Coolant flow
Well I thought I would try to see things with my own eyes. I grabbed a new 180deg thermostat and a pan of water and heated things up. These are my observations on this ONE test on ONE thermostat. So in no way would I consider this conclusive.
1. heating water and holding the temp over time is challenging but necessary. Thermostats don't appear react quickly to changes in temperature.
2.suspend the thermostat sideways so you have easy access to measure the amount the valve is open. Drill bits will work for go nogo gauges.
3. The water will cook off as you test. Preheating make up water in the microwave helps prevent lowering the water temp if you have to add water.
4. Use two thermometers (Everyone is still going to claim they are wrong).
5. Have a clock, pencil and paper, camera, thermometers, go no go gauges and beverage of choice ready before you start the test.
My results were that the thermostat started to open about 180 deg and stay slightly open .010- .030" until heated to around 185 degrees when it opened to around 3/16". At around 190 deg. it was at a 1/4". 195deg. about .300" pretty close to fully open. Fully open seemed to be around 200 degrees.
This would be pretty close to what would be considersd a properly working thermostst according the info from the motor manual info provided by 12many and the Chrysler factory service manual info provided by Mattax. Also the info shared from Dicer.