Pouring Babbitt in Flange Bearings

[Jim Gorter]

I am working on a garden tractor which has four babbitted flange bearings, two at 1.25 inch diam for mains and two at 1.00 inch for cam. They are flange type bearings.Any one with babbitting experience, how should I set up the dummy shaft for pouring and how do i work the clearance so I can remove the shaft when cool. I want to pour first then havethe bores turned out to the shaft size. Any help or tips/advice is appreciated, Thanks, Jim.

[John Hammink]

Jim take a look at my site about pouring flanged bearings for the "M" engines, maybe it gives you an idea for yours.
It can be seen at:
http://www.oldengine.org/members/ham...uringMpage.htm

[George Andreasen]

I've poured a few bearings, so here's how I'd do it....use a piece of plate steel (3/8" or so), drill and tap it to receive a polished, undersized dummy shaft long enough to do the bearing. Screw the dummy into the plate, coat it with carbon from an acetyene torch, place the CLEANED bearing shell over the dummy, place babbiting putty, warm it up and pour your preheated metal. After it cools use a gentle twisting upward motion to free the bearing. Chuck the whole assembly into a lathe and bore to size, allowing about .002" clearance for oil. Now that's MY thinking...I'm sure there will be a lot of folks that have more experience than me and might come up with an easier method. In any case YOU CAN DO IT. Good luck. George

[Jim Gorter]

Thanks John and George, Do you think the dummy shaft should be tapered to allow for easy removal. I would keep it undersized to allow for boring afterwards. what about centering the dummy shaft prior to pour? Or not worry about it and have the lathe recenter the bore? Also what steps on cleaning the housing and do you recommend using the tinning material to stick the babbitt to the housing. BTW, very nice article on the M insert pour John, very informative and great pictures. Thanks Jim.

[George Andreasen]

Jim,
Clean the bearing housing by melting out any old babbit with a torch, then use a wire wheel after it cools. There should be pockets inside and these are anchor holes for the babbit, although just a rough surface is fine. No, the dummy does not have to be tapered, just clean and polished. No burrs etc. This makes it easy to remove the poured bearing. It may feel stuck at first, but it's just a tight fit. Twist it for removal and it will come off. Remember the carbon before pouring! I just center mine by eye. Make it considerably undersized and let the lathe bore it and center it for you. All of this sounds very complicated but you'll find it's actually dirt simple and very rewarding when you do your own! George

[Lyle Stomp]

One of the best ways to get the clearance when pouring bearings is to wrap paper around the shaft. I usually glue the seam or sometimes i will tape it on the inside. Make sure the paper is wrapped as tight as possible otherwise you will have a bubble in the paper which will cause a low spot in your bearing. If it is a high speed bearing I suggest pouring undersize and boring it out. I wish you luck, Babbiting can be tricky. Lyle

[ben frazer]

In my experience, I would definately taper the dummy shaft slightly, say half a degree or so because even with carbon or any other non-stick application, I have never had one come out without a hammer or press. Even with a taper you will probably have to give it a good tap!

[Craig A]

Hey Jim!
I know you tackled the babbitting thing and, apparently, with success....
What's the lastest in your BABBITTING 101 learning experience.....or by now maybe you've graduated to BABBITTING 401.........
Craig

[ramsay]

Originally Posted by Lyle Stomp

One of the best ways to get the clearance when pouring bearings is to wrap paper around the shaft. I usually glue the seam or sometimes i will tape it on the inside. Make sure the paper is wrapped as tight as possible otherwise you will have a bubble in the paper which will cause a low spot in your bearing. If it is a high speed bearing I suggest pouring undersize and boring it out. I wish you luck, Babbiting can be tricky. Lyle

Hello: Anyone ever hear of "smoking the mandrel"? Put some smut on the mandrel from an oil lamp flame or acetelyne torch to aid in removal.. Mike