> Now I think I have a reasonable explanation:  He had air trapped somewhere
> in the top of his rad/cores or hoses in that vicinity, which impaired his
> cooling; then by reversing "in and out", he started moving the air or air
> bubbles out with the flow.  Makes sense to me and solidifies my position
> that my hot coolant from the engine will enter the BOTTOM of  both of my
> cores via a Y or splitter in between them, and exit at the TOP of each, into
> another Y.

I have my inlets and outlets for both cores on the bottom, so the top would seem to have great potential for trapped air.  I was thinking of addind a bleed port on the top of the cores, but Ed talked me out of it (and will be in trouble if this doesn't work <g>).  His is set up the same way, and he has no problems with air being permanently trapped.  Since I'll have a coolant pressure gauge with the new setup (thanks to the EM-2), I should be able to tell if there is air in the system by how fast the pressure comes up with temp.  

I have to admit that I'm still mighty tempted to add a couple small bleed ports while it's still easy to do.  

Cheers,
Rusty (any excuse to weld something)