Pouring Babbit Bearing Inserts For An IHC Type M  Engine
By  TOM GREEN from MINNESOTA

This is how I made new crankshaft main babbit bearings for my
IHC / McCormick Deering Model M, 1 1/2 hp engine. I don't know if it was the best way,
but seeing how they turned out okay after a little trial and error, it must not have
been the worst way!
 

This is the mold I created to make the babbit insert main bearings for
my 1 1/2 hp McCormick Deering engine.
 


I started out with a piece of pipe, with a larger inside diameter
than the outside of the bearing shells would be, and a little longer.
I then used a hole saw to bore a hole in some 1/4" plate steel the same
size as the thrust lip on the original bearing insert.
I then welded the pipe to the plate's top surface.
You can see what I'm talking about by looking at photo 5.
Next I found a piece of 1 1/2" round stock (the size of the main crank journal,
drilled and tapped a 3/8" bolt hole to be able to bolt it down to a steel plate
Then I turned down to under-size and tapered the round stock in the lathe so I'd have
plenty of babbit in the casting to be able bore it close to size,
and have the taper to aid in removing the casting from the round stock.
Note the hose clamps. This is because I ended up sawing the mold in half
length-wise, after a failed attempt to remove a poured bearing from the one
piece mold. For the second try, I lightly siliconed the two mold pieces at
the sawed joint, and then clamped the two halves together tightly.
After, I C-clamped the mold down to the plate that had the round stock
bolted to it. You could drill and bolt the two plates together if you're
more talented than me. I tried, but never could get all the holes to work
out so the mold stayed centered around the round stock!
So..... I resorted to C-Clamps. This worked okay.
Also, I siliconed the mold down to the base plate, so molten babbit wouldn't
ooze out of the bottom of the mold.

 

I used an old gas hot plate hooked up to a 20lb. propane cylinder
to melt the babbit. It didn't take long to melt the babbitt down.
I'd add a chunk or two of babbit at a time, until I had the babbit
pot full of hot molten (DANGEROUS) babbit.
In this case, I was able to use my ladle for melting just enough
babbit for the pour, but I do have a larger pot if needed
 

This is right after the pour. I was anxious to see how
it turned out, so I started removing the mold within five
minutes after the pour. Had to wear gloves of course!
 

This is the bottom of the mold that was clamped down to the
base plate. You can see the thrust lip of the babbit bearing,
and the threaded bolt hole in the round stock.
 

Here's the babbit casting removed from the two piece mold.
I still have to tap out the center round stock.
Someone on the Internet suggested tapering the round stock on the lathe
to aid in removing it from the mold. That was a good idea!
Those guys on the SmokStak Message boards
are great!
 

The tapered round stock removed, with nothing broke!
 

I mounted a big adjustable reamer in the vice,
and removed the taper from the inside of the babbit
casting, a little at a time, to make the inside bore
of the babbit casting a uniform diameter.
I was able to turn the babbit casting by hand,
as the reamer cut the babbit with ease.
I wanted to end up with the babbit casting fitting snug
on the reamer, as it's going to become my arbor for
turning down the babbit in the lathe.
Note that the inside bore of the babbit casting is
still under size to the crankshaft main journal after
removing the taper, as I still plan on doing some boring
on the lathe, and final fitting by hand with a bearing scrapper.
 

To continue click page 2