Part 8 - Project Blue Dragon – Water-cooling and Case Mod Build Log

Problems Encountered Along the Way:

I'm hitting a few little snags along the way through this computer build, so I'll explain a few here.

The CPU power cable that came with my Corsair power supply, is too short.

I managed to get hold of some of these though (ATX PSU connectors):

ATX PSU Crimp Connectors

And some equipment wire:

Wire 0.75mm

I was going to have a go at rewiring the cable, my thoughts being that I could make a nice neat job of cabling. However, I got the cable home and noticed that the existing cable is 18awg and the cable I'd brought is a metric size, 0.75mm rated at 6A, this falls somewhere between 18awg and 19awg. I checked out a comparison table and 18awg is 0.82mm. I wasn't sure if this wire would be sufficient, whilst working out what to do next one of the forum members from Overclock.net pointed out that my Obsidian case actually comes with an extension cable for the CPU, problem solved.

I was going to buy some pre-modded cables i.e. for PSU connections, graphics cards and the main 24 pin power cable etc but then decided to have a go myself, so I got hold of some heatshrink and some nice cable braid.

Cable Braid

Cable sleeving:

So I've been spending my evenings sleeving all of my PSU cables. I didn't actually realise what a time consuming activity this was until I started out. The first couple of attempts were rubbish so I stripped off three lots of braid and started again, then I got the hang of it.

I've now managed to get all of my PCI-E cables done and I've now finished including the 24 pin PSU cable. Now that I've started I also want to sleeve the SATA and all of the other cables.

If I get time I'll publish a cable seeving guide.

Sleeved PCI-E Cables

Sleeved PCI-E Cables

I got some more feedback from a fellow water-cooler on the technology forum that I register with; Overclock.net, the feedback from one of the forum members was as follows:


"I've been thinking about your plan for your loop. I think you should consider rerouting it to the following:


Reservoir - Pump - CPU - 240 Radiator - GPU (in parallel) - 360 Radiator - Reservoir


here's the reasoning:
Those D5 pumps have a coolant temperature limit (if they are Koolance 450/S pumps it's printed on the label); I wouldn't dump hot coolant into them. I know it won't really matter that much once the coolant equalizes under high loads, but it will be better for pump life on idle loads and it will keep them cooler longer until the equalization comes into effect.


You have the head pressure to maintain the flow, so use parallel on the graphics cards; you'll get a more consistent, lower temp on both cards rather than the 1st card always raising the temp arbitrarily on the second card."

So I fiddled with my initial plan/sketch, and came up with the following:

New Layout Drawing

New Layout Schematic

I decided that this looks better than my original plan and the reasoning behind the loop order makes sense so I have changed the loop order as suggested.

Other Problems:

Another problem; when I tried to fit my Phobya fan grill and 360 rad in the top of the case I found that when I tightened the screws through the fan grill to the rad it was causing distortion of the fan grill.  The reason for this is the recess in the top of the case.

Recess in Top of Case

So I spend a good part of a whole day making up some spacers from a piece of 5mm polycarbonate.

On the Saturday I was going to start installing part of my loop but I encountered another issue with the positioning of my top fill port. I have my reservoir installed one bay below the front I/O panel and switch assembly.

Position of Reservoir in Front Panel

I've installed a fill port in the top of the case, my plan being to ease the filling and bleeding of the system. However, the res and fill port are very close to each other.

Fill Port Viewed Inside of Case

With the fittings I currently have I was struggling to connect the two together. I need a couple of 1/4" Thread Rotary Elbow Fittings, these should solve the issue but it means I cant continue with what I wanted to until I get some extra fittings.

I did manage to do a little mod on the CPU-370 backplate that was a bit close to one of the motherboard heatsink fixings.

Before Modification

CPU-370 Backplate Modified

After Modification

I've also tested out the TIM contact on the CPU-370 and installed the water-block.

TIM Contact on CPU

TIM Contact on Waterblock

Lovely Clean Shiny Surface of CPU-370

Installed on Motherboard

Installed on Motherboard

And finally: Just a little detail, I installed some thin foam with some strong double sided adhesive tape to isolate the PSU from the support rails in the bottom of the case, just to reduce any vibration.

PSU Vibration Insulation

My friend on the Overclock.net forum made another suggestion regarding the way I had fitted my fill port in the top of the case:

"This probably won't work as expected. It'll most likely trap air in the fitting and cause you a headache in the fill process. top offs it won't be bad, but it will during the initial fill. Maybe try to get a snake rotary and do a hard attachment to one of the top fill ports in the reservoir. Any bend greater than 45 degrees will probably cause an airlock. Preferably the straighter the path the better."

I've messed about with a few different fittings to see if I can do a hard attachment but there just isn't enough room. On hindsight I should have positioned the fill port differently, I'm a bit annoyed at myself as I thought I had planned very carefully. However, I can just about get some tube in there and probably get one of those Phobya angled things to make a low restriction bend.

If as my buddy suggesting this setup will make filling a bit difficult I'll just have to live with that, this is what it looks like:

Viewed from Inside Case

Viewed from Front of Case

At one point I thought I might be able to rotate the 360 rad so that the ports would be closer to the res but there just isn't enough room.

He also commented about the orientation of fans and whether they should exhaust or intake, this is an interesting comment. During my planning I asked a lot of questions on forums about my initial plan and the consensus of opinion was that the top fans should exhaust and the bottom fans should intake, the reasoning being that hot air rises.

I have considered adding water temperature and flow sensor in the loop, not because I think it's essential but just so I can monitor temps and flow. An update on this in a later part of my build log.

Build progress:

I finally have almost everything in the case but I'm holding of with filling the loop, as I suggested above I may install a couple of temperature sensors and a flow sensor along with a monitoring interface but I need to do a bit of research on this. This is how it's looking so far.

Nice, but the BluRay Player Looks Crap in that Colour

Looks Like a Professional Build :-)

I'm not particularly happy with the colour of the BluRay drive but don't know what I can do about this, I suppose I'll just have to live with it.

I also managed to get the 360 rad rotated so that the input and output are towards the front of the case, this has tidied up the tubing somewhat. I have also changed the loop order from my original plan on the advice of an Overclock.net forum buddy who very kindly suggested the following alternative.

Reservoir - Pump - CPU - 240 Radiator - GPU (in parallel) - 360 Radiator - Reservoir

The reason for the change is that the Koolance PMP-450 pumps have a temperature limit, this new loop order prevents dumping hot coolant into them. I have the head pressure to maintain flow, so I have setup the graphics cards in parallel as per bane-o's suggestion; in theory I should get a more consistent, lower temperature on both cards rather than the 1st card always raising the temp arbitrarily on the second card.

Build log pages: 1..2..3..4..5..6..7..8..9..10

Thanks again for looking and as always comments are welcomed, you can leave comments below or on my Blog Home page, here.