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Radiator, block, reservior pumping order for inline pumps?

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Arctic Silver Senior
Dec 19, 2000
Stool and Dr. Surlyjoe have peaked my curiosity, and now Fink adds his thoughts in agreement on the matter. While our three esteemed colleges all use submersible pumps, has anyone tried the radiator, block, reservoir pumping order with an inline pump? Since inline pumps do produce heat, it makes sense. I will plumb my system in this configuration tomorrow, but since I have changed pelts, I will not have any empirical data. Please let me know what y’all think!
Well Colin I to have a submersable pump It is a fuel pump from a 1987 chevy p/u fuel injection system.It pumps a true 25gph. I plumbed from pump to waterblock to radiator to tank. My temps are 31c at idle and never over 44c at load with burn6 or any game I play. system temp is 30c. My mix is 50/50 well water and seira auto antifreeze(the safe kind that doesn't hurt the little animals). Oh yea my water cooler is in another case under the desk. That has to help some.
colin, it is an interesting hypothesis, but i am not sure how much it matters, but yes, it makes so much sense to pump into the radiator then the cpu. Can't believe i never thought of that before.
dunno260 (Mar 24, 2001 12:23 a.m.):
Can't believe i never thought of that before.

Doh! Same here. I have always seen inline pumps go straight to the waterblock. I am concerned about the pump handling the heat. My water temps hit 40 C with a pelt. The only pumps I have found that are rated for such high temps are the Iwaki stainless steel models.
How much heat do the inline pumps give off? I know my submersables produce a good amount of excess heat, but I admit ignorance to the inline pumps. If they do get hot, then there will be some transfer to the water but more importantly they will add heat to whatever they are contained within, I would presumb that most mount the pump within the case. Wonder what the effect on case temperature that poses, especialy if they are mounted in the incoming air stream (lower front of case).
If I use the bypass switch and let my pump run overnight without the rest of the system on, the water temps will be about 10C over ambient.
Here’s the results in my system. 6 C higher idle temps when pumping to the radiator first instead of the block. No idea why. If you want to see my system’s layout, here is an old pic.

It looks like your running 2 pumps ,,Is that right?? if so,,whats the other one for? just wondering
Now you have me curious. As soon as my Iwill comes back, I am going to try the different configuration. 6C is quite a difference. I must also wonder, though, whether mine being a mostly external system will affect results. Also, though I don't have one, I had been given to understand that inline pumps, for some reason, did not add heat to the system, whereas the submersibles did. I'd like to find out which is fact.
surlyjoe (Mar 25, 2001 10:02 p.m.):
It looks like your running 2 pumps ,,Is that right?? if so,,whats the other one for? just wondering

Nah, that funny looking foam covered thing in front of the pump is a drain and bleed valve. It makes system maintenance simple.