Babbitt conversion to insert bearings

[David Rainville]

Thanks for your responses, it's much appreciated and enlightening.

[Wm Steed]

The question about babbitt bearings vs inserts comes up quite often,.... see the topic about main bearing groves in babbitt bearing, my response of 12/19 and the other responses, especially the one by Carla .

I think the issue boils down to.... is it alright to modify and engine so it will preform better, or do you stick to strictly stock... as Walter P. or Henry F. made it.
On the problem side... can you find a machine shop that will do the babbitt work and do it right? ... Can you find a machine shop that has the skill and equipment to convert from babbitts to inserts?  It is getting more and more difficult to get quality work of any kind done, leave lone something out of the ordinary.

On the oil question......... It has been my understanding that detergent oils should not be used in engines with babbitt bearings... The detergents can attack the babbitt causing an early failure of same....Bill

[David Rainville]

I admittedly don't know just how babbitt bearings are done but am of the understanding that they don't have the wear durability of insert bearings and in all the "oil type" discussions on this web site, no one seems to know just which oil should be used if you have babbitt bearings. I realize that babbitts are poured bearings of various metal mixtures, depending on which manufacture is setting the spec's. This just doesn't seem to be the best solution for a bearing material. I guess my question is, what physical constraint prevents the conversion to insert bearings for a 31 Plymouth engine.

[johnRFain29U]

My 29 has original insert brass bearings on the mains - lined in babbitt.  The rods are babbitt poured directly into the rod.  What is the problem you are trying to address?

[David Rainville]

Can someone explain to me why a 31 Plymouth engine with babbitt bearings can't be converted to insert type bearings.