Finally getting somewhere.
Part I: At this stage, the motor has been sitting with no
oil pan on for 2 days.
This is the driver side lower corner of the crankcase. Picture's not great because that's the crank counterweight in the way. You're seeing the
oil pressure relief spring. You can see a path of
oil from the 'window' of the spring boss which runs onto the pan rail. From there it travels slightly across the entire rear of the block pan rail. Like a dope, I cleaned that area before I took this snap.
There is no oil
above or around the spring boss on the block inner wall. Clearly the oil originates from the spring boss. There are no other internal drips including the rear main area. So I really feel this is the origin of the leak.
Part II:Careful cleaning of the windage tray and Canton pan has revealed that their mating surfaces had waves and warps and were not totally flat. The rear corners were actually bent
away from the block pan rail. After cleaning the gasket residue, I spent time with a persuader getting the surfaces flat. The flange on the pan was difficult but now lays perfectly flat on the work table.
My big conclusion is that oil from the relief spring seeped down the block wall and when it got to the pan rail, the uneven mating surface of the pan let it leak past. I know-gaskets are supposed to prevent that. I just don't know why they didn't.
THE BIG QUESTION: Guys, is it normal for oil to trickle from the relief spring when the motor hasn't run in 4 months? I want to stress-the engine runs perfectly and oil pressure is generous at all engine speeds.
Thanks to all those who got involved in this soap opera and would beg your patience for a few more thoughts from you all.