Quote Originally Posted by GeeYou8 View Post
I thought that the thermostat controlled the hot water leaving the engine into the top of the radiator to be cooled then pumped from the bottom of the radiator through the block (pump assisted thermo syphon).
Yes, that's right. That's why I had to install the sensor behind the thermostat in the block. The way to do that is to use the pipe that comes out of behind the thermostat that leads the hose to the heater core/LPG converter. That's what I've done in above picture in post number 36. Until thermostat opens, there is no flow. So, the water in the engine block+cylinder head stays there without flowing into the radiator and circulating. Obviously if the radiator is not full, some water will flow into the radiator via the water pump action, but that would be minimal and can even help engine warm up bit quicker. This is how the "burping" works as well. As we pour water into the radiator it goes into the cylinder head, then into the engine block while air bubbles coming out of the radiator with the help of water pump speeding it up. Some air bubbles may get trapped at the coolant lines between thermostat and radiator. That's why it's important to "burp" the coolant system until the engine is warmed up enough to open up the thermostat, so the whole circulation cycle completes while pushing out any air bubbles.