[SEL] white metal for bearings (Babbitt)

[Rob Skinner]

On Jul 8, 2008, at 7:27 PM, Peter Lowe wrote:
> 1. What is the tolerance between the crankshaft and the bearing ID.  
> The crankshaft is 1 1/2" dia. and the bearing is about 4 1/2" long.  
> How many thou. do I allow.?

Hey bro,
While I'm sure there are numbers that will directly answer your  
question, I would attack it from another angle.  Using bluing and a  
scraper, keep taking off material until the shaft turns without  
appreciable drag.

> 2.  The oil groove in the bearing, should it be on top of the  
> bearing where the oil comes through and is there a need for one on  
> the bottom.

Don't put the groove on the area that gets the most force on the power  
stroke.  In your case, the groove should be at the top.  In this  
situation, I've seen some that are X shaped, and some that are a  
straight line perpendicular to the rotation.  Regardless, the groove  
should not go to the ends of the bearing.  That would allow the oil to  
flow right out, rather than forming a cushion within the bearing.  I  
wouldn't bother to direct the oil back into the middle, it will get  
oil drips no matter what you do.  Use your judgement here and you'll  
be fine.

> You might say, who cares it will not be run that often, but it is an  
> exercise for me in machining also.

???What??? You mean you're going to rebuild it with the intention of  
not running it???  The Brothers Koori can fix things that don't work  
afterwards.  If we don't get to see a youtube of that engine running  
in the near future, we Americans are going to want our National  
Heritage returned to our shores.

Adios!