Quote:
Originally Posted by Helmsman
Deansbimmer, BEs page specifically says the VAC shells (they measure) has not increased clearance. Looking at VAC page they offer standard and .025 increased clearance. Curious on what shells you took out?
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Look at the measurements and reported nominal clearances. Numbers don't lie. VAC Clevite shells yielded .0021" clearance, which is obviously greater than factory clearance, although not as open as BE. The measurements throughout that page are similar to the numbers we get on our Mitutoyo equipment.
Quote:
Originally Posted by Helmsman
Ah, so the undersized are oversized really...  Anyways thanks for clarification. BE page still refer to the standard shell claiming not increased clearance but maybe way back when that was the case. All a bit confusing, but if I would guess its the same shell all along since they left the coated OEM. Anyway, some of them comes out in brilliant shape. |
Extra Clearance, Undersize, Oversize.... Again, one must look at the numbers, which don't lie. Admittedly, not all of us are engine builders who care to understand all of the details found in bearing spec paperwork. Nomenclature gets lost in translation as the person may be talking about the crankshaft journal or the bearing shell, which will instantly confuse if someone gets it backwards.
Extra clearance: Slight bearing-to-journal clearance is added to the standard (STD) bearing bore diameter, increasing oil clearance from factory spec.
Undersize: Refers to the bearing's reduced final inside bore diameter, used for damaged crankshafts that have been ground "Undersize" from factory dimension. Often erroneously called "oversized" because the bearing shell is thicker.
Oversize: Refers to the bearing's specified outside diameter, used for damaged rod bores or main bearing bores that have been honed larger than factory dimension to clean up damage. (This is not really used in S65 application as only King rod bearings are larger to run in honed rods. There are no oversized main bearings on the market)