Fillport placement - below radiator ok?
 

So, I have been told that having the fillport below the radiator is bad, but how bad.

The plan right now is to have a BIP II mounted horizontally with barbs facing down and a DD fillport at the same level (maybe 1-2 mm above) as the radiator.

I understand this is just about as bad as I could get it for filling/bleeding but just how bad is it and any suggestions on how to solve this problem?

The Rad has to be at the top of the case, serious space restrictions.

Thanks

Twill

Depends on flow - with decent flow it really doesn't much matter where the fillport is - the air will be shifted round anyway. With low flow air pockets will tend to collect in the higher regions.

If you think about it, there are two reasons air will "pocket":
- when the system is off, bubbles that aren't adhered to something with surface tension will tend to rise to a higher point.
- when the system is on, bubbles that are being carried along in the flow (entrainment) may stop being carried along if the flow slows down below some critical speed.

Beats me what you can do about the first problem, other than have a pump that's got enough flow to drag those bubbles back into the water stream when it re-starts - or to make sure all bubbles are gone before you shut things down.
The second one might be a non-problem if, even in the largest cross-section area the flow's still above that critical point (which I don't know) - or if you had a reservoir that slowed the flow enough that bubbles should come out there. Maybe the thing to do, if you're not already planning to use a reservoir, is to try it without and see if you've got a problem - and add one if you do.

Just "thinking it through", feel free to tell me I'm wrong (although a "why" would be appreciated). :)

I should probably tell you the parts to help you think through:

Swiftech MCW6000
Undecided chipset block (probably will be old and cheap) which will change to a GPU block when I can afford a GPU ;)
DDC
BIP II
Danger Den Fillport
lots of tight turns...hopefully no elbows

It;s all going to be 3/8ths although I may go to 1/2 by the fillport to slow things down a tiny bit, but it depends on how hard that ends up being.

it doesnt sound like it's going to be too much of a problem as long as I get the system well bled. Am I right?

Any other thoughts?

thanks

Twill