I did some testing today.
The aluminum heatsink, while getting quite hot, did basically nothing to lower the temperature of the pump or the temperature of the water.
Putting a fan under it as seen below, lowered the temperature of the pump by ~8 degrees, and the actual water by ~2 degrees.
No radiator is attached to this loop yet.
http://www.atomworks.com/public/boar...ump80mmFan.jpg