#127693, "RE: Machine shop question" In response to In response to 1 Sep-11-09 11:04 AM by Corbin
If they are doing the machining and assembly, then they should determine the appropriate bearing sizes. They might have to machine down one of the crank journals to get smooth metal and the appropriate clearances. If you had already bought bearings, you would then have to buy new ones. However, you might want to request specific clearances for each set of bearings (based on a shop manual or advice). If you do that, you would want them to record the actual measured clearances, so you could compare that to your request. I do suggest that you request them to list the bearing sizes they use and every machining process they do. That lets you do a basic error check on their work and might help you with future decisions. Unless you have lots of experience with this shop, you should expect them to cut corners, not measure things carefully, and generally bolt everything together as quickly as possible. Be specific about your needs and do your best to double-check their work.