What is Purpose of Coolant Bypass

[71Demon340]

I was looking at my intake manifold and water pump and I am trying to figure out the purpose of the bypass. Seems worthless to me. What does it actually bypass being that it is below the thermostat. I see that the "race" water pumps don't have the outlet that goes to the bypass. Looks like you could block of the bypass and still be fine. Could it be the high point vent for the pump? Just curious.

 

[RedFish]

It allows the water to bypass the thermostat when it is closed. Without a bypass you could have a super size air pocket traped in the engine when filling the coolant system. Also relieves back pressure on the pump when the thermostat is closed.

 

[71Demon340]

It allows the water to bypass the thermostat when it is closed. Without a bypass you could have a super size air pocket traped in the engine when filling the coolant system. Also relieves back pressure on the pump when the thermostat is closed.

So that means that when the thermostat is closed, water leaves the intake through the bypass hose and enters the water pump and goes back through the block? Guess I was looking at flow direction wrong. Thanks for the clarification.