Simon... Before having a crank ground, I always Dremel Grind a shallow cup across the journal to enlarge the oilway width slightly and restore the wider oil film where oil enters the bearing surface. New cranks had a teardrop or similar cutaway machined in production, but successive regrinds narrow the width of the teardrop cup, until it almost disappears, leaving a very sharp edge to cut a nice central groove in your new shells. Grind the shallow cup first, before grinding the crank, have it ground if necessary, then finally polish the edge again to ensure a smooth transition from oilway to journal surface.
I have already posted my thoughts on this in the thread about the drive side conrod oil bleed hole. It is to do with the reduction of surface area with depth of a shallow cone, like why your vintage Martini Glass seems to empty rather quickly.
Top Quality Sludge, you make it look easy.
Swarfy.
