Main Bearing Caps interchangeable??

[BaySHO Performance]

As we know, the con rods and caps are line bored and a stamp placed over the two halves so that they can't get mixed up.

What about the main bearings? Are the main bearing caps and block also line bored, or are the caps interchangeable between engines?

 

[AREA 91]

They are matched to the block. You would have to measure to make sure the clearance is correct.

 

[sperold]

In the old days they were numbered and had an arrow indication the front of the engine. So in effect they are "line bored" and matched.
If you had all the caps from a block and did not know the order, you may be able to measure and determine where they best fit, but it wouldn't be easy without some sophisticated equipment. It would be helpful to have the original crank also.

 

[rubydist]

iirc the SHO main caps are indeed numbered and have an arrow indicating orientation.

I would not be swapping a cap from one engine to another.

 

[sperold]

Main bearings are difficult to buy and it has been reported that the regular Taurus 3 liter engine bearing have been considered as a replacement. Problem is they are .030 larger on the OD (I think) and 2 sets are needed as the thrust bearing is different in the SHO.

In a case like this, you could use mismatched caps as they are getting a line bore anyways, but then there is the "tang" issue that has to be solved.

 

[jimtash]

Main bearings are difficult to buy and it has been reported that the regular Taurus 3 liter engine bearing have been considered as a replacement. Problem is they are .030 larger on the OD (I think) and 2 sets are needed as the thrust bearing is different in the SHO.

In a case like this, you could use mismatched caps as they are getting a line bore anyways, but then there is the "tang" issue that has to be solved.

I think the trust bearing is built into one of the regular 3.0's main bearings is it not? I recall the have an "overhang" on one pair that is the thrust bearing.