Advanced - 2

     Ok, so the first thing I needed to do was clean up the inside of the case a little.  With bigger fans, I didn't want anything near the 3" fans.  With that in mind, I swapped out the ribbon cables with ones that I'd taken a knife to.  Big improvement, I think.  As you can see, even with stock cooling hardware, there isn't much room til you start hitting DIMM slots.

          Next thing to do is make sure that the FDP/FEP heatsinks fit on the board.  As you can see, they do, but due to the capacitors on the rear slot, and the MB's chipset heatsink on the front one, the FDP sinks were a little too big.  I shaved the tops off a few fins and both now fit properly.  The front heatsink looks closer to the DIMMs than it really is.  I took some rough measurements and used the same basic process to make a bigger shroud using 3" case fans instead of the standard issue ones.

     Below, are some pics of the bigger fan on the shroud.  I used the same materials and fastened them to the heatsinks with 2 case screws, just like the smaller version.

     I made 1" lips on the large shrouds, and bent them in a little.  I also made the fan area slightly smaller than the fan housing in the hopes that the friction fit would hold the fans securely in place.  It did :)  

     The rear areas of the shrouds are the same on the large and small fan versions.  The only difference is the front where the fan mounts.  There is quite a size difference in the face of the shrouds due to the fans, but the large version still fits and is about a half inch from the side of the case.  Installing and removing the fans is easy, as they just press into the shrouds - no screws.  As mentioned previosly, the FEP sinks and the shrouds are mounted on MSI 6905 slotket adapters.   The shrouds fit quit nicely on the adapters and don't interfere with any components, or prevent me from adjusting the shorting straps to config the voltage, FSB or dual/single mode.  The cut-out area on the back of the one heatsink is to give room for the capacitors on the rear slot.  The caps have about 3/16" clearance now, and should be sufficient as the cool air is being drawn past them, pulled across the heatsinks, and exhausted so no hot air should ever touch them.  The underside of the shrouds butts up tight against the edge of the heatsink so as to minimize loss of airflow over the fins.  I was considering sealing the small gaps with silicon, but decided it wasn't worth the effort.  The only change made to the heatsinks was to drill two small holes with a #36 drill to tap them for the case screws that hold the shroud to the sinks.  They heatsinks can be switched back to their original fans by removing the shroud and screwing the YS Tech fans back on.

     Shroud Results

     My house sits at about 18 to 20 degrees C all year.  With the "stock" heatsinks and fans, the C300As running at 463mhz using 2.1V ran at 37 and 33 degrees with the case off.  The rear CPU runs 4 degrees hotter because it was pulling air off the back of the front slotket, which meant it was using warm air before it even started to cool.  I put the first shroud in and after running RC5 over night, the temp read a steady 34 and 31 degrees.  It would seem that cooling the front CPU reduced the temp of the air being blown over the rear one.  A small bonus I hadn't anticipated.  Unfortunately, I can't locate the old screenshots from MBM but those were the temps.  The first fan fit fine(lot of "f"s), but I decided to move the floppy and HD around - just in case.  The shroud is quite light with the 3" fan in it so I'm not worried about the weight screwing up the slot.  The stock slot 1 brackets hold the whole thing quite firmly and the funky little bracket locks, still work same as normal.  I made the second shroud and installed them both, plugged them in, and checked the temp the next morning.   As you can see, they are running at a respectable temp.  They've been running for almost 2 weeks now and the hottest I've seen it was 30 and 28 degrees.  Before I put the case on, I want to get some forced air going in to at least equal what I've got going out, so until I have time to do that, I'll leave the case off.  I modified the case so the dual fans would blow the air right out the side, and I redrilled some holes in the front of the case.  They were about 1/16" and I punched them all out to 3/16".  Seeing as how this machine has fewer cards in it, it should be easy to mount a couple fans and make some smaller ducts that aim the air up at the CPUs.  It already has the power supply fan blowing out through the top so hot air collecting isn't much of a problem in the mid tower.