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Getting a good in-line pump / waterblock

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Senior Member
Dec 18, 2000
Amsterdam, the Netherlands
I am preparing to go watercooled, already got myself a radiator and some tubing. The radiator is from a '77 ford heater (160x160, aluminium). I've got some 1/2" and some 3/8" tubing, no waterblock yet but a big piece of aluminium is available, so I probably end up making one myself. I think I'm going to make it like the one I've seen at cool-computers. Any comments / suggestions?

Main problem is I don't know what pump to use and where to get it. In-line seems better to me, because the setup requires no waterbath and there is no heat-dump by the pump. How much GPH do I need for my setup with 1/2" tubing and the radiator? And where can I get a good pump. Tried some garden-centra, but the pumps are very large and expensive. Maybe I use the 3/8" for another cooler for my Geforce, cooling parallel.

Marry Christmas to all of you!
Right, this is the third time I've tried to reply - damn netscape KEEPS crashing. Here goes:

Firstly, well done moving to watercooling (even if you haven't finished yet)! I've just finished my first watercooled rig (inline), it's great fun, not to mention cooler! That old heater core should serve you well - Jeff swears by them, I think he did an article on restoring old heater cores on the frontpage - check it out. Even If you decide to make your own waterblock, I suggest you get a holddown from dangerden, I've got it (along with their waterblock and radiator), and it's a better design than anything you could ever make yourself (I'm not knocking your metalworking skills, it just is that good).
If you're looking for a pump, just do an internet search for aquarium stores - you'll get a *few* results, but it shouldn't take too long to find what you want. I'm in the UK, and it only took me about an hour to find somewhere suitable ( www.creamston-aquatics.co.uk if you're interested, but I guess you're in the States). I know Tom Leufken has a nice looking 200gph pump, but I think it only has 3/8" fittings - don't worry too much about finding the right sized fittings, it should be pretty easy to modify. My pump has a 3/4" inlet and a 1/2" outlet, and I'm using 3/8" tubing, but some copper tubing and a load of epoxy sorted that out :)
Just go for a 100-200 gph - I seem to remember most aquarium ones were rated a fair bit higher, hence the higher cost. Make sure you get one with a suitable max head rating (the height the pump can lift the water - give yourself enough headroom here to make sure you have enough power. Inline's a good choice for a fully contained system - mine fits nicely in my full tower case, keeps my tbird at 39C max with 1.94V. Have fun!

PS - just had a thought, try and wire the pump up so it switches on with the computer - I forgot to switch mine on this morning, thankfully the comp crashed when it got to 60C and I realised. I'm going to use a relay like in Joe's article on the frontpage, looks easy enough.
Internet sales etc.

Actually I live in Holland, not in the USA. Anyway, thanx for the tip to buy online. I've seen some really good pumps on Internet, so I know what I'm looking for. See if I can get anything here to save shipping costs, but it will be hard. The struggle for watercooling is long ;)

Some one else around here with watercooling experience, i.e. tips?
Be sure to ask around about optimum coolant recipes. I use 10% anti-freeze 20% alcohol 70% distilled water. This mixture has served me well. It's important to use a little anti-freeze, because this prevents corrosion. I find that Alcohol really helps lower the CPU temps too. Some people are using a product called "water wetter", this product increases waters heat carrying capacity by reducing the waters surface tension, which releases the tiny air bubble in the water. Alcohol naturally has a lower surface tension (that's why it evaporates so quickly), so it can also be used with similar results. Don't be afraid to try different mixtures to find which works best in your rig.

Just as I side note: I do swear by heater cores, they have more surface area than any commercially available radiator of their size. They were made to remove heat from water in order to heat air.
PS - just had a thought, try and wire the pump up so it switches on with the computer - I forgot to switch mine on this morning, thankfully the comp crashed when it got to 60C and I realised. I'm going to use a relay like in Joe's article on the frontpage, looks easy enough.
I agree. Not running the pump almost means certain death to an OCed CPU. I don't have a relay in my box yet. I hot wired the power button (AT) so that the box is always on. I have to turn the power-strip on to turn the computer on. Since my pump and computer are both using the power-strip my pump turns on at the same time.
hubba hubba hubba ...

Jeff Evans (Dec 26, 2000 07:09 a.m.):
Does Holland have a 220/240V power grid? If so http://www.leufkentechnologies.com has what your looking for. 200GPH 220/240V inline for only $28 (USD).

In holland we have 220/240V, so the leufkentech. solution is a good on! I didn't know their site, they've REALLY got some need stuff over there 8) . Maybe I can get some inspiration from the other stuff they have there. The pump you advised me looks really need! It is real small and the tubing fits direct to the pump. They say the tube out is 1/4", isn't that small or is it OK? I've read at the homepage it is best to use bigger tubing (1/2" e.d.) or will smaller do? how small ? I can still change you see :)

About the liquid, I think I'm going to use the same as yours. I'm student chemist and know a little bit more about water. The high surface tension from water is caused by H2O being highly polar. Mixing liquids with different polar properties disturbs the (in this case attractive) interaction between molecules. Alcohol is not so polar (which causes it's lower surface tension) and interferes with the water, so surface tension is lowered. So alcohol is a good choice for me (of course!), since I can get it very easily and don't know any dutch word for "water wetter". I like the clear fluid, maybe I add some little lights in my tubing later, because I've seen some very cool effects on the internet about it, not rushing it. Also very good against the bacteria, make 'm go drunk!

Thanks for the advice!

p.s. If I have some other kind of booze to cool my K7, I will let you all know. Has someone tried beer yet? Must do very fine, except for some froth.

Greetings to Fink, another chemist in the OC-scene.
Size DOES matter!

Now I am talking about tubing, I want to straighten one thing out. By 1/4" (example), do you (and every body else) mean the outside diameter or the inside diameter??? Just wondering..

Yeah, these heater cores rule! I've tested it with hot tap water (I was cleaning it, wondered why not test it's capacity immediately) and a 120x120 fan, not much CFM (brand unknown). Breathing out hot air and cooling the water VERY good (sorry, no temps available). Now see how it handles my athlon 25micron ;)
When we talk about tubing we are talking about ID(inner diameter) tubing unless OD is specifically mentioned. I for example use 3/8-OD tubing stretched over 3/8-ID barbed nipples. This works great for me because I don't have to even bother with hose clamps.
hey Mr. Murphy student chemist dude . . . .

What do you think methanol will do for cooling? I just realized that I have several barrels of it in the barn (fuel for the race car) and was wondering if you knew anything about it's thermal conductive properties.
Methanol etc.

I think methanol can aid you in keeping your cpu nice and cool. I've looked for the heat capacity of some additives. All of them lower the surface tension of water, are soluble in water and kill your bacteria or whatever it is that lives in your watersetup. You don't need much methanol to decrease the surface tension of water, 10% should be enough. It also kills the algue more effective than ethanol (i.e. it is more toxic). I would advice against more than 10%, the methanol stinks, makes water (like the other additives) conductive and is toxic. Water carries most heat, so an exces of methanol isn't going to enhance your cooling.

water: 4,18
methanol: 2.01
ethanol: 1.91
acetone: 2,73
(this are heat capacity in Kj /K /L)

WARNING: acetone is used to solve about EVERYTHING, including most plastics, which means your tubing/pump! Some plastics are acetone resistant, most not, so test first!!!

This is just to say how much energy the liquid has to absorb in order to increase 1 degree celcius per liter. It's easy to see why water is such a good coolant, takes up much heat from your waterblock.

You also asked for the thermal conductivity. I don't know much about it, but I think it doesn't matter as long as there is a good flow throught out your cooling setup, so the liquid mixes and the surface tension is low (increased risk of leaking!).

Maybe you could give it a try, of course with a little bit of corrosion inhibitor / anti-freeze. Just as a precaution test a little bit of your tubing first, see if it resists methanol, but it should be no problem, it is practicaly the same as ethanol.

I've done no corrosion search yet, but I think that methanol and ethanol will be ok. Acetone should be ok with metal, but look out with plastics! It solves most organic stuff, so NO way for bacteria :) .

Maybe when I get the stuff that can handle water-acetone, I give it a try. Acetone is very easy for me to get, at the university we chemists use it to clean our glass equipment (like I said, it solves almost everything).

FunFact: acetone is used to cool some of the artificial ice-skating rings, believe me, cold as ice.

Moral of the story: You don't need as much methanol as ethanol, becaus is kills algue more effective and holds less heat than water. I recomment 5-10%

Succes, hope it is usefull ;)
Dean, I've got the exact same card as you do, and I probably have lower temps also. What are you actually using to overclock, such as the software etc...
Why don't you use a campers water pump? It's cheap and reliable!

The Master (Dec 27, 2000 03:56 p.m.):
Why don't you use a campers water pump? It's cheap and reliable!

I had never thought of this before, but is seems great to me! As soon as the camping shop is open I will run to it so see what they've got! I asume you mean the pumps they throw in their water tanks in caravans etc. The only thing I'm afraid of is that they sometimes can make much noise. My parents have a caravan, so I know how it sounds. Maybe they even have in-line pumps overthere...
The Master (Dec 27, 2000 03:46 p.m.):
Dean, I've got the exact same card as you do, and I probably have lower temps also. What are you actually using to overclock, such as the software etc...

I'm not an native american, so I may have gotten this wrong, but who do you mean with "dean", is that me? What cards do you mean, I can't imagine you ment that GeForce I mentioned in the first article. At the moment the only thing I use to tweak it is Asus tweak utility, because it came along with my V6600 video card. I hate the standard cooler on it, you have to clean it once a month because of dust between the fins. I use a nr. 10 painting brush, works great, but when I get my athlon 500@750 watercooled, why not cool the geforce too?
MikeL (Jan 07, 2001 08:53 a.m.):
What is better? Aluminum or copper?

Copper is way better! Almost twice the heat conductivity capacity of alu. Problem is that copper is more expensive and is heavy-weight. Copper is the more easy to handle than alu in fabrication. This was what you were lookin' for? Here it is...
another thing where can I get a better pump at? I got one yesterday and it only pumps up to 18" high and thats not very good anywhere else I can get it besides online?