Which thermostat to use ???

[Brooks James]

70 Dart, mild plus street 360 magnum with a shot of gas 100 hp and a timing retard MSD 8680 module and nitrous controller
No ac, no heater
Aluminum radiator, (which satisfactorily cooled a 350 superchargedchevy) twin electric fans with electrical thermostat which I was thinking
Of setting off at 180 and on at 165
Hi vol water pump
Oh mostly street use
Shroud if necessary
I’m am unsure as to which thermostat
Is the degrees that important for emissions ( I know that I would be emissions exempt but want to do my part if I can) or does it have any thing to do with engine combustion efficiency
Or even factors not mentioned
Just to be clear I am talking about both the engine AND fan thermostat
I am extremely grateful to be an FABO
Member there is an plethora of knowledge and of experience literally I would guess thousands of years worth

 

[toolmanmike]

Don't use the cool one use the 180°. The engine will run better/make more power if it runs around 200°

 

[Darter6]

Is the degrees that important for emissions ( I know that I would be emissions exempt but want to do my part if I can) or does it have any thing to do with engine combustion

Yes,^^^^

I see you are in Florida, The theory is the hotter the engine runs the better it is for less emissions.Some new cars run as hot as 210* that was crazy hot back in the 60's.Normal was a 160* then. Remember the thermostat "Begins" to open at said degrees and may be several degrees more till it fully opens.So sizes for our old engines range from a norm of 160* 180* and 195*.
I would opt for a 180* and see how it works in the hot humid Florida summer.
If your fan control is adjustable set it so the fan will come on at 185-190* so the thermostat stays open while operating and maybe set the fan to turn off at 175*. It may be some thing you will need to play with.

 

[yellow rose]

70 Dart, mild plus street 360 magnum with a shot of gas 100 hp and a timing retard MSD 8680 module and nitrous controller
No ac, no heater
Aluminum radiator, (which satisfactorily cooled a 350 superchargedchevy) twin electric fans with electrical thermostat which I was thinking
Of setting off at 180 and on at 165
Hi vol water pump
Oh mostly street use
Shroud if necessary
I’m am unsure as to which thermostat
Is the degrees that important for emissions ( I know that I would be emissions exempt but want to do my part if I can) or does it have any thing to do with engine combustion efficiency
Or even factors not mentioned
Just to be clear I am talking about both the engine AND fan thermostat
I am extremely grateful to be an FABO
Member there is an plethora of knowledge and of experience literally I would guess thousands of years worth

Do you want to make power and reduce detonation or are you worried tail pipe emissions will kill the earth and all that populate it?

If the former, run the coldest thermostat you can and still run the heater, unless you’ll never need the heater or the defrost feature. You will make more horsepower and reduce detonation with cooler engine temps.

If the latter, runs 205 degree thermostat if you can find one.

 

[ChargedDart75]

Don't use the cool one use the 180°. The engine will run better/make more power if it runs around 200°

There was an engine test with Engine Masters that shows a warmer water temp made less power than a colder one. They saw that a hotter oil temp and a colder water temp made the most power than both being hot.

 

[toolmanmike]

I think it's more about thermal expansion if you will. Nobody starts their race engine and makes a pass without a warm up.

 

[Brooks James]

Do you want to make power and reduce detonation or are you worried tail pipe emissions will kill the earth and all that populate


If the former, run the coldest thermostat you can and still run the heater, unless you’ll never need the heater or the defrost feature. You will make more horsepower and reduce detonation with cooler engine temps.

If the latter, runs 205 degree thermostat if you can find one.

I’d like to have my cake and eat it too
Lower emissions more power

 

[383Scampman]

I’d like to have my cake and eat it too
Lower emissions more power

You can't have it all but you can get close . 318/360 Magnums are designed to run a hotter temps (195-210). 318/360 LA engines were designed to run (165-190) . EVERY engine DIFFERENT . I suggest you get a 160 , a 180 and a 185 * stat with abunch of gaskets and experiment to see which one the motor likes . AS far as emissions is concerned I suggest you purchase high flow cats and add them to your exhaust system . Stay safe .

 

[Darter6]

experiment to see which one the motor likes

Just like humans,we all are different and have different likes.What works for me,may not work for you.

 

[yellow rose]

I think it's more about thermal expansion if you will. Nobody starts their race engine and makes a pass without a warm up.

Absolutely not true. When the situation allows (this is a FACT not a guess) cars that can run with cold coolant and keep it cold do it.

For example, Pro Stock. They leave with a MAX coolant temp of 100 degrees F and want to be not warmer than 130 in the lights. Most can keep it to 120.

If you are talking about an endurance race where they allow barely enough fuel to power a weed eater for 400 miles, and you don’t have a chance in HELL of keeping the coolant temps cold like that, they go the other way.

They get the coolant temps up to 240 or a bit more if they can and keep it there. If they could run 280 and control the temp they would, because the advantage of keeping the air out PF the radiator for an aerodynamic advantage is a better trade off than a big open frontal area to get enough air to drop the temp.

High coolant temps mean less power every time. Higher coolant temps decrease detonation resistance and IIRC for every 10 degrees of coolant temp increase it’s a out a 2 point drop in octane rating...or close to that.

 

[yellow rose]

You can't have it all but you can get close . 318/360 Magnums are designed to run a hotter temps (195-210). 318/360 LA engines were designed to run (165-190) . EVERY engine DIFFERENT . I suggest you get a 160 , a 180 and a 185 * stat with abunch of gaskets and experiment to see which one the motor likes . AS far as emissions is concerned I suggest you purchase high flow cats and add them to your exhaust system . Stay safe .

Engines are NOT different. The end game may be different, but thermodynamics and power production don’t care what name is on the valve cover or what generation the engine is.

The magnum engines were forced into higher coolant temps. It’s not for power.

 

[yellow rose]

I’d like to have my cake and eat it too
Lower emissions more power

You realize that’s just not how it works. You will not increase coolant temp and make more power. You will also be less likely to control detonation unless you are willing to give up power there.

So tell me...how much more emissions will lower coolant temps cause, and which one of the gasses will causes the most environmental damage?

I’d like to see the numbers. Don’t forget, the “a modern” junk has catalytic converters to clean up tail pipe emissions. So account for that in your answer.