[SEL] Engine bearings

[Rob Skinner]

On Aug 16, 2007, at 1:00 PM, Curt wrote:

> As a added point of discussion, aluminum case dengines (like Briggs  
> and
> Stratton) appear to have the crankshaft running in direct contact with
> the aluminum case. They are always flooded in oil, different than our
> hit and miss engines. But none the less, why do these bearing last so
> well? I wonder if it could be related to a large cast grain  
> structure as
> opposed to a fine grain structure the result of extruding or  
> rolling of
> aluminum shapes.


Hi Curt,
I couldn't contain my curiosity and just read through MH #12 for the  
characteristics of all the aluminum alloys listed.  Only two seemed  
remotely appropriate for Bill's application.  But if one is going  
through the trouble of fabricating new bearings, bronze would   
certainly be better.  But if machining the new part isn't practical,  
babbitt would seem like a good way to go.  After all, it's wonderful  
stuff.