If the mains and rods bearing/crankshaft clearance is .001-.0015, wouldn't .002 be maybe a bit better for the little extra oil film?
Rods will start to talk to you at .003
Tyrone, generally speaking, you want .001" clearance for every 1" of journal diameter for most engines ever made.
So .001-.0015" is basically spot on. I myself would shoot for .0015-.00175", but most don't have accurate ways to measure. I certainly would not want over .002" for sure.
After I set the clearance, I use Timesaver.
Larry, Timesaver? Lapping compound? Or is it ink to find highs and lows?
Tyrone, time saver is lapping compound but organic and will not imbed in the Babbitt, cannot over cut as it will wear out rather quickly and leave you about .0015 clearance. If you are persistent you can achieve 100% contact on a worn crank and bearings. Probably not needed on a newly turned crank or new crank and new bearings but cannot hurt anything. You don't even have to worry about cleaning the residue out after lapping(I usually do) as it will flush out when you change oil.