Re: Insert vs babbit for hard use

Posted by Scott on November 30, 1997 at 18:45:42

In Reply to: Insert vs babbit for hard use
posted by Rick Botti on November 30, 1997 at 14:27:32

If you drive it a lot and drive it hard (ie keep up with traffic the best an A can), You would be better off with inserts. The "problem" with the babbit (other than finding someone who really knows what they are doing to pour it) is the thickness and softness of the bearing. Under heavy use you can "pound out" the babbit...it is so thick and soft that it can literally be beaten out of shape, causing the bearing to be loose and then fail completely. The center main is the most problematic spot, with a piston on either side of it. With inserts the bearing material is thin and on a much harder backing so it dosen't have that tendancy to "pound out" like the babbit, but is plenty thick for a normal "wear" life. It would also be much easier to put new inserts in later in life than to have the babbit poured again. If you are considering other mods check out the article at the Buckeye Pietenpol Association (Model A powered homebuilt aircraft) Page...in the air durability is a must! They used to have a photo or two of some bad babbit with some commentary, but I didn't see it this time.
Model A Ford Dyno Tests by Ron Kelley

E-Mail Comment to Webmaster