Help with expansion tank

[87chevy.com]

Originally Posted by Joyridin

Many people have literally plugged off the heater hose fitting on the water pump with no ill effects. I have one of those loop hoses, but I probably should have plugged them also as my car has no heater.

I did not put a tee in front of the VA shut off valve and mine works fine.

the point of the cross over tube is so the return flow from water pump that would go to the heater, runs back to the thermostat side for proper thermostat operation. When you block off the heater circuit, it no longer gets the proper flow if any on the other side of the thermostat.

On my 5 series bmw LS1 swap, at a long stop light or going through a drive through, I could watch the aftermarket coolant temp gauge start to rise, when I turn on the heater (not even, it opens the water valve and lets coolant flow in the heater core. almost instantly, the coolant temp dropped. I could blip the throttle some and it would also cool it down... Since I havnt installed the cross over tube, I just leave 1 valve open so the flow is like factory.