I think this is a great idea George. Much much better than my original
concept. If you don't mind doing the pattern over. Better cosmetically
as well.

I added an idea.
Instead of using that great big 15 mm 180 mm diameter thick plate
in the center use a stiffening cylinder just a little larger than
Tracy's PSRU. The cylinder should be about 40 mm high.

Only a 15 mm thick  50 mm diameter slug of metal in the center
where the input shaft seal is located is all that is needed.

Also taper the ribs as suggested by somebody just a while ago.

And for good measure and the last little bit of weight saving
cast in the pie shaped holes between all the ribs. Not shown
in this illustration.

Good idea and good work George.

Paul Lamar

Paul,
I need a fairly flat and wide surface to bolt down the bellhousing for
machining purposes.
The ribs as they are now have been machined flat to give that surface.
The original s were deeper at the bottom of the housing originally.
Not having that flat surface to work from causes vibrations which play

havoc

on the machining process.

The center cylinder can and will serve that purpose. I use a similar
trick to machine the water pumps. use a 12 or 15 mm bolt through the
center hole to hold the whole works down. Also a few holes out in the
wings would not hurt.

Paul,
I made that suggestion, I have some nice 6 " steel tube that I gave them for
that purpose but they needed a bigger footprint - too much vibration.
With these CNC's the work has to be held down very solidly and the
bellhousing is a bit on the awkward side.

However the ribs were perfect for the application with minimal machining.
The towers are a good idea but add to the complexity of the finishing and
that extra cost.

Also you can cast in three or four towers out near the edges to be cut off
after the engine side of the bell housing is machined. I don't think
these are really necessary but would add support.

Paul Lamar

Be careful on that wall thickness.

Roger on that !
George (down under)

Well perhaps they can cut the ribs down when they flip it over.
They could surely cut off the towers.

I would hate to have to trim the ribs with hand tools to cut the weight.

Paul Lamar
 
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