Building Full Circle Crankshafts
I have never seen a full circle crank come apart.
To make a full circle crank, one must machine a couple of rings that will form the OD of the crank.
These are typically made from aluminum, and only about .020" to .040" thick.
The OD must match the original crankshaft OD (if it were round), or in the case of the Macs & Westbends, no larger than the hole in the block that you must slide the crank in through..
The width needs to be as wide as the original crank throws.
Then the crank needs to be machined down so that these rings will just slip over it.
I normally leave a lip towards the rod, so that the rings will locate properly.
Then it is onto the stuffing........
Mix 4 cups of bread crumbs, salt, pepper.........
oops, wrong recipe !
Do one side at a time.
Cut out a flat piece of plastic to form the rod side of the stuffing.
Clamp the crank on end (vertical) in soft jaws.
Wedge the plastic inner mold piece up against the counterweight.
Mix up a little epoxy, of what ever brand or flavor you can find.
Smear a coat around the ID of the ring, and on the OD portions of the crank.
Slide the ring into place, and fill all the voids with more epoxy.
I pre-cut balsa wood cores to fill the larger voids, just to cut down the added weight around the rod side of the crank. They have to be at least .060" away from any edge so that the epoxy fully encapsulates the porous wood.
If you end up with any voids, bubbles, etc., they can be filled later.
When one side is done, flip the crank over, and do the other side.