I have always used the 180 temp here in this area of the country..just flush out the system the best you can before you put it in..and be careful taking out the thermostat bolts..they can be a bit testy if they haven't been out before..

Rich

I'd also go 180*. If your new t-stat has a small hole with a chunk of metal(restrictor) in it, take some side cutters, or something like that, to cut the chunk out, leaving just the small hole. The hole will allow you to fill the system much easier, plus the whole purpose of it is to allow a small amount of coolant circulation before the t-stat actually opens....this is a good thing!
If your t-stat does NOT have this hole, with the restrictor(chunk) in it, take a 1/8" drill bit, and drill a hole in the flat area of the t-stat, between the center, and the outer edge...this will accomplish the same thing.



Adams' Apple2011-04-11 20:16:18

  That's a NEW concept for me Joel!  Have not heard of that before. I am changing mine to 195, from 160.  Think it will run better, burn ALL the fuel, not push some of it through the system. I will check for the HOLE and plan accordingly.  THANKS   The new loomeum radiator should take care of MOST of the heat kept at bay.

Mark it is used on most all new cars for some time now..it is a great way to avoid the almighty air pocket when you D and F the coolant..some even have a little pressed on check valve to keep the coolant or air from going back into the engine..not really needed on these cars since the thermostat points up.

Rich

The temp rating of the t-stat is only for the opening temp, meaning, that's when the t-stat opens. It will not actually control how hot the engine runs...only the time it takes to get there.

I would suggest buying a thermostat that has a fail-safe design...that if it goes bad, it will do so in the open position.  That will keep the engine from overheating in that event.  They're a bit more expensive but worth it.

What temp does vette run at now. When i drove my car daily in the summer i ran the 160 and in fall i put the 190 back in. Well what ever temp you go with I would suggest buying a thermostat that has a fail-safe design...

Alright guys I'll bite..what brand of thermostat has a fail safe mode? Never seen or heard of one..

Ok I googled it quick ..doesn't look good..most of the posts about them look bad..like they stick shut..might not be a done design..neat concept though..I use the balanced ones..open and close when they are supposed to..the studies I found online show our old cars make more power with the 160' thermostat versus the 180.. but it wears the engine internals faster..not sure how but that's what I found..I think mine was a mr. Gasket brand..180'..

Richyostusota2011-04-13 08:11:37

Doesn't really matter what the temp rating is...the engine is going to run hotter than that anyway. Otherwise, the thing would never open, or it would just sit there and go open/closed/open/closed/open/closed.
As I've said(and others too), the rating on the stat is OPENING temp. A 160* stat is gonna be open at 160*...a 180 will be open at 180...period. Having a 160 degree stat doesn't mean your engine will only run 160 degrees all the time...that's physically(and thermally) impossible. It just means the stat will open 20 degrees cooler than a 180 stat....that's it. The engine is still gonna continue to create heat. It's the job of the cooling system to control that heat...NOT the thermostat.
Around here, an engine with a functioning cooling system, with a 180 degree stat, will average around 200-210 degrees coolant temps, depending on the cooling system design. Installing a 160* stat will NOT lower that engine operating temp....but it will start coolant flowing thru the radiator sooner.