R.White Posted March 26, 2017 Share Posted March 26, 2017 I am presently rebuilding the engine on my '26 touring and I have noticed something that I don't quite understand. The crankshaft bearings have thick shims under the caps which can be machined down to take up clearances. Each shim has a hole through which a stud or bolt passes but all the shims have a slight chamfer machined on one side of the hole. Can anyone explain why? Also, which way up should they go please? Ray. Link to comment Share on other sites More sharing options...
robert b Posted March 26, 2017 Share Posted March 26, 2017 Ray I have all ways put the chamfer to the block side , I would think this to allow for any slight pulling of the stud in the block to allow flat seating of the shim. The studs go deep into block and are pinned, so one would not expect them to move , but if some in the past over tightened them it is possible for them to pull.Have not seen any that have pulled in the block to date, but it is always possible. Hope this helps. Bob Link to comment Share on other sites More sharing options...
R.White Posted March 26, 2017 Author Share Posted March 26, 2017 Thanks Bob. I have learned something today, Fortunately, there is no sign of abuse to the studs and that area of the block is perfectly flat. The theory is sound for the mains but it doesn't explain the big end shims unless it was easier to treat all the shims the same from the start. Anyway, I now how best to fit the shims. Thanks. Ray. Link to comment Share on other sites More sharing options...
robert b Posted March 26, 2017 Share Posted March 26, 2017 (edited) Never thought about big end shims, good question ,may be hole clean up after broaching ? bob Edited March 26, 2017 by robert b (see edit history) Link to comment Share on other sites More sharing options...
R.White Posted March 26, 2017 Author Share Posted March 26, 2017 Maybe. I have had to get a set of big end bolts machined as some of mine had been overtightened. I am still waiting for them! Today I made a start on the engine and put the crank in. It was interesting to see where the reverse of the shells had been stamped DB and US the markings had been imprinted on the underside (in the block) - so easy to see which way round they originally went if they ever got muddled up. Fortunately, as I took the trouble to carefully set the shells out in the correct order, mine are OK... that is except one of the con rod caps which had been previously fitted the wrong way round so the dipper would have been partly starved of oil! As you know, in the absence of a pressurised system, the caps are designed to collect oil from troughs suspended in the pan. You wouldn't believe the things I have found with this car... Some mothers do have 'em. Cheers Ray. 1 Link to comment Share on other sites More sharing options...
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