4/2/2009

 

NOS Model B Bearing Caps

 

Over the years my brother has accumulated some goodies. Here are two Model B caps that are both known to be NOS Ford. The one cap was pre-finished to standard and was in cosmoline. The other cap needed to be cut to fit and shows what the bearings would have looked like before the machining stage.

A quick note. When you pour babbitt in the block or the rear main cap you are pouring into a surface that is not tinned. The only thing holding the babbitt to the cap is some holes drilled into the rough surface. When the babbitt is poured and starts cooling the metal shrinks and will pull away from the surface some. While the babbitt is still warm they have to peen the babbitt to expand it out and correct the shrinkage.

In this photo the left cap is the un-finished cap. The brown tint on the finished right cap is from the cosmoline.

Notice here that the unfinished cap on the right has never had an oil tube. Notice the lack of a spot weld as
seen as on the left cap.

Here you can see the molded in oil groove in the thrust face.

Here you can see the start and finished babbitt thickness. The rear part would have had a semi-circle metal piece
inserted in to the oil slinger groove as an end seal for the rear thrust.

A close up of the un-finished cap. You can see the marks from the peening tool. We believe the peening tool was
some kind of an air hammer based on how tight and repetitive the marks are on the surface. The lines you see
are depressions in the surface. We would really like to see what the factory tool looked like. It is interesting to note
the raised portion of what appears to be a number 4. This was in the mold.

Notice the lowest or end peen is a thinner line, the other end is the same. You can see the oil relief cut into the
end to give the oil a full width swipe.

Here is a good view of the thrust surface oil groove that was molded in place.

On the left is the thickness of the unfinished babbitt and the right is the finished thickness. The markings are 1/64" wide.

This shows the fineness of the cut on the finished cap.

 

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