The firewall here at school filters out virtually all pictures, so I can't comment on the ones you mention. My personal rule of thumb is this: If I can hang a fingernail in a rust pit, it's probably too deep to run a piston ring over it without getting blowby and/or oil consumption. Slightly rough or discolored spots, while not ideal, are usually acceptable as long as there's not a large area that's affected. Crankshafts- - - -minor pits or low spots, no real problem, as long as the journal is round and not over .001" under the specified diameter. For instance, I'll reassemble a .011" undersize (round) rod or main bearing, using new bearing shells. More than .001" out of round on a rod or main journal needs a regrind, regardless of diameter. Ditto for taper- - - -slightly undersized but straight from side to side is OK, bigger on one side than the other, regrind it. Deep scoring or roughness on any crankshaft journal- - - -regrind or replace!
Taper wear in cylinders- - - - -.005" MAXIMUM! A piston ring that has to expand and contract constantly can't keep a good seal with the cylinder wall, and it loses its spring tension in a hurry. If a couple of thousandths of taper can be honed out to straighten the cylinder walls, and the piston skirts knurled to reestablish the proper skirt clearance, OK, but do a very good cleanup with hot soapy water and a scrub brush after honing.
Reassemble or machine- - - -that's a judgement call that comes with years of experience and hundreds or thousands of engines inspected- - - -no substitute for experience!
Jerry
