thermostat ?

The Stock EEC like to see 190 degrees, however a lot of guys run a 180 degree thermo with no issues.

You want to get a HIGH flow thermostat that has the bleed holes in it, Mr.Gasket, Stewart Components carry them, $9-$14

johnnyboy1111 said:

What do you guys think is the best all around thermostat in temp, brand , etc ? I'm running the hottest I could find which I think was 195 ...I was told that was a good choice now I'm not that sure

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I would say Motorcraft is best (followed by Mr. Gasket)...I run 180 degree thermostat on my car...

I like the Mr. Gasket. Since the weather will be getting colder I'm going with the 180.

I agree with 5spdGT on the motorcraft 180* being one of the best i've used. Of the many i've tested, it gives the best middle ground of not too hot and not too cold. When I had it I seemed to run around 180*. Im gonna be putting that one back in soon.

The mr gasket 180* ran my car too cold at night when it was cool out and it ran too cold in the winter. On a cool fall night it would run 150-160*, which is too cool for me unless im at the track. I just put in a mr gasket 195* stat as im doing a personal test to see how gas mileage is effected with a cool running car as opposed to a warm running car. Car runs about 30-40* warmer (200*) now, we'll see how that effects gas mileage

I put a alum. rad in my car and now it runs like 140-160 all the time, beforemthe rad swap it ran like 190. My car has been have real bad issues lately. could that be the prob.?? What does the car act like if temp isn't right for the EEC??

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Go no less than 180...your mechanic appears to be pretty accurate...

raph130 said:

195 is CRAP. get a 180. or a 160 if you want maximum performance.

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You ever heard of open loop and closed loop...those become a factor when you select a thermo that low...

Best all-around performance occurs around the 190 temp range...

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Gas Mileage is a pretty accurate teller of how your car is "really" doing...

He wants the best all-around thermostat...so go no lower than 180 or 195 would be fine...I'm responding to this guys specific needs and not for those "beaters" out there...

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it can depend on one's climate and the condition of the cooling system - some guys run a 160 stat so that they keep it under 220* after 15 minutes of traffic. one should look for the temp THEY are gonna run at - not the temp of the stat.

that said, i would not run cooler than a 180 - i second Rick's excellent advice - the Mr G stats are top notch (what i run).

as for what you said about needing a perfect 12 volts - i would hope that you have more than that. if you have a stock alternator, you might not even have the 'perfect 12 volts'.

there is debate on the OL vs CL stuff. i personally think that once they are hot enough to light off (can be very quickly with HEGO's), they work (independant of the actual engine temp).

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9 out of 10 cases a 160 thermo is way to cold. It does not allow the water enough time in the rad to properly cool down before it goes back into the motor. A 160 degree thermo can make a bad cooling system look good.....

THe OL vs CL thing has always interested me since I know the EEC NEEDS to see 190 degrees for proper operation. I data logged many different things with a 195 and 180 using my Speedbrain (FULLY ADJUSTABLE EEC, LIKE A DFI) and did not find any major differences, however with the 160 I did.

raph130- Running without O2's and properly tuned, I have to raise the total BS FLAG on that. There is no way to take the O2's out of the loop with a stock EEC and not have any adverse effects. Your car may have run fine at WOT but on the street down low it had to run for $hit and didn't get any type of gas mileage.

Rick, thanks for the info. i obviously dont have the resources you do - i was goin off what i have read (I've read that ECT needs to see 178* to go CL, and also that once the O2's are hot enough to light off, engine temps dont matter - they trim fuel nonetheless - from a very knowledgable guy in here).
but now you have REAL data for us - good stuff!

it is interesting the differences in puters and all - 4th gen camaros routinely run 160 stats (from what i have read [take that for what it is worth]. they dont use ECT feedback to light off lambdas, hence why the 160 stats work).

interesting stuff - Rick, thanks for the data and your thoughts.

I did a dyno test a while back when I had the TFS combo. First test the car was around 200* and made 299hp/329tq, then I have it a 1/2 hour cool down with NO other changes and it made 304hp/339tq with better under the curve and a slightly richer a/f. IMO a car that runs around 180* is the best middle ground. You WILL go faster at the track with a cooler runing car.

The ideal situation for performance and efficiency is warmer coolant temps, and colder intake air temps. There shouldn't be noticeable differences between 180 and 192/5F t'stats - either should work fine.

You should have enough capacity in the radiator to allow any temp t'stat to function properly - 160/180/195 - it shouldn't make any difference. For a street car, you shouldn't run without a t'stat; and if you run a racer without one, be sure you put a flow limiter in place of the stat. If you have any kind of winter at all, most folks find the 160 simply too low.

The ecu goes into closed loop as soon as the O2 sensors are hot enough to allow it do so. That usually occurs within 2 minutes of startup even on cold winter days for unheated sensors; for heated sensors, it can happen in as little as 15 seconds. Coolant temps aren't considered in that decision. So a low coolant temp (160 t'stat) won't inhibit closed loop operation - it's a myth. Heated O2 sensors were developed to allow O2 feedback as quickly after start up as possible to further manage emissions output. If temps get too high, the ecu will exit closed loop, and inject more fuel (rich mixture) to try and cool things down.

All the stuff about HP differences - well, the dynos are neither accurate enough, or repeatable enough to believe the 3, 4 Hp or ft-lb differences some have measured after 'icing' or cooling down. I have no doubt those numbers showed up. I just don't think you can trust them.

On a street car if you run electric fans, it's the higher of your fan control temps or your t'stat temp that will set engine operating temp in traffic assuming the system has enough radiator/fan to reject the heat. You can put a 160 t'stat in, but if your fan is on-off with thermal switches at 195-180 - then that's where you'll operate. Cruise to enough speed so that the fan's aren't needed, and then your op temp is set by the t'stat.

I use a 180 t'stat , and have my fans set to control to 187F. I measured my t'stat and it doesn't open until about 182, doesn't fully open til 184/5. So check your stuff if you're trying to control to specific temps. Just because it says '180' doesn't mean it's actually operating at 180.

Oh - the stuff about the coolant not staying in the radiator long enough with a 160 t'stat. Think about it. If the coolant's not staying the radiator long enough, the implication is that you're gonna be running warmer. If you put a 160 in, and the car's running at 160, then the coolant is staying in the radiator long enough to reject enough heat to get it to 160. If you put a 160 in, and it can't get down to 160, then the radiator doesn't have enough capacity to cool it that low. Remember, the radiator becomes less efficient at removing heat the cooler the t'stat is. That's because efficiency is a function of the difference in temperature between the air moving across the rad, and the coolant temp in the rad. The lower the coolant temp for a given ambient temp, the less heat the rad can reject. Said another way, it takes even more radiator capacity to reject the same amount of heat the lower the t'stat temp is. Don't confuse 'heat' and 'temp' - two different things. Lastly, if you put a 160 t'stat in, and the car is running at 140, then your t'stat is malfunctioning and not closing all the way, or your gauge/sender is either inaccurate or the sender is mis-located.