In the days before Plastigauge came into being, bearings got adjusted by sandwiching a thin piece of shim stock between the crankshaft and a bearing cap, and shimming until the crank could be turned with a slight amount of resistance. The same procedure was done for every bearing in the engine, rods and mains. The really skilled Babbit bearing fitters "scraped" the bearings first, before shimming for clearance, trimming away any high spots on the bearing with a razor-sharp cutter made from a 3-corner file with the teeth ground away. That procedure still works well, if you're patient enough to do it. It's very labor-intensive. Findintg an oldtimer like me who still scrape-fits bearings is the tough part, but it's a skill you can learn if you're willing to spend some time. It involves coating the bearing with an indicator dye called Prussian Blue, turning the crank, and looking for bright spots, then gently scraping the soft metal away until you get a smooth blue smear with no streaks. Then shim for clearance. It will keep you out of the beer joinnts at night for weeks at a time! Have fun!
Jerry
