links for your information.

http://www.youtube.com/watch?v=nR6K90cR8Lg

http://en.wikipedia.org/wiki/Thermite

if your job only needs small amounts of iron to cast,this may help.

cheers,CRM

Successful grey iron casting has some technical issues, such as carbon
and silicon content. Iron will melt very well with a waste
oil furnace, or propane. Traditionally coke or charcoal is burned
in a cupola but I have been unable to source any foundry coke
in South Texas. If you live in some cities in the northeast you
can sometimes find plenty of coke at rail road grade crossing
when the stuff bounces out of open cars. Shipping a couple
tons of coke is a killer these days. Waste oil is free, or very
cheap. Some use electricity to power the furnace, it has less
fumes so that you can melt alloy in a basement shop.

Nobody that I know can make steel at home, but grey iron is
commonly melted in backyards. At 2600F to melt iron
there is an extra safety concern contrasted with 900+F for
aluminum, which you can melt in a open camp fire. You
can suffer serious injuries as the hot metal will explode
with contact to moisture. Iron with incorrect silicon or
carbon can be very brittle and break easily, but aluminum
is basically what your scrap was.

You can build much of the foundry equipment yourself.
Or purchase from a company like this :
http://www.mifco.com/index.htm