quote:Originally posted by ANGELO B:
... What is the reason for the line to the pump inlet?
Angelo
It converts an expansion tank into a header tank. It allows coolant entering the tank from the vents to recycle into the cooling system, while air remains trapped in the top of the tank. It establishes the tanks pressure as the same as the pressure at the coolant pump suction, which is the lowest pressure zone in the cooling system.
quote:Originally posted by ANGELO B:
... Would the venting issue be resolved by moving your air bleed from swirl tank to the bottom of the overflow tank, eliminating the line to the pump?
Angelo
No
quote:Originally posted by ANGELO B:
... The system would still vent and with the swirl vent line in the bottom of tthe overflow tank, as the system cooled it would draw liquid back into the system. ...
Angelo
It would only vent until the tank filled up or the pressure in the tank equaled the pressure of the vents, then coolant would stop flowing.
The venting system works as drawn ... this coolant system design is not mine, it has been used by race car constructors for decades (since at least the 1960s if not before), check out Carrol Smith's books. Half the cars on the road today have header tanks as shown in the diagram. Venting the coolant system to a header tank is what allows modern cars to use such small radiators. The Edelbrock coolant pump has an extra port on the right hand side which connects to the pump's suction, this extra port makes the connection to the header tank very easy to accomplish.
-G