VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1912-1928 More on babbitt

Greetings,
I have been talking with several different babbitt shops around the country and there is more to this subject than I ever imagined. On the 28 engine, the center main shell appears to be composed of bronze. The front and rear bearing shells appear to be composed of nickel. Is that correct? Also, there are at least two different types of babbitt. One is lead-based and one is tin-based. Which is best suited for these old engines?

Thanks,
Ron

All shells should be brass, and DO NOT use lead babbitt

Interesting. The front and rear mains are original and have bowtie emblems but are not brass. The center may well be brass. I am finding that each so-called babbitt expert I talk with gives me conflicting information and I have spoken with six shops so far. For example, one vendor listed here on vccachat as "positive" told me they can't re-babbit the front and rear shells because they are pot metal. They pour lead-based babbitt directly on the block and get this - they don't recommend using shims (red flags going off all over). Also there are several vendors where I have spoken with two different people at the same shop and they give me different price quotes. Also different shops' prices vary wildly. This is quite frustrating to me because this is an expensive service and I want it done right the first time. I am tempted to pick up a book on the subject and do the work myself. It shouldn't be such a black art. Here are the shells:



Thanks,
Ron

Hi, aren't bearing shells tinned before applying the babbit, this
gives adhesion of the babbit metal to the shell. Ever seen the tinning on the big end of a conrod ??
Use a magnet to see if the shells are magnetic?? (IE Steel) .
Jack

Rusty
If the front and rear shells have a bowtie stamp,they must be pieces that Chevy sold, however out of ten + or - engines that I've been into, all have had brass shells. I seriously doubt that yours are "pot metal" as I dont think it's possible to get the babbitt to stick to it. I would be inclined to think that yours are solid babbitt, if scraping the front or back edge doesn't show brass, and a magnet wont stick. Have a go at doing them yourself, like you say, its not impossible- I did a set for a four cylinder Nash not too long ago, and others in the past. Use the best tin base babbitt that you can get- it's expensive, but there isn't any sense in going to all the work and taking a cheap pill on the material. One word of warning- if you make, or have made, new brass shells, rough them to within about 1/8" of size, then heat them to a dull red, just visible in a dark place (about 900º F) and let them air cool slowly. This will relieve the machining stresses. Then finish to size. The thinner the layer of babbitt the better, but the more accurate your machining must be also! If you don't stress relieve before finish machining, the heat of the babbitt will do it when you pour, but then the outside diameter of the shells wont be correct. Ask me how I know.

If you decide to go ahead, and need more info email me at ebtm3@juno.com

Herb Kephart

CORRECTION!
After digging out a few used main shells, and checking them carefully, I have found that the front and rear ones that I have saved are solid babbitt, apparently die-cast. There is a brass discoloration on the outside diameter, which must have been caused by heat or oil, but the od can be easily scratched with a knife. The FB mains that I have are the same way (solid babbitt front and rear, brass backed center). This makes me wonder if the brass backed fronts and rears that I ran into in the past were aftermarket items perhaps?

Herb Kephart