How to / DIY > Engines

Makeshift repairs and babbit

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scott p:
Out of curiosity I did a search. Looks like babbit comes in a lot of different flavors,and is readily available.

MachineNLectricMan:

--- Quote from: 38ac on June 18, 2021, 02:38:06 AM ---Actually some if not all modern engine earing shells still use a layer of babbit over the backing metal it serves to cushion shock loads and provide crankshaft protection. How thick depends on the application. Ford may have had something to do with thin shell development but Henry's Model Ts and As had poured babbitt bearings.
As for pouring an emergency repair bearing it is indeed a satisfactory repair when there is no other option. As an example there are no big end shells available for the Z4 Banfords engines. When I rebuild one the rod goes to a specialist who pours babbitt directly in the rod and adds a shim pack so it can be adjusted down the road if needed. Same would work for a CS type but when replacement shells in every conceivable undersize are easy obained and cheap there is really no reason go another route outside of an emergency repair and try to find Babbitt in your home town, might as well order a bearing as order babbitt.

--- End quote ---

Actually it is a thin layer of a special aluminum alloy applied over a layer of copper on the soft steel backing shell for most modern shell bearings. Some manufacturers cut corners and do not use the copper under-layer.  The copper under-layer also was once used when babbit was used for the bearing material as it helps the bonding of the babbit to the steel.

You have to appreciate the simplicity and effectiveness of some of the old technologies. With so much of the world going down the toilet now days, we may find ourselves reverting back to some of these older methods in the near future.

38ac:

--- Quote from: scott p on June 18, 2021, 09:53:24 PM ---Out of curiosity I did a search. Looks like babbit comes in a lot of different flavors,and is readily available.

--- End quote ---

Yes , Babbitt  is a blend of metals and there is no stabdard mixture. Hardness varies with the application. If the babbitt is too soft it actually flows over time and if too hard it cracks and chips,

scott p:
Interesting observation 38ac. I hadn't considered that sort of thing. I think I will try brass rather than the babbit I have here.

I believe I read a post where you might have a lathe. Have you ever made bearings or bushings? 

I am including a couple pictures showing what I will try first in my attempt to make a proper bushing. One shows a shaft slightly smaller that the wrist pin. The second pict is the outer container to hold the brass. If I can get the brass out or off of the these two items I will consider myself lucky.

38ac:
Yes I do have a fairly complete machine shop. I have turned 1000s of press fit bushings and made a few sets of bearing shells from Silicon Bronze.

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