Thermostat

[AH64ID]

I think the bypass is rather important, especially when you consider that these thermostats spend more time closed than open unless you tow all the time. 

 

Or is it a completatly different setup on a 12V?

 

 

Edited April 23, 2018 by AH64ID

[ofelas]

I believe we are saying the same thing in a slightly different way.

 

It's import to bypass during warmup - the NAPA/Mopar/Stant stat's lack of a bypass disc doesn't prevent the bypass flow - when the stat is closed, the bypass is open, and fulfills it's primary function of circulating a trickle coolant through the head. The engineers should have made the rear freeze plug divert as well, but that's easily fixed. On my setup, I divert the stagnant #5 & #6 coolant to my heater core inlet via a Keating Machine tapped freeze plug insert.

 

When towing, and the stat opens to regulate temperature, the bypass closes - this doesn't really cut down flow through the upper rad hose; I've heat gunned the difference back to back on the same day before & after the stats opened. The tiny bypass doesn't really have a chance at affecting a fully open stat's monster flow that these very stout water pumps facilitate.

 

I'm not concerned about the bypass function, as its only there to

close & prevent flow through the bypass passage when the thermostat is open & provide 100% flow through the rad hoses.

 

The bypass hole is too small to make a difference to cooling flow whether closed or open; its primary function is to ensure a bit of coolant circulation when the thermostat is closed, to help avoid hot spots while warming up.