if it's getting too hot then flip the fan to blow air into the heatsink, If this CM520 has two fans, then one fan should blow in and the other blow out for a push-pull effect. The air flow through the heatsink should be facing towards the rear exhaust fan or up the the blow hole in the top of your case to eject the hot cpu heat out of the case (depending on your case configuration). Also re-check the install of the heatsink, to be sure you do not have too much or too little thermal paste and the heatsink is making good contact with the cpu, you might have to remove the motherboard to do this
Edit: I re-read your first post:
The fan is the CM Hyper520. Any suggestions
Are you just using just the fan or did you install the hyper 520 heatsink too?
If you only replaced the fan, then pop the intel stock fan that came with the stock heat sink back on it.....How did you remove the stock fan from the intel stock heatsink?