A full open-loop water cooling setup. I was told by most that a 280mm rad wouldn't fit in the front of the Fractal Design Define R4 without major modification or mutilation. Well, I managed to do so without doing any major damage to the case. In fact, besides the drill holes and some paint (filed the burrs and then painted the bare metal) it can go back to normal without any issue. I can even access the front fan filter still! The front fan tray assembly has posts for aligning the 140mm fans and I didn't even have to modify those. Although, doing so made removing the rad/fans from the case quite the chore. I had to use 1/4" tall aluminum spacers between the tray and fans to give clearance for those unmodified posts. So, to thread the screws I have to go through the tray, through the spacer, through the fan, then finally into the radiator and do that for 8 screws. I may eventually drill for some reinforcement screws since the weight of the rad is enough to overpower the retention clip. I custom-made the pump bracket. The holes it uses don't interfere with the PSU+Fan filter on the bottom. I haven't looked but I think there's even clearance for the lower drive tray assembly if I use the offset position (which sits partly where the 140mm fan is). I made the pump to CPU block line a bit long because I plan to add a GPU block when I upgrade it. The 970's getting a bit long in the tooth as the saying goes. I also have the conversion adapter and brackets for AM4 (Ryzen) since I'm fairly certain I'll be upgrading to the Zen 2 Ryzens when they're released. On the 6600K@4.7GHz (1.408v VCore, pictured below) the temps are 22°C idle and ~77°C on the hottest core. I lost the silicon lottery on this chip. I don't even think delidding will save it. To go from 4.7GHz to 4.8GHz was 1.408v to 1.44v and it still wasn't very stable. Even 4.75GHz, which I was at for a while, needed 1.424v+ to be stable. I don't want to fry this just yet so I opted for longevity with 4.7GHz@1.408v. On the X5660@4.4GHz I can say that it didn't let me overclock it any more past 4.4GHz. It needs more QPI/VTT voltage to be stable and I'm already at the limit (1.35v). Although, it knocked a good 15°C off the temperature of my ancient Thermalright Ultra 120 Extreme. Here's the final build picture: I opted for white fittings to match Fractal's color scheme (mostly black with white accents). The white zip-tie, which is one of those releasable kind, is temporary. When I do loop maintenance I will be putting in some 90° and 45° bends to move the position of the drain valve and inlet. Some, but not all, of the parts I installed: What's missing from the picture: All the fittings, CPU block (EK Supremacy EVO - now discontinued :open_mouth:), LGA1366 bracket, and the AM4 bracket + conversion plate. Here's the image album if you want to see more pictures, and detail, of the progress of the build: https://imgur.com/a/JjyZJh1 If I were to do it again I would have semi-gloss painted the Rad's frame and then used painter's tape to protect the finish until the build was nearly complete. There's little scuff and scratch marks that I didn't see until it was too late.