160 Thermostat - Good or Bad?

[William M.]

1973 Big Block with AC.
What are the pluses and minuses of using a 160 degree thermostat?
Active debate is raging on the Corvette Forum regarding the effect on engine longevity. I trust you guys more. I'm listening ...

[Joe L.]

Re: 160 Thermostat - Good or Bad?

1973 Big Block with AC.
What are the pluses and minuses of using a 160 degree thermostat?
Active debate is raging on the Corvette Forum regarding the effect on engine longevity. I trust you guys more. I'm listening ...

William-----


First, you must keep in mind that the thermostat only controls the LOWEST temperature that the engine will operate at (after warm-up, of course). It does NOT control the maximum temperature that the engine will operate at.

The cooling systems of Corvettes, especially big blocks, are generally not capable of maintaining a 160 degree temperature except in very low ambient temperature conditions or during prolonged downhill grades with the throttle essentially closed and the car zipping along at 60+ MPH. So, using a 160 degree thermostat allows a greater SWING in operating temperatures than is desirable---going from 160 degrees under a few operating conditions all the way up to 220 or 230 under other conditions. This is not a good thing.

Beyond that, engines operate more efficiently at temperatures considerably above 160 degrees. So, rather than being beneficial, I consider 160 degrees to be detrimental. It was OK back in the 50's, but not for 60's and later cars.

My recommendation: use a 180 degree thermostat for 1963-72 Corvette applications.

[Clem Z.]

Re: 160 Thermostat - Good or Bad?

what is even more important what temp does the oil reach as too low a oil temp causes the moisture not to be boiled out of the oil. on the dyno i have seen 18 HP difference with a 20 degree increase in oil temp

[Dennis A.]

Re: 160 Thermostat - Good or Bad?

Does drilling a small hole in the Thermostat a good thing to do?

[Jim T.]

Re: 160 Thermostat - Good or Bad?

Interesting HP increase with hotter oil. Oil temp with my 96 LT4 on the interstate runs about 204 and has a 195 thermostat.

[Dan H.]

Re: 160 Thermostat - Good or Bad?

On the SHP and FI cars, what cooling effect does the thermostat bypass have when cold and hot?
Dan

[Joe C.]

Re: 160 Thermostat - Good or Bad?

1973 Big Block with AC.
What are the pluses and minuses of using a 160 degree thermostat?
Active debate is raging on the Corvette Forum regarding the effect on engine longevity. I trust you guys more. I'm listening ...

The trick is to keep the oil hot, the coolant about 40 degrees cooler, and the intake manifold cooler still.

[Joe C.]

Re: 160 Thermostat - Good or Bad?

On the SHP and FI cars, what cooling effect does the thermostat bypass have when cold and hot?
Dan

Dan,

I do not think that BBC water pumps have an internal bypass. All SBC, SHP engines have both external and internal bypass. SBC "water" pumps without an external bypass only have a much smaller internal bypass. BBC water pumps without external bypass have no bypass.
One purpose of the pump bypass, is to promote a small amount of circulation before the thermostat opens, to ensure even heating on warmup. If your car does not have C60, then the water is always circulating thru the heater core, which provides the same function.

[Martin M.]

Re: 160 Thermostat - Good or Bad?

Interesting HP increase with hotter oil. Oil temp with my 96 LT4 on the interstate runs about 204 and has a 195 thermostat.

Is this with A/C on, or off?

Marty

[Clem Z.]

Re: 160 Thermostat - Good or Bad?

normally the oil temp is 10 to 30 degrees hotter that the water

[Loren L.]

Re: 160 Thermostat - Good or Bad?

Depends on your point of view - In Arizona in summer the point is to let the water/coolant flow as soon as possible; achieving proper oil temperature will NOT be a problem.

[Clem Z.]

Re: 160 Thermostat - Good or Bad?

Depends on your point of view - In Arizona in summer the point is to let the water/coolant flow as soon as possible; achieving proper oil temperature will NOT be a problem.

yes but it is DRY heat correct ??

[John N.]

Re: 160 Thermostat - Good or Bad?

what is even more important what temp does the oil reach as too low a oil temp causes the moisture not to be boiled out of the oil. on the dyno i have seen 18 HP difference with a 20 degree increase in oil temp

Clem
What viscosity oil were you using on that dyno test?
Regards

[Dale S.]

Re: 160 Thermostat - Good or Bad?

I've never seen a engine sweat in Arizona. I hope this goes over better than my tire rental joke. Dale

[Clem Z.]

Re: 160 Thermostat - Good or Bad?

Clem
What viscosity oil were you using on that dyno test?
Regards

10W-30 mobil 1 temp went from 180 to 200. to get accurate repeatable HP reading on a dyno the oil temp should be within 2 degrees and the fuel temp 5 degrees. the oil pump kills HP that is why NASCAR engines use 0W-10 for qualifying with the oil pressure turned down on the dry sump pumps and heated oil in the dry sump tank. some times they go too far and screw up the engine