rebabbiting

I have heard that rod and main bearings can be rebabbited. Does anyone know what this process involves? Is it worth it to have expensive bearings, such as md bearings, rebabbited?
Thanks and Merry Christmas.

they can be, but it is hit or miss on the quality. NOS standard, 0.010, and 0.030 main bearing sets are still available........

Rebabbiting is usually done only to those engines that have poured babbit bearings instead of precision bearings. The layer of babbit is usually only about .001" to .003" thick on a precision bearing.

An md does not have babbit bearings.Its got inserts. Hoss

Babbitt bearings are a class of plain bearings that have a composition material that is lining the inner surface of the outer part of the assembly.
Babbitt bearings are composed of lead, tin, antimony, copper and other ingredients including arsenic. These are available in several classes of service and load/speed ratings.
They are generally poured in place. This means the material is heated to melting temp and poured into a form conforming to the shape of the journal. (journal being the smooth shaft or surface running inside the bearing) The form used is made to allow the cast shape to be smaller than needed, allowing the scraping or machining of the surface to adjust the final clearance. Usually in the area of .0015 to .0025". on engine bearings.
The composition is adjusted in hardness to allow particles of grit and contamination to embed into the bearing material rather than stay stuck to the surface making an abrasive machine tool out of the particle. No plain bearing is ever designed to be without lubricant that through viscous film strength and flow characteristics, floats the bearing above the journal.

Babbitt (as cast in place) is not the same as an insert. Inserts are also composition, but usually much more complex.
Consisting of an outer steel shell with a Copper coating, then additional layers of material and mesh structural components (as many as five layers) with the inner layer being softest. Silver and silver alloys are often found in the inner layer of specialty bearing inserts. Again it is embedment capability driving the choice of alloy.

An insert could be re-manufactured, but it would be a circumstance driven by the lack of any other new insert. The support of the multiple layers in an insert makes it much more structurally sound than Babbitt.

I hope this makes sense to the question. Jim