Hello everyone, I've got a 1996 civic hatchback with a b18c1 GSR motor. the engine has been bored over to 84mm and has closed deck sleeves. my question is this. I recently had all of the coolant ports on the exterior of the thermostat housing and the crossover pipe welded shut. when I went to fire the new build up for the first time and bleed the cooling system, I could not for the life of me get it to bleed. it was behaving like the thermostat was stuck shut. cold lower hose, hot upper hose, engine temps were 200 degrees. it has a Mishimoto 156 degree thermostat in it which was working fine previously. upon taking the thermostat out of the car and putting it in a pot of water on the stove, it opened up just fine before the water boiled like its supposed to. is the fact that I have all those ports blocked causing an issue with coolant not being able to flow properly? if I run this setup do I need to also delete the thermostat to get some flow back? if anyone has some experience with this I would appreciate the input. I have also contemplated just drilling two small holes in the face of the thermostat to promote some water flow even with it closed. any input would be appreciated. Side note, this is a big turbo car. Primarily a race car but will see street miles which was the reason for having a thermostat in the first place.

 

If you run a thermostat, you MUST use the bypass hose ("U" shape hose from the thermostat housing up to the intake manifold/cylinder head). Otherwise, you will overheat. If you don't want to use the bypass hose, you will need to begin drilling small holes into the thermostat plate until you can control the temperature by controlling the fluid flow.