Water temperatures looks very good but makes no sense in combination with the CPU temp in my opinion. It should be much lower if your water temperature is that low. Have you checked that the block has proper contact to the CPU?

Hey,

i have an i7 920 @ 4,2 Ghz, vcore is above normal ( not sure about the exact voltages )
Idle temps of the processor are 1-2 degrees over water temps with a kryos HF.

@ 27 degrees water temp i get a cpu temp of 53 degrees max after 8 hours of prime 95.

So i would say that your temps are way to high as my load temps are only a few degrees higher than your idle temps.

I suggest that you have a problem with your cpu cooler.
Check if your cpu cooler is mounted correctly, is there enough pressure on the cpu cooler?
Did you use not enough or maybe too much thermal paste?
What about the flow in your system? I get around 95 liters/hour.