Well, ive got about 3.5 - 4 inches between my BIX and my 172mm Rotron.
When I cut the shroud, it just worked (cut) out best when I made that much of a standoff. Ill post some pics when I find my digital camera...
It looks cool, ive got the rotron mounted in the top of my pc71 with the shroud/rad (painted black) connected to the bottom of the fan. I have all the air in the case being sucked through the radiator, I know I could probably get a fee more degrees cooler if I directly vented in cool air through the rad, but Ive got all my case fans (4) bringing air in from both sides. The BIX + 172mm Fan + eheim 1250 + 1/2ID tubing is very effecient for me, my temps going in to my rad and going out of my rad on differ by 1degree, maybe 2 degrees at full load. Im cooling an AMD xp1500 and a NB, I cant see needing anything larger than the BIX with any *home* setup for me... of course if you talking about cooling multiple systems through one BIX, I think I would try it, my system doesnt even seem to sweat with it... I would worry more about the flow rate with mulitiple systems and having to pump more water... But then again, im just some 'hot stank' I could be wrong!
