Worklog: High-Reliability Water-Cooled PC

To the best of my knowledge, this will be the first water-cooled PC using 100% aerospace-quality stainless-steel braided hose line, 100% SAE flare aircraft-aluminum anodized full-flow hose ends and fittings.

Jump to Worklog Updates below

PC Dominion Water-Cooling Axioms

This PC will align with certain best-practices that I've determined over the course of building numerous water-cooled PCs over many years; namely:

• Internal radiators are sub-optimal because they have to rely on hot air from inside the case.  When at all possible, an externally mounted radiator should be used.
• Worm-drive clamps are a pain and should be avoided.
• Tygon tubing is a pain and should be avoided.  It may be more reliable than vinyl tubing, but it's so soft that it's difficult to obtain a good seal on hose barbs using any kind of clamp. It also tends to collapse and restrict water flow unless combined with plastic spiral spring wraps, which are an added hassle.
• Half-inch tubing is overkill and too large to work with comfortably. It obstructs access to PC components. I've cooled quad-core overclocked CPUs plus video cards with 3/8" tubing and a good pump. If you really think you need 1/2" tubing, you probably need a second loop of 3/8" instead.
• Water-cooling Intel north bridges is not necessary, though it's definitely advised for nVidia north bridges.
• Air-cooling should always be used in conjunction with water-cooling to cool the RAM, Intel north bridge, and VRMs. Some people have used water blocks on their RAM and VRMs. I don't advise this; it makes the whole system way too much of a complicated maze of hoses, and impossible to service.
• Plastic drive-bay reservoirs are noisy, and require you to tip the PC backwards precariously to top off the coolant. Instead, use a Danger Den Fillport, with or without the Fillport Reservoir. Alternatively, an internally or externally mounted metal reservoir can be thick enough to dampen water sloshing noises.

Design Goals for the High-Reliability Water-Cooled PC

Some attributes and design goals of this project:

• All hoses will be AN -6 stainless-steel-braided aircraft hose with full-flow hose ends (AN -6 is functionally equivalent to 3/8"). Note that SAE AN flare fittings use a 37 degree contact surface for 1500 psi capable seals without the use of tapered threads or Teflon tape.
• No hose barb fittings will be used anywhere in the system.
• No plastic hose or plastic fittings will be used. The heavy anodizing on aircraft-style aluminum fittings and hose ends should resist galvanic corrosion with copper in the loop.
• The radiator will be at least 3x120 and will be mounted externally.

The Current Prototype System

Here are some build shots of the prototype, which is similar but uses standard vinyl tubing. Click on images for larger views.

Case Choices

The current front-runner for the system case is the Cooler Master Stacker RC-810.  The case needs to be large, to allow attachment of the big external radiator as well as to mount the pump and drives, etc. internally.

Other cases considered:

• Cooler Master Stacker STC-T01. I use this case in my current main water-cooled system which is a similar design to the HRWCPC project, but with vinyl tubing. Its optional 300mm cross-flow fan (squirrel-cage blower) is very handy for keeping motherboard components cool, but it lacks the dual rear 120mm fans of the 810 model.
• Silverstone TJ07. A beautifully designed case but unfortunately the bottom area is not large enough for an unobstructed 3x120 radiator.
• Silverstone TJ09. Another nice case but the bulky hard-drive cooling system, combined with a bottom power-supply mount, leaves little options for water-pump mounting

Water-Pump Choices

I have something of a love-hate relationship with the ubiquitous Delco/Laing/Swiftech MCP350/355 pumps, but that's probably what I'll end up using (either with the Alphacool replacement plexi top, which I have on hand, or a dual-pump adapter). The Danger Den Mag II takes G1/4 fittings directly but its flow rate is much less than the Laing. Other major pumps use hose barbs which I refuse to allow in this build.

Alphacool high-flow tank top for Delco/Laing/Swiftech MCP350/355 pumps - courtesy Jab-Tech.com

Radiator Choices

This comes down to 2 options: the Thermochill PA120.3 (which is superb with low airflow, and it's what I use in my current main system) or the Black Ice GTX 360.

• Thermochill PA120.3: 61mm thick, G3/8 threads (this is annoying since I'll have to use a G3/8 to G1/4 adapter, a.k.a. an Eheim pump input adapter fitting)
• Black Ice GTX 360: 55.7mm thick, G1/4 threads (allows direct use of my G1/4 to AN -6 fittings, but doesn't perform quite as well as the Thermochill). One small bonus is that it's available in blue which matches the blue-anodized aircraft fittings.

Water-Block Choices

I recently bought the new Koolance 330 CPU block, because I thought I couldn't use a Swiftech Apogee block. Swiftech has been using a bizarre thread style called NPSM and there are no adapters in existence to fit. Luckily Swiftech just released their new Apogee GTX which finally gives in to the trend and uses G1/4 fittings.

The Koolance 330 is a very low-restriction design, with an excellent mounting mechanism, and I might have ended up using it anyway, except I was just testing a fitting with it and its plating came off. Just peeled off in a big 1/4" wide strip like old paint. This does not inspire confidence -- so I'll be sticking with the Swiftech Apogee GTX.

Swiftech Apogee GTX exploded view - courtesy Swiftech

Worklog Updates

Mar 26, 2007

Received the essential G1/4 to SAE AN -6 blue anodized aluminum fittings from Kinsler Fuel Injection. Nice folks at Kinsler, although like many in the automotive world, they haven't quite joined the 21st century. Their catalog is a PDF of page scans, and you have to call to order.

These fittings are not cheap at $10.80 apiece plus $5.00 for each sealing washer, but they're quality stuff. The sealing washers have a black composite ring on the inside which is thicker than the washer itself and provides a tight seal for the fitting.

Also in the pic below are some G1/4 spacer rings I got from Petra's Tech Shop. These are flat metal on one side, and have a recessed O-ring on the other side. Many PC water-cooling items, especially water blocks, have very shallow threads so I needed to be sure I could mount the Kinsler fittings in any device I wanted to use.

The Kinsler fittings do indeed fit all of my G1/4 items, so it looks like the concept is proven! Time to order the hose and hose-ends from Summit Racing Equipment.

I'm also looking at this sweet power steering reservoir from Summit Racing:

This baby is 7-1/4" by 2-1/4" and has 3/8" NPT threads on the inlet & outlet. It's baffled internally so it would help reduce sloshing noise and foaming. Both ends are sealed with O-ring caps.

Apr 05, 2007

A lot of the hardware has arrived, including:

• The braided hose, hose ends and fittings from Summit Racing
• The power steering reservoir pictured above from Summit Racing
• 3x120 Black Ice GTX 360 radiator, 200mm Antec "big boy" fan, Silverstone drive bay adapters for front-panel units, and Silverstone 3x fan speed controller, plastic flexi edge molding, Swiftech Apogee GTX waterblock, blue fan grille and red screws, from Performance-PCs.
• 3 of the Silverstone 5-1/4" bay HD bay coolers, another Intel D975XBX2 mainboard, Silverstone 3-1/2" bay adapter, and DVD drive from good old Newegg (picture below).
• Alphacool dual Laing pump adapter and mounting bracket direct from Alphacool Germany (expensive shipping, but it arrived instantly, and the bracket isn't for sale anywhere in the US that I know of).

Here is the Alphacool dual pump adapter which mounts 2 of the Delco/Laing/Swiftech MCP350/355 pumps for reliability and enhanced performance. The G1/4 to -6 AN fittings are installed on the dual pump adapter. Only one pump is installed in the pic, to show the internals of the dual pump adapter block. I've included the original pump top in the picture (lower right) for comparison.

The Black Ice GTX 360 radiator and Swiftech Apogee GTX waterblock, both with Kinsler G1/4 to -6 AN fittings installed.

The new Stacker stripped down for modification. Photo on right shows how I've removed the back panel of the power supply bay (see arrow) to allow longer power supplies (e.g. PC Power & Cooling 1Kw).

I never use any equipment until it's been fully inspected by my assistants, Dia (short for "El Diablo Blanco", left) and Winston (right).

Test fitting the drive-bay devices. These Silverstone CFP51 3-1/2" HD bays are snazzy and perfectly fit the gently rounded front contour of the Stacker. The Silverstone triple fan speed unit will control the three drive bay fans. I have a Cooler Master black aluminum faceplate for DVD drives which I plan to use since, as you can see in the pic below, a normal "black" DVD drive is not very black.