Don't wrap it up up and speed shift, you may end up with a rod through the engine side. It is probably the rod bearings and mains letting too much oil flow past instead of making a film on the bearings. The previous abuse before you had it is the clue. That "dirt" in old oil is the worn part of the bearings, rings, carbon from blowby, and it is abrasive, so wears things a little quicker.
