On Jan 8, 12:34*pm, " wrote:

What IS needed are aluminum head-castings having twice as much fin-
area as what's presently available. *This won't fit on a bug or bus so
there is no start-up money. *Coming up with the cores should have been
done by the EAA -- about fifty years ago. *The fact it wasn't *is good
evidence that it won't.

As I lay there taking my afternoon nap my mind wandered over this
subject and the thought came to me that we, at least I, have strayed
from the essence of this discussion and lost site of what we really
need to accomplish. Our goal. A real, hold in your hands, VW head
with adequate cooling capacity for aircraft power settings..

It has become quite clear that other than maybe 3 of us reading this
thread that the casting of things of this nature, "on the cheep" to
steal a phrase, is about as likely as being able to buy a Moller at
the local auto mart in the next decade. Even those that can grasp the
concepts needed to cast and machine some VW heads still need to build
or buy a whole set of new toy ..., er a ... tools. This doesn't get
any one closer to flying behind a VW conversion which is kind of the
point of this whole thought exercise isn't it?

The path being pursued might result in good cooling heads but only for
those of us that can make them as I doubt even once proven that
anybody would take on the production. There just wouldn't be enough
market. Could be wrong but I think we need to presume that these
things will never be kitted, only plans made items. Which means the
average home builder needs realistic ways to make them with out adding
another few hundred hours and dollars to the project just for heads.

'course there might be those that would enjoy learning casting as much
as building airplanes.................

My slumbering mind wandered to the solution of another of my flying
problems - the making of some props - and a comment my brother made
about using the same methods used to duplicate props to cut the fins
on our cast heads. Not a bad idea as I also remembered seeing a
tracing lathe operating at a science museum many years ago in Toronto
where I was attending an ultralight convention, way back in the late
70's. It was just finishing up duplicating a coke bottle and I
remember that it did a good enough job that the painted lettering was
duplicated in the steel replica as well.

So what would be so hard about adapting a propeller duplicating
pantograph to the task of finish machining a rough casting?

http://culverprops.com/culverintro.php Video here.
Substitute a Dremel/die grinder for the saw blade and add an
adjustable tracing wheel or point.

I'm thinking really basic casting here. Something with just the ports
and combustion chamber close to finished, with lumps else where as
needed. These castings would be simple enough that any back yard
caster that can make a core for the ports could ram them up using a
plaster cast pattern passed along from another builder. Those with
the desire could cast up several castings and sell for other
experimenters to finish at a very reasonable cost.

Since we are talking about using a pantograph the pattern need not be
1:1 scale. In fact something on the order of 3:1 lets the builder
work from full size drawings in plywood for fins and Bondo for glue
and filler when constructing the pattern.

Maybe with luck some homebuilders get together, use the divide and
conquer method, one making the castings and the second making the
milling machine?

But we now need a third homebuilder. One that can machine and install
the guides and valve seats and tap the various holes for studs. This
too is within the reach of a true home builder. The tools needed are
not that hard to make and the whole operation can be done by hand if
needed. I know some will scoff, but at one time just such tools were
sold by Assenmacher and others for the VW shops. The tough part was
getting the old seats out. They sold tools for that as well. A
simple drill press make things quicker. The required tools are quite
simple and anyone with access to a lathe and GOOD measuring tools can
make and use them. At this point any machine shop or VW mechanic can
hone/ream the guides, cut the seats with a Neway cutter (please use no
stones here), bore the head for the cylinder face and send you back to
bolt them on your short block.

Now with any luck I'll be over this crud in a few days and no longer
need my afternoon nap. Will be nice to get some real work done again
==========================
Leon McAtee