I recently added a hyper 212+ Evo to my rig and overclocked my i5-2500k to 4.2 GHz stable at an offset of -0.024 mv and still get max temps at 71 under full load. Why is this? does the thermal paste still need to set? is it better to have the fan that came with it as a push or a pull fan?
Something is most likely wrong. My friend has his OC'd to 4.8 with only an evo cooling it and gets lower temps than that. I would take it off. Make sure you clean both the heatsink and cpu of the old thermal. Then reapply/reinstall.
*Edit* Make sure you are getting thermal into all the grooves as well
The 212, while offering good performance for a very attractive price is by no means a top end cooler. Here's what I saw on 1st day after building Son No. 3's box with a 2600k and Thermalright Silver Arrow
It's almost ironic that coolers like [Thermalight Silver Arrow] are becoming available just as processors transition to designs that may ultimately render them unnecessary; even overclocked to 5GHz, an Intel Sandy Bridge 2600K doesn't need anywhere near this level of cooling.
In my experience, you should be seeing about 5-7C above those numbers above at 4.2 Ghz ...... 59 - 64 C