Hi Tom,
It must be the season for pouring babbitt. I really like the look of your fixture, that’s first class. I poured both halves together assembled in the rod which worked OK after a few false starts. This is for a 1929 Wallis 20-30 I am working on. See photos below.
I found that I had to have the bronze shells nicely tinned and then after the fixture was heated up and just before pouring the babbitt I melted some flux onto the tinned surface to make sure the babbitt stuck to the bronze. Even then I had a few small bubbles in the babbitt which left a hole or two after machining to size. I don’t think that will matter , just another small oil reservoir in the bearing surface.
For the mains I tried using wooden plugs to close the oil holes in the shells but they just popped out and spilled the babbitt all over. I put a hose clamp and some “babbittrite” ( grey putty) around the wood plugs to hold them in place.
I used No. 2 babbitt, so called “hard” babbitt with no lead in it that I purchased from www.rotometals.com
My machining setup is shown below. The knurled knob below the wrist pin is threaded so that the pin can be raised up or down to make the axis of the pin parallel to the milling spindle before boring the babbitt. I checked the alignment of the wrist pin in both directions using a dial indicator in the mill. The machining went easier than I expected.
I still have the front main to pour. It has the thrust surface on each side and I am still pondering how best to fixture that. I haven’t machined the main bearing halves, I think I will do that in a fixture fastened to a lathe faceplate rather than on the mill.
Last picture, new shims, brass stock is laminated, five laminations of .002 inch.
Best wishes, Alan Painter, Brownsville, Oregon