Please help settle a bet/discussion. A coworker and fellow musclecar fan from Ohio says there's no need to run a thermostat in climates where it doesn't freeze. Even goes on to say that the car runs better and with a more consistant temp w/o it. What's the consensus here?

I call BS, the t-stat has nothing to do with the outside temp, it is there to get the engine up to operating temp and keep it there regardless of the temp outside the car. His statement about having a constant temp without a t-stat is utter nonsense, the t-stat is there to keep the temp constant, without it the temp could vary widely and some engines will overheat without a t-stat. In order for the engine to have a long service life the oil, coolant and metals all need to be within a desired operating range, if the temp is too low or too high for extended periods of time the engine internals can and will suffer damge and/or excessive wear. Also fuel mileage will suffer and performance will be lower (a cold engine tends to run dirtier and an excessively hot engine produces more NOx and can have excessive detonation).

ditto to that. t stat is to keep the car at an operating temp range.

Joe is right on, the stat is there to get the engine up to temp quickly. Without it the coolant is flowing as soon as the engine turns over and takes longer to warm up. Once the engine is up to temp, if the rest of teh cooling system is doing it's job and starts to cause the temp to drop the stat closes and alows the temp to come back up.

I agree with the above posts. You need some sort of restriction to keep water temps stable. Even race cars that don;t run a T-stat use restrictors to keep engine temps in a desired range. I did a little experimenting with that and found that the easiest and best way is to run a good quality t-stat and let it do it's job.

Without a t-stat or restrictor the engine temps will vary greatly.

Thanks for the replies. It was what I thought, and what I've learned from this board. This issue came up because I drove my Camaro to work today with the new engine installed. Everything thing is new (new 4-core radiator, new Victor series water pump, new March serpentine-style high flow pulleys, AND a new Hi flow/Balanced HP t-stat)

During my 50 minute commute, the temp would swing between 180* and almost 205*. I was afraid of cooking my brand new engine!

I'm going to try installing the "regular" 180* t-stat from my old engine before I drive it again.

It freezes in Ohio . . .

Definately run a thermostat. There's no need not to because a high flow stat flows enough to keep pretty much anything cool.

During my 50 minute commute, the temp would swing between 180* and almost 205*. I was afraid of cooking my brand new engine!

I'm going to try installing the "regular" 180* t-stat from my old engine before I drive it again. I wouldn't, at least just yet... 205 isn't going to hurt your engine. I understand not wanting it above 180-190 but before swapping stats I'd verify the temp reading with an IR heat gun. When does it hit 205 and when is it running 180? At speed or sitting? Makes a big diff in what direction you go to stabilize things. In the meantime you are not getting hot enough to damage anything.

What he said.... if the motor runs at a higher temp than the thermostat, that means the cooling system is unable to transfer all the heat.

If it heats up at low speed/rpm, stop lights and such, check your fan and shroud.
If it heats up at highway speeds (like mine) you don't have enough cooling capacity.

I use a hi-flow stat and haven't had any problems with it.. :thumbsup:

Faster68:

In addition to all the good reasons listed, there is another very important one for using a T-stat. The cylinder bore ware increases tremendously when the block temperature drops below 180* there is evidence that shows cylinder ware ramps up off the chart. So keeping the block temp steady and above 180 will increase the life of the motor. Runnin' to cold can be almost as bad as runnin' to hot

I also vote to use it. I have a 195 in mine and it hovers between 180 and 205 most of the time. The engine isn't quite broke in yet but seems to stay close to the 195 except in traffic.

your new motor is it bored at, all if it is its going to run a little hot my dad has a brand new chevy truck with a 5.3L V8 it runs 210 all day long. some motors just run hot.

The "balance" thermostats are far superior to ANY regular one. Leave it be. My bet is the gauges are off somewhat. Where is your temperature sensor....block, intake, head? Head readings usually will indicated higher due to exhaust manifold/header heat taint. Intake positions are the most accurate.

Djd is right on...205 is no biggy. I would worry when it starts to get 230 and unstable actually.

http://performanceunlimited.com/illustrations/thermostats.html

That's what I was hoping - that the balanced HP t-stat would be better overall. I haven't changed it.

I drove it this morning. I could tell that it opened inside of 7 minutes of starting at 185*. Once opened, the temp dropped to 170*. Over the next 5 minutes of slow driving, it crept up to 200* before settling in at 185*.

I'm just not used to such wide temperature swings like that. I had my 327 setup to the point where it would only gradually rise, and only touch 200* on the hottest of days.

It's the same mech temp gauge as the old engine, the temp probe is in the (same Air Gap) intake manifold, and the water pump and radiator are new, better pieces.

During the afternoon drive around town, I was dogging the snot out of it, and it held pretty steady at 184*. I can live with that, it's just the "headin' to 200*" on startup that scares me.