This is my first instructable, I hope you find it useful! What I found this way to be the best way is not having to have a special bracket made, most heat sinks (besides the old Pentium 4's) that are made this way can still use the original bracket.
Things you will need:
-Stock heatsink (I am using the original heatsink that comes with an AM2-AM3+ AMD Processor) w/ at least 3/8" thick solid layer of material.
-Metal hacksaw, sawzall, or bandsaw
- 2 1/4 or 3/16 NPT Barb fittings (Preferably made from the same material as the heatsink, to prevent corrosion)
- 1/8 drill bit and 1/4 drill bit w/ drill.
-Vice or C-clamp to secure with.
-Sharpie or any other permanent marker
-JB Weld, or any other similar epoxy.
NOTE: This can be very messy, and involves a lot of metal particles. Use personal safety protection and be aware of the metallic dust and debris that will be around. When washing exposed skin that is dusted in metal particles, rinse what you can first, then wet wash cloth or paper towel and dab, not rub exposed skin. Rubbing and wiping can cause flake to embed into skin. As for eyes, you should be wearing eye protection, if not and you get debris, DO NOT RUB EYES AND BLINK AS MINIMAL AS POSSIBLE. Rinse eyes ASAP.
Step 1: Marking to Cut
1. Remove any fan and mounting brackets.
2. With permanent marker, mark a straight line just below where the cooling fins start on the block.
*If heatsink is tapered like the AMD AM2-AM3 heatsink, mark a 90 degree (vertically) line from the top of the bevel to the bottom.
Step 2: Cutting
1. Place and secure heatsink in a vice or C-clamp.
2. Cut along marked horizontal line just enough to let the fins simply fall off. If fins do not fall off one by one, then you are cutting too low, and taking away too much metal and working area.
*For the beveled, cut off sides straight and even, must be block shaped.
NOTE: DO NOT mark, gouge, or scratch the contact surface for the CPU, if you do prepare to have fine grit sandpaper.
Step 3: Marking to Drill
1. Mark where you will be channeling flow with the drill bits.
2. Remember, cut in straight; its okay to drill all the way through horizontally into the block. The exposed holes (except the barb fittings) will be plugged off in the very end.
3. You can make any pattern of flow, just keep in mind of flow resistance and restriction. Just as long as there is A-B flow.
Note: Think of it as a pipe game.
Step 4: Drilling.
1. Secure the plate/block.
2. Start drilling EVERY bore with the smaller bit (1/8"). The main flow bores will be step drilled after with the 1/4" bit. The smaller bores guide the larger bit. DO NOT DRILL OUT FITTING BORES YET.
3. After the channels have been drilled out, use the same process for the fitting bores using the step process. DO NOT DRILL ALL THE WAY THROUGH VERTICALLY.
4. With pressure, slowly screw in the barb fittings until they start threading themselves in.
NOTE: Though it is not needed and I didn't use one; a thread tap will make threading easier.
Step 5: Final: Cleaning and Sealing
1. After the barbs are pressed or threaded into their respectable positions, apply JB Weld or similar epoxy around the bottom edge of the fitting to seal up any potential leaks at the threads. Let dry completely,
2. After epoxy has hardened, take the 1/4" bit and re-bore out the exposed, excess threads of the fittings. This will allow the fittings to be flush with the bore allowing unrestricted flow at said fittings.
3. Clean the block out by running water through it, and blow air into it.
4. Seal off every exposed end of the bores with epoxy.
NOTE: Its best to start with the smaller diameter secondary bores (1/8"), so you can bore out the excess epoxy with the 1/4" bit.
5. Let harden.
6. Run water and air through at pressure and speed to test for leaks. Apply epoxy where needed.