Radiator cooling

[jww426]

Hello!

On both my chargers, a 68RT 440, and my 66 Hemi,
both cars run cool in the colder weather at about 160 degrees.
Is this a thermostat issue or is it just the way they were back then?

Many thanks
John

[Bronzedodge]

Sounds like they both have 160 deg thermostats.  If you get a good bit of driving in during the colder months, a 180 thermostat might be a good idea.

[jww426]

Is a 160 degree thermostat better for summer?
180 degrees is a good temp for an engine.
I live in Virginia.
thanks
JWW

[RECHRGD]

180 is what most people use all year......

[c00nhunterjoe]

For max performance, 160. I personally run the 160 in everything, especially if you have iron heads.

[alfaitalia]

The stat only defines the point that the coolant starts flowing through the radiator...max temp is defined by the point the fan starts spinning full bore (or turns on in the case of an electric fan). The only time the stat controls running temp is on the open road when it closes to stop over cooling. So if you want to run your engine cooler when not on the highway, get a bigger radiator or a bigger fan or a fan clutch that locks up at a lower temp. A cooler temp stat will have minimal effect. Bear in mind that the hotter it runs without over heating the more efficient it will be (like a Charger owner would care about that!). On a modern car fitting a lower temp stat will throw fault codes..so best avoided.

[c00nhunterjoe]

Ive never seen a car improve its time in the 1/4 by increasing the coolant temp.... and my modern hemi called for a 205 stat stock and i ran a 160 in that, picked up a tenth and just under 1 mph with no other changes. No codes. And if you do set a p0128, thats what a tuner is for. Making your engine run hotter is not the answer.

[jww426]

But for street driving isn't a 180 stat ideal?

[c00nhunterjoe]

If the car runs at 180, yes, thats fine for a cruiser.  If it runs 180 driving and gets hotter idling around, then looks at airflow and radiator efficiency.

[alfaitalia]

Ive never seen a car improve its time in the 1/4 by increasing the coolant temp.... and my modern hemi called for a 205 stat stock and i ran a 160 in that, picked up a tenth and just under 1 mph with no other changes. No codes. And if you do set a p0128, thats what a tuner is for. Making your engine run hotter is not the answer.

....more efficient....not more powerful/quicker. And don't forget, most of us don't take our Chargers anywhere near the track (especially in the UK where drag racing is not that popular) so a tenth (or even a second!) is neither here nor there!

[c00nhunterjoe]

Race engines run at their most efficient. Increasing the cooling temperature is used strictly for emmisions purposes.

[alfaitalia]

Race engines run at their most efficient. Increasing the cooling temperature is used strictly for emmisions purposes.

,

Really? Well any race/fast street type engines I have been involved with have been all about power and torque... efficiency (as in mpg) taking a poor second place. The o.p has not mentioned if he is racing his car or not.

Internal combustion engines operate most efficiently at relatively high temperatures, typically above 80°C - 85°C (176°F - 185°F). Wear on the moving parts is reduced and thermal efficiency is increased by operating at this temperature.

Lower engine temperatures result in inefficient combustion which causes increased fuel consumption, and increased wear with consequent reduced engine life.

However, if the engine temperature gets too high, boiling of the coolant leads to local steam pockets forming which severely reduce heat transfer in the affected area, usually the cylinder head, resulting in premature combustion of the fuel air mixture, also know as detonation or knocking, and ultimately damage to engine components (the cylinder head, valves and pistons).

[c00nhunterjoe]

Ok, my 2007 charger rt with a 5.7 hemi. It was a daily driver. NOT a race car by any means. Engine itself was unmodified. Swapped the 205 for a 160 stat. Used a diablo tuner to adjust the electric fans to the stat, increased timing, increased fuel curve. Went from 14.10s at 97mph in the 1/4 and 15/22mpg to 13.21@105  and 19/31mpg. So i lowered the coolant temp, made more horsepower, and increased my fuel economy. I also drove the car up to 185k on the origonal drivetrain and still talk to the guy i sold it to. It is well over 200k and going strong. If you feel you need to crank up the coolant temps to make the car run better, go for it. But you are wrong.

[alfaitalia]

Ok...that's sounds like good evidence...at least in that case. I will just leave these links for you perusal!   ....and I never said to crank up the temp just that there are negligible gains and potentially problems from reducing it too far below designed running temp.

http://www.superstreetonline.com/how-to/engine/impp-1001-colder-thermostat-increase-power/

http://www.tuneruniversity.com/blog/2012/04/low-temp-thermostats-whats-the-advantage/

I'm sure you can find websites that say the opposite (tbh I found a few but mostly relating to reducing detonation at high loads such as racing and not so much in street use) and that is what happens on the net...there are folks who can"prove"the Earth is flat! At the end of the day as I implied earlier the limiting factor in how cool your engine runs is the cooling capacity of the radiator and fan operation not the thermostat. The thermostat's sole purpose is to get the engine hot quickly, and keep it hot. Putting in a lower temp stat in the aim of better cooling is a myth.
I think I've dragged this out enough... lol. Thank you and good night!

[c00nhunterjoe]

So your 1st link is of a miata that dynoed a 192 vs a 160 stat and clearly stated that they left the tuning in for the 192 during the 160 test... well no kidding the 160 performed less.... and the 2nd can be quoted as saying that at 160 degrees metal parts in the engine are "banging around". I think your arguements have proved my point.

[alfaitalia]

Lol....Nicely hand picked points. Let's just ignores the rest of the articles then! The Verdict in the first one was "Hotter engines make more power"....up to a point of course . And more importantly the main point of all my posts on this ....a thermostat sets a floor, not a ceiling on engine temperatures.

[c00nhunterjoe]

The hotter engine in the miata made more power. Yes, 100% agree. They used the programming for a 192 coolant temp and tested at 192 degrees and then at 160 degrees on a 192 program. Are you seriously arguing that?

[alfaitalia]

No, of course not.....but the OPs Charger will have no programming to alter so will have no advantage of fitting the lower temp stat.

He asked
"Is a 160 degree thermostat better for summer?"...to which the answer (assuming a stockish carb engine) is no as it wont affect the top running temp of the motor...only stopping it get too cool on the highway.

If you don't agree that fine and I bow to you superior knowledge ! I'm out!

[BSB67]

If you are running cooler water temps in the cool weather and not overheating in the summer, you probably don't have anything you need to worry about.  Normally, or at least in the mid west states. if you cooling system is good, your thermostat opening temp will give you a water temp of that same temp rating all year round within a few degrees, with some exceptions.  if your cooling system is more marginal, you will see more temp increase in the hot weather.

[c00nhunterjoe]

No, of course not.....but the OPs Charger will have no programming to alter so will have no advantage of fitting the lower temp stat.

He asked
"Is a 160 degree thermostat better for summer?"...to which the answer (assuming a stockish carb engine) is no as it wont affect the top running temp of the motor...only stopping it get too cool on the highway.

If you don't agree that fine and I bow to you superior knowledge ! I'm out!

Sigh, no programming? You mean like carb jetting, base and total timing, ignition curve?