Main bearing question

[The Oil Soup]

I am in the process of rebuilding a '55 230, when installing the forward (#1) main bearing halves noticed that the oil groove in the two halves does not match up, in other words they are off set from one another. It seems that the lower half should be a mirror image of the upper half but I have two upper halves. The main cap only fits correctly one way. Any help? Thanks

[kencombs]

I Just looked at a new set of Clevite mains for a 230.  Only the thrust bearing is grooved top and bottom.  The other three are only grooved on the top half.

 

The old set, still in the block are the same.  Methinks you have your top and bottom halves mismatched.

[Dodgeb4ya]

Just saw this..

The OE MoPar and all NOSR main bearings have matching grooves top and bottom.

The modern offshore replacements only have one shell with a groove...

Check out 415M Federal Mogul on Ebay to see pics of how original bearings were manufactured.

[Plymouthy Adams]

I believe you would have two uppers on the #1 brg if both halves have an oil feed hole.  The upper only has the oil feed hole

[Dodgeb4ya]

Yep the mains need only one shell with the oil hole..The upper shell oil hole matches the block oil hole.

Both upper and lower bearings should have a groove top and bottom for good lubrication.

Rear main is a one way assembly installation.

 

Edited January 2, 2020 by Dodgeb4ya

[The Oil Soup]

My concern was more about the fact that the oil groove in the #1 main bearing lower half doesn't line up with the upper half, but if replacement bearings don't even have an oil groove at all then it must not be that critical. There is only one way to correctly install the #1 bearing halves. Bearings 1 through 3 have holes in both halves. I spoke with someone at Bernbaums (Gary?) and he said that was normal.

[Dodgeb4ya]

I think that's typical modern day after market save some  manufacturing costs...one shell fits upper and lower even though off set.....

The OE MoPar #1 bearing shells....oiling groove matches top to bottom.

The way it should be. This  for proper upper and lower bearing oiling.

 Gary is just a parts seller man. He should know the lower shell is getting 30-50% less oil than the upper shell.

 The most load is on the lower main bearings. They need plenty of oil too.

Edited May 10, 2020 by Dodgeb4ya

[The Oil Soup]

I suppose a solution to this would be to machine a relief in the lower bearing housing to flip the bearing 180* and line up the oil groove.