01-05-2018, 08:12 AM
Stephen,
As an external observer it's a little difficult to assess your position on account of the slender amount of information you have shared. If you are newly building up an engine there's more than a little chance that the C/M is out of line with the front and rear mains. Shimming can correct this but a far better solution is to fabricate a new C/M housing and have it line bored. As observed above, this should be done with the major bits properly assembled so it doesn't pull out of line when built up. My own engine was built in this manner by Stuart Rolt in the 80's and has been completely reliable. He used to bore out the new housings with a bloody great reamer mounted in a lathe.
Even thus corrected though, a new set of shells will often bind if not administered the aforementioned tap or two on assembly, I've had the same issue myself. Built up two or three times and went tight on torque application; once everything seated into place properly it runs freely. (I had this tip myself from Stuart when I made the same enquiry to him years ago).
A parting thought, do make sure the housing is assembled the right way around, front should be marked.
If the car has been running reliably prior to whatever you are doing now I would think very hard before shimming out the C/M.
As an external observer it's a little difficult to assess your position on account of the slender amount of information you have shared. If you are newly building up an engine there's more than a little chance that the C/M is out of line with the front and rear mains. Shimming can correct this but a far better solution is to fabricate a new C/M housing and have it line bored. As observed above, this should be done with the major bits properly assembled so it doesn't pull out of line when built up. My own engine was built in this manner by Stuart Rolt in the 80's and has been completely reliable. He used to bore out the new housings with a bloody great reamer mounted in a lathe.
Even thus corrected though, a new set of shells will often bind if not administered the aforementioned tap or two on assembly, I've had the same issue myself. Built up two or three times and went tight on torque application; once everything seated into place properly it runs freely. (I had this tip myself from Stuart when I made the same enquiry to him years ago).
A parting thought, do make sure the housing is assembled the right way around, front should be marked.
If the car has been running reliably prior to whatever you are doing now I would think very hard before shimming out the C/M.