As I'm getting to the point where the motor fits the car now and need to figure out the little things like coolant and oil routings. How does the thermostat work. I see the port with the metal nipple on the housing gets close off when the engine gets up to temp, but it almost looks to have its own wax valve on there to move independent of the main thermostat body. I've learned in dealing the the stock mazda B series motor that the trick to engine cooling is to have all the water go through the radiator and to shutoff the heater core bypass unless the heatercore is cold. With that motor I used a thermostat that was open cold and closed hot, so it would open when the engine was cold and also if I was running the heat to defog the windows when racing in the rain but would be closed when the engine was up to temp. If thats the case with the stock thermostat setup on the mzr, err I mean duratec, then I'm golden and I can plug the small nipple on the plastic cap or buy a waterneck with only 1 port. If not then I'm going to also end up with some bastardized T off the ford ranger water outlet to supply water to both that metal nipple as a bypass and the heater core. Forgive me if its been answered before, google didnt really provide a solid answer on if the heater actually worked once plumbed the way I described, and I couldnt tell for sure after boiling mine and then sticking only some of it in cold water.

For reference, the ford ranger water outlet is what cosworth buys and cuts down in order to make their shorty with bypass water outlet.