Well, that part of it is DangerDen's handiwork
I only modified it and made a top for nb use. Anyway, I'm just cooling a rather large chip here so water simply flowing in one side, cover a great deal of area, and flowing out the other works really well. The nb doesn't put out near as much heat as the small die of a cpu does.
Good luck with the spiral, I'm interested how you go about making it fit and mount. I personally am just waiting to have a spare $1500 or so to throw down on a little mill and accessories so I can truely make my own blocks and other stuff. Yay
Oh and I'm assuming it's amd we're talking about here.. what board in particular are you trying this on?