thank you guys,
well i'm feeling guilty but i remember to have cleaned the crank pretty good, brush, solvent and compressed air several times but after all as you says it can be dirty anyway.
Block has been bored and honed, here in Italy is hard to find a decent machine shop and as "decent" i mean just to do their work and make sure all the tolerances are ok.
They probably haven't the tool to bore the maincaps and mine sure wasn't, block was in very good conditions, that's for sure but probably maincaps bores now are not perfectly round and this cause this kind of wear.
As i've said before, there's a complete bearing kit on the shelf i've brought for another engine so i can change them but my concern is to get them quicky at the same point as before.
Engine is already on so work on it is not so suitable and even the basic measurements could be difficult now.
How long bearings will last in this conditions in your opinion?