if you are using coolant the race car guys can not use water based coolants so everybody uses Evans waterless coolant . This stuff is expensive, about $25 per gallon, but it’s amazing stuff it’s way better than water based coolant , does nt coorode and is a supplier coolant often curing over heating in race cars .
Hi Eccentric, I have just been reading #27 again, as I replied to Badhippie about filling from top or bottom, but may have confused others as I definitely woke in the night (for other reasons) and pondered what was really happening...? - So, take it that I am confused...?
In your thought experiment (My middle of the night insomnia hobby!) I reckon you have a drain on the outlet. In the model you have a tank - the engine, etc. - presumably with top and bottom connections, and a water pump to make it flow (Thermo-syphon needs a large head to work - Models do not have enough height to create a useful density related pressure difference to develop the flow required...).
Hence, with a "second tank" attached to your fish tank - probably closed, not open to atmosphere, and maybe below the fish tank, I guess you will simply fill from the top connection until all the air is expelled from the bottom (closed) tank through the top tank (as a vent) until the top tank fills to the required level?
Does that help resolve the confusion? (Or maybe I'm the only one who is confused?).
Can you post a phot of your model - and a cooling-circuit diagram perhaps?