Well thats a relief... thanks Bill. Now I can discount the pump altogether at least.
Today I pulled out the thermostat and put it into 65 degree hot water and it opened just nicely, so I can also discount the thermostat. Next flushed the engine with plain water, and refilled it with plain water as well. No mater how slow I poured the water, and no matter how high or low I put the tail (to get level), I could not get more than 2-1/2 liters of water into the engine. I then ran it at 4000 rpm for 5 minutes to try and clear any air locks so I could get the 4 liters the specs say, and she reached 170-5 degrees, but the main thing to note is the air lock did not clear and the water level stayed the same.
Back to the drawing board. Waited for the engine to cool down, then disconnected the radiator hose and hooked up the garden hose and flushed the whole engine both ways and noticed no discolor in the water at all. It all looks good, so put it all back together but before I put the thermostat back I drilled a couple of 1/8" holes in it to hopefully help the coolant seep through better so I might refill the full 4 liters this time. Its too dark now to do anymore now so will finish tomorrow and test fly and see what happens.
I didn't see and steam vent from the head, but did see what might be the steam vent coming off the top of the water pump and going back to the radiator cap. See the pic below and some others as well just to give you an idea of my setup.
Mike
Cooling.JPG (You do not have access to download this file.)
Overflow.JPG (You do not have access to download this file.)
RadiatorCap.JPG (You do not have access to download this file.)
Thermostat.JPG (You do not have access to download this file.)
TwinRadiator.JPG (You do not have access to download this file.)
WaterPump.JPG (You do not have access to download this file.)
