I'm running a pro-tech pipe single cool line from pump with a t at manifold. I'm trying to get the pipe hot but keep engine warm. I put a by-pass line installed at rear head exit. Plus I installed a valve to restrict water to head pipe, this allows most of the water to be dumped to the pisser from rear of head. This set up works well to get pipe hotter but I noticed how hot the head became. My questions : 1- should I run true dual cooling to assist with cooler engine temp? 2- if I restrict too much water to head pipe does the heat from exhaust back up into engine? It would appear so with my experiment. I was wondering if dual cooling would help or am I creating unwanted heat in engine by getting head pipe to warm. I'm trying all this because this pipe takes too long to get hot, ANd who doesn't want a hot expansion chamber.