17-11-2021, 11:33 AM
If the existing crank has been ground and the new one is standard size, that is likely to be an awful lot of scraping; typically crank grinds are done in 0.010" (10 thou') increments, your crank could easily be '30 under' or more. Whereas each scraper stroke gives a 'peeling' of about 0.0001" ( one ten thousanth). The big ends can be bored in a milling machine or (by using a simple jig) on a lathe to size, leaving no, or minimal scraping to get a good final fit. An 'old school' machine shop or any decent jobbing engineer should be able to do that boring for you.