Experimenting with thermostats


We’re saying the same thing.


I’m saying it doesn’t matter if there is a T-stat or not, if you only assume operating temperature. I think you made reference that when open, it blocks flow back to the pump and diverts only to the radiator. Nothing physically gets blocked is my point.


Ah so. I see what you mean. Then we don’t agree.

  1. I looked over the tstat really closely when I drew the conclusion that an open tstat routes water from the head to the radiator, and blocks the path from head to water pump. If you spend 10min with the tstat housing in your hands, looking carefully at the water routing caused by a cold tstat vs. a hot tstat, a person is gonna be forced to draw the same conclusion.

  2. If I understand what you’re saying correctly, it wouldn’t work. If water from the head is allowed to go right back to the pump, that’s where it’s going to go. This is because the pump intake is the lowest pressure in the system. The idea that water can go from the head to any place it wants because the tstat housing is full, is wrong. Because if that was the case, the water wouldn’t go to the rad at all.

Common sense tells us that when the tstat is hot, the coolant system would be designed to ensure that all water goes thru the rad. And the only way to make that work, is to ensure that the route back to the pump is thru the rad.


OK, I think I see what you mean,

For some reason, I was looking at the secondary piece of the t-stat that mates to the internal machined flat on the housing casting. I thought that that moved open, If that were true there is nothing diverting coolant anywhere when open.

Upon further review, I believe that just has a spring to take up tolerances and is closed at all times.

I think the confusion came from the statement that when the T-stat opens it closes another path. Technically this path is always blocked no matter closed or open, and is only unblocked if the t-stat is removed - which to your point then skips the radiator.