[hara]

first you have to check out whether the brass and the copper are going to make a battrey effect, i'm not an expert in this region but the only thing that i know is that it is better not to mix two types of metals in a setup like this.

Brass is an alloy made of copper. Copper and brass mix well in watercooling. This can be seen by the amount of people using copper blocks, brass heatercores and barbs. Secondely, the #rotor method is quite restrictive and Northbridges don't produce that much heat after all. So if this block is going to be put in series with the loop, the #rotor method should be avoided. Northbridges could be even cooled passively so making a high performance block for a NB is useless. I consiter lucas'z design more than enough.