160 or 187 degree thermostat a new twist, old test and a SURPRISE!!!

[98 tigershark]

Last year I installed a 160 degree thermostat because most tuners had a pretty good argument and experience with hundreds of installs and tunes.
Ever since then my car would be seasonal. By that I mean in the spring it would not warm up well and in the summer it would run hotter by quite a bit. The new 160 degree thermostat was replaced with a new 160 degree stat as I thought the new one may be bad. Wrong it worked great. The test I used, was what I use to do in the stone ages. I put the 160 degree stat in a pan of water on a stove and around 175-178 degrees it opened great I thought. But what about closing as that is just as important? It closed around 190 degrees but when the cooled water from my car radiator was used the thermostat stayed open as it was to hot after about 6 cycles and the 160 degrees was to low a temp for my cooling system and the 160 degree stat and cooler fan settings would not allow the water from the radiator to close the thermostat and my car would over heat under load and or traffic in the summer. So I did the same experiment with the 187 degree stat and bingo, the stat always closed after unlimited cycles and now my car does not over heat under load or in traffic as it closes at a higher temp allowing the fans or air to cool the water enough to close the 187 degree stat which is also allot closer to my oil temp. So in my case no mater how the fans are set up the 160 degree stat does not close in the summer with a few cycles in traffic or load on a hot day and caused the car to overheat. The 187 degree stock stat closes on every cycle no matter the load or traffic, which allows the fans and air to cool the radiator water enough to cool it to under 187 degrees and close but not the 160 degree stat which became open and stayed open after load or slow traffic on a hot day.
The 187 degree thermostat also closed in the stove pan test. So do you think it is easier to cool 205 degree radiator water/oil/tranny fluid to under 187 degrees and close the stat or the 160 degree stat that opens on a hot day under load and or in heavy traffic? My oil temp, motor, tranny is always higher than the 160 degree state by allot and I think the engine/oil/tranny fluid temp plays a big factor. I also seem to get better fuel milage now. I am not saying the guys that use the 160 degree stats are wrong but the facts and the pan on the stove test say allot.

[gmh308]

Last year I installed a 160 degree thermostat because most tuners had a pretty good argument and experience with hundreds of installs and tunes.
Ever since then my car would be seasonal. By that I mean in the spring it would not warm up well and in the summer it would run hotter by quite a bit. The new 160 degree thermostat was replaced with a new 160 degree stat as I thought the new one may be bad. Wrong it worked great. The test I used, was what I use to do in the stone ages. I put the 160 degree stat in a pan of water on a stove and around 175-178 degrees it opened great I thought. But what about closing as that is just as important? It closed around 190 degrees but when the cooled water from my car radiator was used the thermostat stayed open as it was to hot after about 6 cycles and the 160 degrees was to low a temp for my cooling system and the 160 degree stat and cooler fan settings would not allow the water from the radiator to close the thermostat and my car would over heat under load and or traffic in the summer. So I did the same experiment with the 187 degree stat and bingo, the stat always closed after unlimited cycles and now my car does not over heat under load or in traffic as it closes at a higher temp allowing the fans or air to cool the water enough to close the 187 degree stat which is also allot closer to my oil temp. So in my case no mater how the fans are set up the 160 degree stat does not close in the summer with a few cycles in traffic or load on a hot day and caused the car to overheat. The 187 degree stock stat closes on every cycle no matter the load or traffic, which allows the fans and air to cool the radiator water enough to cool it to under 187 degrees and close but not the 160 degree stat which became open and stayed open after load or slow traffic on a hot day.
The 187 degree thermostat also closed in the stove pan test. So do you think it is easier to cool 205 degree radiator water/oil/tranny fluid to under 187 degrees and close the stat or the 160 degree stat that opens on a hot day under load and or in heavy traffic? My oil temp, motor, tranny is always higher than the 160 degree state by allot and I think the engine/oil/tranny fluid temp plays a big factor. I also seem to get better fuel milage now. I am not saying the guys that use the 160 degree stats are wrong but the facts and the pan on the stove test say allot.

Which is why I like stock thermostats .

[macca_779]

Interesting testing. But I must say after having a 160F in my engine for 2 years now in multiple climates. It still works a treat. The coolest the engine gets at highway speeds where the fans have no control and in cold climates (<10c) the engine sits around 78c. In the hottest climates where I live I often experience >45c and the highest I've ever seen ECT get to is 85c.

[98 tigershark]

I am sure it works fine in your car but it is a pretty simple physics problem.
The combined personality of my motor IE (625hp, 609 trq) the lower rated temp 160 degree thermostat would not close on a hot day after around 6 cycles or so. I went thru 2 stats also. I know it works fine for many tuners but not my car and the guys at GM performance said they do use the stock 187 stat for that reason also. As I said there are many guys that use them (the 160's) and they are very good at what they do. The radiator water would not close the 160 degree stat in a pan of water on the old 160 or the new 160, but did on the 187 every time and now my car does not overheat, so I am glad yours works and mine works. I would have liked to run my motor at a cooler temp also but no luck for me.
98 tigershark