Just an update, The Corsair 110i 280mm does fit into the Fractal Define R4 in the front. You will have to remove all HD bays. To make it work without modification, you need to have in push/pull or push. With doing so, only 2 screws line up on the front filter. I did mine as pull with two 140mm shrouds in order for the radiator to be connected as the actual radiator is too big for where it mounts the fans. You will need to set radiator inside but mount it by screwing the outside screws while it sits inside. You will not be able to open the filter door all the way due to size but just enough to be able to remove filter for cleaning. I can provide pictures if you want.