Back on my original kick about transfering hot coolant from one block to the coolant system of a cold block..........

Wouldn't there need to be a valve to allow air to be released from the transfer hose from the supply side of the hot vehicle...............and one on the transfer hose returning cold coolant to hot block?   Otherwise would be allowing air to enter the coolant system?

ie.....hook hoses, start the flow........open the air lock on supply until water came out, then close it...........same on return line?? 

Further..........re the comments below about water pump not producing pressure........would there be enough "pressure" to move the liquid 20ft from hot to cold, and back again?

Thanks.