What thermostat?

[MrSony]

I have a 160 in my car now that I bought in the middle of summer when I was breaking the engine in, and while at idle even at 20 degrees outside, it will burble happily at 190F. But even in warm weather as soon as I take off, the temp dips way down past 160, and lately stays at 130 due to the cold. Should I get a 180 thermostat, or higher? I have an aluminum spectra radiator, plastic end tanks. I know I need one, so I'll be picking one up reguardless.

 

[L67ss]

180. No reason to ever run a 160

 

[Texas82GP]

I would probably go with a 195 up there in Iowa. Your winters are pretty cold and you want the oil to get hot enough to burn off the water vapor.

 

[MrSony]

180. No reason to ever run a 160

Yeah. It being my first motor build I was deathly afraid of cooking it alive because we had a weird bout of really humid high 80 degree days in May. I've never gotten around to changing it.

 

[L67ss]

Ive found when running without one altogether it'll run a constant 160°

 

[pontiacgp]

Sounds like the 160° thermostat is stuck open, the engine gives off enough heat to heat the coolant to 160° in any temperature unless your in Siberia. I have a 180° thermostat in my GP and it stays at 180° no matter how cold the weather is and in the summer it never overheats. My Jeep has a 180° thermostat and that keeps the Jeep nice and warm in the winter and it warms up quickly. Like L67ss said no reason to ever run a 160° thermostat. Are you sure your temperature gauge is right?

 

[pontiacgp]

And I should have added running an engine too cool is bad for the engine and transmission. The transmission depends on the heat from the radiator to help maintain the proper operating temperature of the transmission fluid. Operating an engine too cool the engine oil does not get up to the proper temperature to properly lubricate the engine

 

[MrSony]

It seems like the gauge is right. It got upto 230 one time when the fan belt flew off and i could hear and see the 50% water and 50% 50/50 mix boiling in the overflow jug. It hangs at 190 when sitting idle, but when you start moving and getting airflow it dips to 160 and on below 45 days 130 on the gauge. I think I'm gonna get a 180. Middle of the road. They're cheap enough that if it doesn't perform to my expectations, buy another or exchange it if they let me.

 

[pontiacgp]

It seems like the gauge is right. It got upto 230 one time when the fan belt flew off and i could hear and see the 50% water and 50% 50/50 mix boiling in the overflow jug. It hangs at 190 when sitting idle, but when you start moving and getting airflow it dips to 160 and on below 45 days 130 on the gauge. I think I'm gonna get a 180. Middle of the road. They're cheap enough that if it doesn't perform to my expectations, buy another or exchange it if they let me.

50/50 water and antifreeze at 15 psi the boiling point is 267°. Where do you have the temperature sender?

 

[MrSony]

50/50 water and antifreeze at 15 psi the boiling point is 267°. Where do you have the temperature sender?

It's in the intake. And at the time, the mixture in the rad was 50% tap water, and then 50% premixed 50/50 coolant and water. A few days prior I pitched a fan belt (first time) due to a pulley misalignment and it knocked the lower rad hose off. Was far from home and didn't have any cash on my to buy coolant. Just borrowed a garden hose filled it up and went on my way. I'm fairly confident they're correct.