VCCA Home Forums TECHNICAL - GENERAL Mechanical - Engine, Trans, etc Babbitt bearings-last year?

When did Chevrolet switch away from bearings that had to be poured or line bored?

In 1948 the main bearings were changed to the precision type. They did not require line boring and just one bearing could be replaced if necessary. Shims for adjustment were still used. The new precision bearing had thinner babbitt, reduced from about .014" to .003 to .007".
At that time Chevrolet stopped making the line bore type inserts for previous 6 Cyl. engine and made the precision bearing for those egines. That required all 3 or 4 inserts to be replaced initially. But there again that allowed just one could be replaced later if required.

As a note te 1932-1936 Ford V-8 engines had no inserts with the babbitt poured directly into the block/main bearing cap.

On modern engines the babbitt is onlty acout .002" thick and usually applied over copper or brass base.

Gene, Can a 207 34 model be converted to insert bearings. I've hunted thru the back notes and can'nt find any info. Do you know of anyone with this info. Jay Cross

Yes it can be converted. The original main bearings are inserts. The rods can be inserted by a machine shop that knows what they are doing. Even with insert main bearings they should be line bored to make sure they are sized and aligned.

Thanks, Chipper for the reply on the con rod inserts. Thanks again J.

I haven't looked lately but remember a machine shop in the NW that advertised in the G&D to convert rods to inserts. '32 and newer are supposed to be easier because the thrust surface on the rods is steel instead of babbitt. I don't think it is a problem with the earlier rods as the crank end sides should not touch the crank if pistons and piston end of the rod are in good shape.

It depends on the individual rod. If there's enough material that can safely be removed for the insert then yes, they can be converted.
There's a man near me, popular within the AACA, who I've dealt with that can do either poured or insert. For over 50 years he has only worked on old engines and people from all over the country ship their projects to him. Especially fire houses with those gigantic six cylinders and multitudes of model T and stovebolt engines. Brand or age doesn't matter, Mopar, Studebaker, Nash, etc. and any foreign engine. If interested - Fred Seydel
six,one,zero,three,eight,three,seven,six,seven,four