With regard to this project, I'm nearing completion. I still need to plumb in the water-cooling portion of the turbocharger. The two basic suggestions have been to take coolant from either the heater circuit or expansion tank circuit and return it into heater return. Taking coolant from the expansion tank would always be cold coolant and so would extend warmup times as opposed to the heater circuit. With the heater circuit I would be running hot coolant through the turbo and returning it to the engine uncooled. To me that's uncool (pardon the pun). Sooo, that brings me to asking a coupla questions. On the top of the thermostat housing it seems that there is a temperature sensor and also just a simple bolt head. What's going on with the bolt head? Could I plumb the return in there instead? If I could, then it would seem that I would be returning the hot coolant pre-thermostat and so it would be added to the mix and either be cooled by the radiator if the thermostat was open or add to the warm-up time by running back down the bypass. Sounds good to me. The other question then becomes where to draw coolant from. What is the small metal line that runs from the waterpump up to the head? Is it under waterpump pressure? Also, under the exhaust manifold there appears to be a large allen head plug. I assume that is the plug that JimSmith referred to. Can that plug merely be tapped for NPT in the center of the plug? If so, then I believe that would be the easiest route. I assume the plug merely unscrews from the block. Thoughts and ideas are welcome.

Andrew