this is the first engine i have had with aluminum heads.
the papers that came with the engine said not to let the engine get to 280*.
the compression ratio is 9:9:1, with pro comp heads. it has a 3 core champion radiator with 2 fans, with a 160* stat.
open road for 18 miles my engine will run about 170-180*. when i enter town the speed limit is 25 mph and my temp goes to 215-220*

i guess what i am asking what tempetures are you running when the ambient tempeture is 80*. there is no way i am going to run it even close to 280*

 

I'd get rid of the 160 stat and put in a 180. That will give the coolant more quality "chill time" to spend in the radiator.
On the open road, mine hangs at 180, and in traffic it can get up to 190 or a tad above. That's with a single electric fan.
I don't think I've ever seen my engine get to 200.

 

the engine builder recomended the 160* stat????????????

 

I wonder why. In a perfect world, if you could drop the temp of the coolant in the radiator rapidly, the engine would never get past 160, which is way too cold to be at. But this isn't a perfect world, which is why you need to experiment. Running a lower rated stat does not necessarily mean the engine will run cooler. You need to find a happy balance in the cooling system, and experimenting with a different stat is a good place to start. Your engine shouldn't be getting up to 210 on an 80 degree day.

 

you say more chill time, but once the thermostat is open it is open.
you have a 180 i have a 160 we let them idle , my stat will open first then yours. they both have the same opening to alow the same amount of flow
maybe i am missing your point

 

Yeah, I think you are missing my point. Try not to think about when the stat is open, but if and when it's closed. With a 160 stat, there's no way in heck you're going to be able to hold an engine at 160 degrees. That means yours is running wide open after the first opening of the stat. On mine with the 180, I've got another 20 degrees to go before the stat opens. But, you say, what difference does that make if both stats are staying open? None, but that's assuming the stat is staying open due to the radiator and fan not being able to keep up with getting things cooled back down. Provided your radiator can cool it down very well, your stat could be able to operate with a designed closed-open-closed-open cycle. This way, the coolant will stay in the radiator longer (more chill time) and get a chance to cool better.

 

WELL, i think i fixed the problem. i removed those @#^*#% electric fans, added a flex lite fan and shroud.
i let the engine idle till the stat opened, drove it 10 miles, put it in the garage and let it idle for 15 minutes. the tempeture only went to 195. i'll know more this week end when i take it in traffic