Rod and main bearings

School me on the rod and main bearing term "babbit". I think I understand "shell" bearings. Correct me of course if my understanding is skewed. The shell is made for a certain diameter of the crankshaft. Either the rod journals or the mains. The shell is made from copper brass steel??? but then covered with a "softer" material. Is'nt that material the babbit? the softer wearing surface of the shell or liner as they are referred to in my 522 SC, SO, S parts book. Dacaseguy is resleeving a DC-4. He states it has 3 point, so that would make it 1952 or newer. Would not that tractor have "liners" aka shells for rods and mains. Someone point me to s youtube video where I can grasp this concept of poured babbit bearings. I'm old, thick skulled and a show me learner thanks gobble

Tom - Dave Erb had an excellant article in Old Abe News years ago., send me your email and I'll copy and send it to you. Way to lengthy to post, but it's not a simple process and once understood can be worked with.

There were different mixes of Babbitt for different applications. I had to learn about pouring Babbitt when I had my sawmill. I was lucky to find Babbitt as it was. Higher speed shafts used a harder Babbitt than slow speed shafts. That's about all I remember on the subject.

So after watching a gentleman from Wisconsin pour mains and fit a crank for a Model T engine on youtube. I'm understanding this " poured babbit bearing thing a little better" Are all babbit poured bearing caps shimmed? I assume this is to allow removing shims to tighten the clearance after wear? I'm guessing that the babbit wears more than the crank shaft, is that wear somewhat symmetrical around the crank shaft. I guess we should learn something new everyday. I think I will have that covered today thanks you YT and youtube. gobble

Most of the wear will occur at the top and bottom due to the piston changing direction. That is why removing shims after years of use is very effective in extending the life of the babbitt.

D and LA Series was the last to use Babbitt poured rods if I am thinking right, VA and S series were amaong the first to use inserts in the rods
cnt

On shell bearings, there is a thin layer of babbitt. The rods on a DC Case are poured babbitt poured into the rod and cap and machined to fit the crank. Even new main insert (shell) bearings on a DC have to be line bored to fit the crank.
I have a setup jig to pour and line bore Model T engines in my shop.

Richard in NW SC