I just realized that I could update that to help some out with the RBX/TDX nozzles a bit – I need to go back and run some tests with different nozzles with different pumps and breakdown the nozzle performance based on the flow and head pressure of the pump. A weaker pump would do better with the wider (less restrictive nozzles). Unless the CPU block is the only block in the loop, a pump with low head pressure would likely loose performance with the more restrictive nozzles. It would be interesting to see where the performance drops off or really kicks in with each particular nozzle. I suspect that is an update that will have to wait until my new thermometer arrives.
you can get a large rubber washer like that at plumbing stores, DIY stores and some autoparts stores.
I like the fillports as well – I think I will be incorporating them into all of my future H2O builds as they make filling so much easier. you don’t have to fight with a tube while trying to pour coolant into the system.