Hi all.
The correct orientation is with the spring and wax chamber towards the engine.

- If there is no perforations in its plate, when the thermostat is closed cold, there is no flow of coolant for its heat to reach the wax, plus the pump pushes against the spring aiding to stay closed.
Without perforations on the plate, does anything change if orientation is reversed, as
- The force from the pump to the spring can help coolant flow at higher RPM and the slight opening allows the coolant heat reach the wax chamber at the opposite side.

With perforations on the plate, some coolant exposes the wax chamber to flow allowing the wax chamber to act.
With perforations on the plate; the heat reaches the wax chamber any way it is installed, and
If reversed, the spring does not fight against the pump.

With perforations or not, would a reversed thermostat have less chance to get stuck closed as the pump is applying some force to the spring to help open ?

Critic - comments ¿?



Pros and cons on 4 conditions:
-No perforations correct install
-No perforations reversed install
-Yes perforations correct install
-Yes perforations reverse install.
Yes, for inline.

 

With no perforations installed with the wax towards the engine the thermostat will open I'll be at there as a delay because it takes a long time for the coolant to heat up by conduction to a temperature that will allow the wax to move. On a D2 you will typically see a 180 thermostat Spike to 200 to 220 before it opens. With no perforations and the element reversed it's would take much much longer for the wax to open and you probably would not like the result. Have never tried a thermostat reversed with perforations but I doubt it would make much difference. I cannot speak to normal thermostats but the high flow thermostat that we use in our kits is so wide open when it is fully open that there is a little if any resistance.

 

Also, the water pump does not generate much pressure, it mostly just moves fluid around. I doubt it would generate enough pressure to matter. What Extinct said is correct. Really there is no reason to buy an OEM thermostat when the inline mod is so easy and bullet proofs the cooling system. I like the idea of the copper overflow hose someone posted, next time mine fails, I am going with that.

 

I'll quote you for your answer: "The correct orientation is with the spring and wax chamber towards the engine."

 

Just don’t orient it like this:



Ask me how I know and I why I felt like an idiot of immeasurable proportions when I realized why it was getting hot…