Thermostat upgrade, 180* to 160*

NeQX

Founding Member
Sep 30, 2002
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Infront Of You, NY
Well...Noticed in NY 50* weather even in rain, my car was running at about 195* (with my 180* mr gasket t-stat), then when I would beat on it...it would go as hot as 210*! Don't know about you guys but that is pretty hot for me since I have aluminum heads. The car is also a daily driver. So today I flushed out my pep boys 3core radiator, put in a 160* mr gasket took it for a spin...def. feel a difference. Car was running at about 170-175* which is right under the 180* which is top mark on my auto-meter gauge. Even with me shifting at 6grand noticed that the highest temp went was about 190-195*, and I only saw that once all day out of the many beatings. I can say that at 175* car pulls alot better then it did at 195*. If any of you guys are running hot with your combo and 180* t-stat dont hesitate to go 160*. I can't speak for other peoples setups, im sure if you have a really good fan and expensive radiator that 180* will work good, or on a stock setup. I am running proform fan, basic waterpump, pep boys 3-core. Gotta get this car back to track. :banana:
 
No, not a good idea from what I read.
Normal operating temperature of the 302 is in the 210 degree range.
Any cooler, like the 190 degrees that you were experiencing, the car will continue, in some cases, to run closed loop, or cold mode. Which ends up dumping more gas in the motor and you get a rich condition.
Mileage will suffer, but since your just dragin' the car, it might not make a difference.
 
car is daily driver, I dont like to see 210* in bumper to bumper traffic..and when I sprayed n2o and beat on it went over 210* I am not trying to obtain a heart attack, 180* on temp gauge is fine by me, only time it will be colder then that would be in cold winter, and now its spring time :) car def feels faster at 180* then at 195*, that thermostat owns me.

Blackfox - You're running stock heads/cam?
 
i live in AZ for a bit and had a 195 t-stat and my car was always over heating, put in a 180 and it was fine. id think if u went to 160 ur car wouldnt be able to warm up enough and would run like crap. personaly id stay with the 180
 
LX302 said:
No, not a good idea from what I read.
Normal operating temperature of the 302 is in the 210 degree range.
Any cooler, like the 190 degrees that you were experiencing, the car will continue, in some cases, to run closed loop, or cold mode. Which ends up dumping more gas in the motor and you get a rich condition.
Mileage will suffer, but since your just dragin' the car, it might not make a difference.


100% wrong! going from open loop to closed loop is TIME based, not temperature. The 160* is going to be bad in the winter when its 20* out, his car will barely warm up, but since he has an elec fan, he can keep it off so car does warm up eventually. The 160* stat was just a bandaid fix IMO, as its obvious because his car will still get 'hot' when he beats on it. Im having a similar problem as him, but my problem is the radiator I believe.
 
what about timing, if you have it too far advanced it will run hotter. this was happening to mine last week. it would stay close to 225 so i backed the dizzy off about 1/2-1 inch and now it stays between 190 and 200 and i feel no difference at all in performance.
 
Grn92LX said:
100% wrong! going from open loop to closed loop is TIME based, not temperature. The 160* is going to be bad in the winter when its 20* out, his car will barely warm up, but since he has an elec fan, he can keep it off so car does warm up eventually. The 160* stat was just a bandaid fix IMO, as its obvious because his car will still get 'hot' when he beats on it. Im having a similar problem as him, but my problem is the radiator I believe.


Some interesting info I found in the tech manual. When coolant temp is 190F and lower the EEC signals the injectors on EFI engines to increase their pulse width to richen the Air/Fuel mixture. Typical EEC-IV enrichment schedule calls for 2% increase in pulse width for every 10F degrees below 190F. In street service below 3000 rpm, if the engine runs too cool the computer will compensate with an over rich mixture at part throttle, because it has been led to believe the engine is still in "cold start" mode. The control module's "normal operation" mode is activated at 178F. If the engine does not reach this temperature, degraded throttle response, poor fuel ecconomy, and undesireable increase in emissions will result.

My car was running warm also in the summer with 180 degree thermostat. Around 210 - 215F in traffic and about 187-195F on the highway with a copper/brass three core and permacool electric fan. I just ordered a 2-core Aluminum radiator and a Ramchargers dual fan to take care of that and will stick with the 180F thermostat.
 
NeQX - you may buy a little time with a colder t'stat; but if your temps are doing what you describe, you have a fundamental cooling problem which you really should look into - especially before the really warm summer temps arrive. Either not enough capacity or a malfunctioning radiator, or not moving enough cool air across the radiator. Putting a lower temp t'stat in when temps are running too high is treating the symptom, not the problem.
 
Grn92LX & NeQX Or Mike and Mike in the words of James, your cars are JUNKKKKKKKKKKKKKKKKKKK, lol boys. I think Michael Yount is on the right track there. I would read what he wrote. I have not had any over heating problems with my car. In such a long time, and I run all most the same setup as you guys. I just a sn95 fan and a rad from mustang magic ( don't know the brand) but it seems to work for me.
 
instead of debating engine coolant temperature on the internet you can just have a peek in your vehicle owner's manual. "It is acceptable under certain driving conditions for the needle to rise to the very top of the normal band" or some such thing as that. Only when temperature gets to 270 degrees (hey... maybe THAT's why they put the red mark there!) should you shut the engine off as soon as safely possible to let it cool and determine the cause of the cooling problem.

It's incredible how people assume that because the water is too hot for them, the engine must not like it either. :p