Maximum PC

Well, a few years ago I built my own PC with water cooling using among other things a Swiftech Apogee GTX Waterblock for my Core 2 Duo proc. I completely pull apart the system every 18 months to clean everything and when putting it back together I ended up over-torquing the waterblock to the mobo. The mounting screws and spacers don't come to an absolute stopping point and basically I ended up ruining the mobo (there was a bulge on the back side where the cpu sits due to too much torque being used - d'oh).

Being my only computer I paid an arm and a leg for an identical mobo and am running with the stock cooler ATM - the water block is handing out of the side of the case like the intestines of so many road-killed deer. I corresponded with Swiftech about there being no absolute stop on their mounting hardware, you can keep tightening until you end up crushing the CPU or bending the mobo or both. I also complained about the screws seeming to be a bit "soft" and stripping easisly. They sent me new mounting hardware and screws. I thanked them and in their reply they told me that the Intel spec for mounting the Core 2 Duo is 43 lbs. +/- 10 lbs.

I really do want to get back to water cooling again but am scared as all heck that I'll "bulge" the mobo again. So two questions:

1. Do they mean ft./lbs. ? I assume yes but I wanted to check.

2. Does 43 ft/lbs seem a bit much to anybody?

I have a manual torque wrench (NOT pneumatic) that I've used in the past for car repairs and it does go down to 10 ft/lbs but even 33 ft/lbs seems like a lot of pressure to put on something that's mounted to relatively fragile PCB.

Any advice here?

This is how I do mine (EK Supreme LT):

Tighten all the screws uniformly until I notice the mobo begining to bend, then back off by half-turns until it is flat-ish again. Usually this feels PLENTY tight, and you will know if its too lose if your temps are higher than normal. Slight warping is not big deal, but yeah you dont't want to go all the way down on some blocks (mine included).

FSM states 80-100 ft/lbs for the lug nuts on my 2000 XJ (Jeep Cherokee).

1/2 that for a CPU? damn.

Bending the mobo too much is a bad thing. I'd check your temps under full load at several different tightnesses, figure out what you're comfortable with. If temps are too high, tighten it down a bit. If temps are ok and you're not bending the mobo, then i'd say that you're probably ok. See how low you can go, but I have a feeling that once you reach a certain torque, you won't see any dramatic improvement in temps. The hard part is to find that torque...43ft lbs seems pretty dang tight though... I would start where it starts feeling snug, and then keep tightening until you don't see any improvement in temps, or start bending the mobo...

Yeah, I figured it would be too much. I'll have to do a little at a time. Heck, if I don't tighten enough the system automatically shuts down. So a little caution won't hurt.

Thanks for the advice.

It's INCH pounds which is usually a 1/4" torque wrench as the 3/8" wrenches are in FtLbs. Forty InLbs isn't a whole lot and is usually snug + 1/4 turn (kinda like an oil filter). That shouldn't bend the board unless it's a 3 layer board or less. Most water blocks I'm familiar with just have springs and the brass nuts just hold tension on them, which the Apogee I used had as well. As long as you don't fully compress the springs then the specs should be inline.

The metal backing plate is always a good idea too. With the Lexan pieces, they tend to bend as the piece heats up. Here's a DD Lexan s775 backer that's bent and allowed the 6-layer board to bend too.

The backer should be the main support and keep the board from bending. If the backer bends, it's not doing it's job.

I lost the pic, but have a pic of a Foxconn ELU board bending just from a coolermaster V8 aircooler even with a metal backing on too.

Snap-on Tools has a torqu screwdriver (qdriver3) that is good for working on electronics (or plastic dash work) where you need to make sure you don't call over small inch pound settings. Oh course if you snug them up (not crack them down) most of the time that is all that is needed.

It's definitely in/lbs as mentioned. Especially considering that 41 ft/lbs is the standard torque spec for a 10mm Caterpillar bolt and 35 ft/lbs for a 3/8 in. bolt!