Thermostat question

[markmurfie]

nuke it all

If that is what ends up happening. It was worth it just to get your detailed explanation.

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[Higgs Boson]

:faint:
NOOOO! lol.. I will attempt a positive and constructive response.

"full flow through the radiator at all times, which is too fast and will cause less heat loss."

No dude. Please don't spread this BS around or Ill have to call in the Higgs Boson :eyebulge:. We are all on same team trying to understand our cars and thermodynamics but this statement is bunk.
Where did you get that quote from?:barf:

opcorn:
Quick thermodynamics clarification:
Heat and Temperature are two different concepts.

Heat == Thermal Energy == the total energy of a mass.
Temperature is average molecular motion energy.

An iceberg has more thermal energy than a single lit match.:eyebulge:

Thermal energy does not flow unless there is a difference in temperatures.
Greater difference == great thermal flow.

For a constant ambient air temperature of 80F:
If you have 80F coolant and flow 0 or 1000 or 1000000 gph thru a radiator, your thermal flow will always be 0. Yup zero, zilch, nada, nothing.
No temperature difference, no thermal (heat) flow.

In this case, assuming 80F fixed ambient conditions, you must change the temperature of the coolant thru the radiator. The higher the temperature in the coolant, the more Thermal Energy(waste Heat)(Watts)(Horsepower) you can get rid of.
Now, if you suddenly stop the flow thru the radiator, the coolant in the radiator will eventually match the ambient temperature of 80F. As the temperatures in ambient and coolant equalizes to 80F, the rate of thermal energy flow reaches 0!
So we are back at 0 temperature differential == 0 thermal energy flow (0 heat flow).

So when the temperature differential goes to 0, the heat flow goes to 0.

0 temperature differential = 0 thermal energy flow = 0 HP = 0 W

If you then very very slowly increase flow, the coolant coming out will be close to ambient 80F temperature. THIS IS BAD! lol..
Thus, getting the coolant as close to ambient as possible requires decreasing the coolant fluid flow as close as possible to 0: and thus the thermal flow to 0!
0 fluid flow = 0 thermal (heat) flow.

Thus higher coolant flow = higher thermal energy flow.
Maximum thermal flow from engine to ambient is NOT with lowest exit temperature from cold side of radiator!
Maximum thermal flow from engine to ambient is with HIGHEST coolant temperature possible entering the radiator. After you achieve this, the engine will COOL dramatically because it can not generate enough waste heat to maintain the high coolant temperatures!

If you take the thermostat out, coolant temperatures become purely based on the amount of waste heat generated. Waste heat is purely a function of total HP generated.

I have tested running WITHOUT a thermostat and it takes forever to get up to temperature and requires excess fuel and deposits more carbon on the plugs. Great for horsepower in the short run, but not sustainable unless you like carbon deposits acting like glow plugs causing detonation.
And yes, CHT and coolant temperatures where way down in the 136F range after 15 minutes of idling and the cats were pretty warm even at idle with all the unburned gas coming thru. I figure 10 minutes of WOT blasts in that condition would probably overheat the crap out of the cats.

The purpose of thermostats are to artificially limit the flow of coolant and thus the thermal flow AWAY from the engine to keep the engine operating at a minimum temperature range. This keeps the oil and mechanical systems operating at their designed operating temperature and avoids excess thermal cycling.

Don't take my word for it. Go pull your tstat and grab several beers, a pencil and set your dash to gauge mode. Watch your CHT.
When I did this, the CHTs stayed way too low for sudden WOT blasts.
I concluded by the 3rd beer that no tstat might be a great way to burn the cats out, bust the oil pump at WOT, foul the plugs, and waste a bunch of gas.
:cheers:

mod, thread cleanup?

good post.

what engine did you use to test the no thermostat temp rise?

I do not run a stat in my race car because I want to run down the track at 120 degrees, plugs look great! never broke anything either.

the 170 keeps the coolant much cooler but still no where near 136....and the oil temps still heat up to an appropriate level as well, this is not a dramatic modification.

Have a look at this picture:
If you had tested your thermostatless engine with the mustang, it would not have made much difference in fueling as it is already targeting stoich in open loop by 50 degrees and once the O2 sensors temps come to temp, which doesn't take long with the built in heaters, the car goes into closed loop anyways and corrects back to stoich no matter what the open loop table says.

Running super cold, which does not apply to these cars, has more of your described implications on a carburated car, IMO, even though these cars still heat up just as quickly with a 170 as they do with a stock thermostat, just to 185 operating temp instead of 215.

1.0 equals stoich (14.1 AFR)

 

[markmurfie]

If I'm not mistaken, when I changed my thermostat it formed the seal between the engine and housing. The instructions mentioned being careful to not over torque the bolts and damage this seal. You would need some o ring in order to run no tstat. Anyone have a site I can order one? Or info on how to run it with out a tstat. I will use my car as a test mule to see what happens when you run no thermostat.

 

[Higgs Boson]

If I'm not mistaken, when I changed my thermostat it formed the seal between the engine and housing. The instructions mentioned being careful to not over torque the bolts and damage this seal. You would need some o ring in order to run no tstat. Anyone have a site I can order one? Or info on how to run it with out a tstat. I will use my car as a test mule to see what happens when you run no thermostat.

The even flo stat comes with a loose o ring, you might find out what that part number is or size.

 

[sigintel]

Higgs, you have inspired a beer drinking event... Uh I mean tstat round up and test.
Ive got three tstats and of course no tstat so four cases that coukd be logged.
I didnt really time anything when I pulled the tstat, just got bored by 3rd beer and shut it down so I could put tstat back in.
Changing tstats on hot motor sux.
So question, can you think of a way of forcing tstat open after test so I can run garden hose over radiator and cool the motor down quick at end of test?
Need something like a switchable tstat bypass.
Either that or more time n beer....

Damn, IR surface temp gun I could have shot the cats during the 0-50F rise.
Weld on tcouple would be even better.
Im such a slacker...

Higgs, what logging hardware you like for 15-16 Coyotes?

 

[sigintel]

For easy no tstat you can cut the valve parts retainer and just use the body with an oring.

 

[Higgs Boson]

Higgs, you have inspired a beer drinking event... Uh I mean tstat round up and test.
Ive got three tstats and of course no tstat so four cases that coukd be logged.
I didnt really time anything when I pulled the tstat, just got bored by 3rd beer and shut it down so I could put tstat back in.
Changing tstats on hot motor sux.
So question, can you think of a way of forcing tstat open after test so I can run garden hose over radiator and cool the motor down quick at end of test?
Need something like a switchable tstat bypass.
Either that or more time n beer....

Damn, IR surface temp gun I could have shot the cats during the 0-50F rise.
Weld on tcouple would be even better.
Im such a slacker...

Higgs, what logging hardware you like for 15-16 Coyotes?

I just use HPTuners on everything I tune.

 

[Jpjr21]

Is there any issue running a lund tune without a cooler thermostat?

 

[GSLSE20B]

Is there any issue running a lund tune without a cooler thermostat?

The fans are switched on at lower temps . You may see them on more often than stock .

 

[Jpjr21]

I might see what my local napa/vatozone has and see how it does.

You ever get one? The vatozone only has 160 or 180.

 

[GSLSE20B]

Stock is stamped 180 . The 160 is a different type of bypass

 

[dubster99]

You ever get one? The vatozone only has 160 or 180.

Nope. Mine didn't have any. I ordered a Reische 170 from lethal. I've been running my lund tune without, and the fans are on all the time.

 

[mustang_racer]

I replaced my thermostat Sunday. But before I did, on Saturday I took my car for a 20 mile drive thru town and on the highway. It was 80 degrees outside Saturday. My Head temps were 208-210. On Sunday morning I replaced the thermostat with a Reische 170. I used the gallon ziplock bag method to catch all the coolant that came out. I was doing great until the bag snagged something sharp... Then I had about 2-3 cups of coolant all over the place. So I replaced that coolant with waterwetter and distilled water. I let the car idle and i burped the system etc etc. It was about 9:30 am when I finished. Took me about 30 mins (counting the mess cleanup). It was still about 70 degrees outside, So I decided to wait until afternoon to drive the car.... It so happens that it was 80 degrees again when I went for my ride. I took the exact same route I did Saturday. My Head temps were between 190-194. I am very satisfied with my thermostat.
I know this is not by any means scientific. These are just the results that I have experienced. I did not expect any power improvements from this. Living in an area that hardly ever gets to freezing and summer is 100+, I didn't like seeing the high temps on the gauge. (last year in the summer I saw 217 and did not like that!) For me, This is a worthwhile price to pay for a little bit of "peace of mind" that my car is not running hot.

 

[evo8904]

I replaced my thermostat Sunday. But before I did, on Saturday I took my car for a 20 mile drive thru town and on the highway. It was 80 degrees outside Saturday. My Head temps were 208-210. On Sunday morning I replaced the thermostat with a Reische 170. I used the gallon ziplock bag method to catch all the coolant that came out. I was doing great until the bag snagged something sharp... Then I had about 2-3 cups of coolant all over the place. So I replaced that coolant with waterwetter and distilled water. I let the car idle and i burped the system etc etc. It was about 9:30 am when I finished. Took me about 30 mins (counting the mess cleanup). It was still about 70 degrees outside, So I decided to wait until afternoon to drive the car.... It so happens that it was 80 degrees again when I went for my ride. I took the exact same route I did Saturday. My Head temps were between 190-194. I am very satisfied with my thermostat.
I know this is not by any means scientific. These are just the results that I have experienced. I did not expect any power improvements from this. Living in an area that hardly ever gets to freezing and summer is 100+, I didn't like seeing the high temps on the gauge. (last year in the summer I saw 217 and did not like that!) For me, This is a worthwhile price to pay for a little bit of "peace of mind" that my car is not running hot.

Yeah, the install isn't bad at all. I dynoed mine on Saturday. I did 7 pulls within about 30 mins. My CHTs averaged 188 to 195 degrees; it was 93 degrees in the dyno bay.

 

[sigintel]

Yes. The base radiator seems to do fine for stock tune and engine. I've held the rpms above 4k(majority of the time) with the 170 for over 30 min and did not see more than 195* cht unless I was going up a long hill.I'm sure a pp car would do even better.

As for IAT I find they get high in stop and go traffic. Once you start moving again they can remain high for a while. The way to correct this is stay in lower gears longer to open the throttle and get more air flowing through the tube. When you do that they drop very quickly.

How high on your IATs? ever see 160?

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