Overheating issues

[cdr]

let me guess..... are you attempting to run a 185-190* Stat because the parts counter guy said so ?

WHAT TEMPERATURE THERMOSTAT ARE YOU ATTEMPTING TO RUN IN THIS APPLICATION ?
That being...
with the BIG Tans Cooler and the A/C Condenser BOTH in front of the Radiator ?
and remember also
Timing can have a dramatic effect on how much of the Cylinder wall is exposed to peak combustion temps to heat sink and cooling system loads.


Chase your tail all you want, but until you install a 160* Thermostat as a start point, the latent Heat will continue to build. And even a 160* may require a 1/4" bypass hole drilled in it.
BTW,
FORGET what the Parts counter dorks say is the "correct" temp thermostat, you can NOT run anymore than a 160 Stat.

I'm sorry that my post has you so upset, that was never my intention.  To answer your question, I am running a 180* thermostat because that is what 70-80% of the people on this forum advised when I used the search function and looked through old threads, not because I went to Autozone looking for advice.

I did a little further testing this morning and fired the car up cold without the radiator cap.  Once it reached 180* it maintained that temp indefinitely.  Coolant flow looked great, but it is too fast.  At 700 RPM it works fine but when I increase to 1200 RPM it is blasting water through the radiator far too fast for there to be adequate time to cool the water.   I can only imagine what it is doing at 2500-3000RPM (cruise speed).   Looks like White and Red 69 was correct above when he said the high volume pump from Mancini could be the problem.   Where is the best place to source a Factory flow A/C style pump?   Thanks everyone for your input.    

Most EFI set ups need 180 tstat because of the CLOSED LOOP fuel control temp is usually 160, in cooler temps the EFI would go in & out of closed loop.
to much water flow is NOT the problem, air flow or your new radiator is plugged up.
also as Challenger 340 said ign timing is VERY important , what is your set up as
What pulley set up do you have, Ratio ?
what radiator ?

it gets 108 here in Southeast Texas, I have AC, 512ci big block & my car will run 180ish ALL day long,100 mph or sitting in traffic

[69wannabe]

I tried a 180 high flow in my 493 and the gauge seemed to float around half way or basically straight up in the middle of the gauge so went to a 160 high flow stat and it was a bit better but still seemed to be high for my taste. I went and bought a cheap t-stat a the parts store and clipped it and now it has just an open hole (gutted) basically and now it never gets above 190 degrees. I also replaced the old torque style fan clutch with a HD thermostat style fan clutch but my car doesn't have a transmission cooler or A/C on it. I an running the milidon water pump and the Mancini aluminum housing on my car also with a factory style 3 row radiator. Hope you get it figured out soon...

[garner7555]

let me guess..... are you attempting to run a 185-190* Stat because the parts counter guy said so ?

WHAT TEMPERATURE THERMOSTAT ARE YOU ATTEMPTING TO RUN IN THIS APPLICATION ?
That being...
with the BIG Tans Cooler and the A/C Condenser BOTH in front of the Radiator ?
and remember also
Timing can have a dramatic effect on how much of the Cylinder wall is exposed to peak combustion temps to heat sink and cooling system loads.


Chase your tail all you want, but until you install a 160* Thermostat as a start point, the latent Heat will continue to build. And even a 160* may require a 1/4" bypass hole drilled in it.
BTW,
FORGET what the Parts counter dorks say is the "correct" temp thermostat, you can NOT run anymore than a 160 Stat.

I'm sorry that my post has you so upset, that was never my intention.  To answer your question, I am running a 180* thermostat because that is what 70-80% of the people on this forum advised when I used the search function and looked through old threads, not because I went to Autozone looking for advice.

I did a little further testing this morning and fired the car up cold without the radiator cap.  Once it reached 180* it maintained that temp indefinitely.  Coolant flow looked great, but it is too fast.  At 700 RPM it works fine but when I increase to 1200 RPM it is blasting water through the radiator far too fast for there to be adequate time to cool the water.   I can only imagine what it is doing at 2500-3000RPM (cruise speed).   Looks like White and Red 69 was correct above when he said the high volume pump from Mancini could be the problem.   Where is the best place to source a Factory flow A/C style pump?   Thanks everyone for your input.    

Most EFI set ups need 180 tstat because of the CLOSED LOOP fuel control temp is usually 160, in cooler temps the EFI would go in & out of closed loop.
to much water flow is NOT the problem, air flow or your new radiator is plugged up.
also as Challenger 340 said ign timing is VERY important , what is your set up as
What pulley set up do you have, Ratio ?
what radiator ?

it gets 108 here in Southeast Texas, I have AC, 512ci big block & my car will run 180ish ALL day long,100 mph or sitting in traffic

For the most part my car cools fine sitting idling it's at speed when it tries to get hot for the most part.  I had an OEM style pump laying around, so I stuck it on there this evening just to do a comparison.      You are correct, my EFI goes closed loop at 170* water temp. 

I think my timing would be in the correct range, but maybe not.       (I run 17-18* initial and 36* total.  All in by 2500 RPM)  I need to verify this with timing light to be sure it hasn't changed.

Another thing I plan to play with is my air/fuel ratio.  I could be running a little too lean at cruise which would be contributing to the problem.  Where would you guys like to see ideal cruise air/fuel ratio?

I posted a link to my radiator in my first post, it is this summit brand cross flow aluminum unit.     https://www.summitracing.com/parts/sum-380460

Thanks again for all the suggestions.     

[cdr]

What fan & Pulleys
are you running a vac advance ?

[garner7555]

What fan & Pulleys
are you running a vac advance ?

No vacuum advance.   The mechanical advance is locked out and I am running timing control with my EFI.   I bought this distributor from Firefighter Ron.      https://www.manciniracing.com/firradi.html

I measured my water pump pulley while I had it off.   If you measure to the bottom of the V groove then it is a 5" pulley.  I will try to measure the crank pulley later today.  The crank pulley is a 4 grove pulley and all 4 appear to be the same size.

I just recently installed this fan, and with it in high it seems to do a decent job sitting still idling.   Another thing to note is that the electric fan is pulling air back through the radiator, toward the engine, and not pushing air toward the grill as this would definitely cause an airflow issue at cruise speed.

[cdr]

take a picture of your fan & pulleys

[garner7555]

take a picture of your fan & pulleys

I was finally able to take some pictures, but the clearance is tight so it's hard to tell much about them.

[garner7555]

With very limited access to the Crank pulley, it appears to be about 6.5" in diameter to the bottom of the V groove

Charlie (CDR), You mentioned that your car will run 180* all day long with the A/C blowing regardless of driving conditions, even in over 100* outside temps.   This is exactly what my goal is.  We see a lot of mid 90* days here in Alabama and I want to be able to leave my A/C on high without worrying about the car running too hot.   If I need a new radiator and fan setup to achieve this then I am ok with that, but I do want to do my leg work to make sure I correct the actual problem rather than just throwing money at it in hopes that it will solve the issue.   I richened up the cruise air/fuel ratio but haven't had a chance to test it any yet.  I also need to check my timing with the light to verify that it is still where it was when I installed it.   Thanks to everyone for taking time out of your schedule to try to help me solve this issue.   

[cdr]

I set you a PM

[Challenger340]

Thermostat rating will have very little effect on how hot your engine gets....it only really controls the minimum temp you car will run at....ie the temp at which your coolant will start passing water through the radiator ....and therefore it will close on the highway to stop your engine being over cooled.. The max temp you engine runs at will be dictated by the size/volume of your radiator, the point at which you fan kicks in (if electric) or runs full bore (if mechanical). Stat has no control at all over how hot your engine gets in traffic or in very hot conditions.

And that is EXACTLY what we used to believe.... please note used to believe, theory being just that, the reality we've experienced somewhat different.  
Being a shop that built & Dyno'd literally dozens of BB Mopars, we have been exposed to a plethora of various issues, and yes, many cooling related once they later get installed in the Cars..... the base of the cure in 90% of these issues being the "start" point at which the cooling system begins to cool, and not playing catch-up within a too narrow cooling range to overheat.

Start point for us now when a cooling issue presents, is to direct the Customer to immediately install a 165*F stat , which the common denominator is always removing a 190-195*F stat, with then at least 6 out of 8 reporting problem solved, the one or two that it doesn't cure being other issues ultimately, although the 165* did help immensely.(changed Timing/Jetting, faulty W/pump internal passages)

Call it whatever you wish, I will digress to the early Chrysler service manuals on these Cars, which clearly called for 165*F Thermostats during summers/Hotter weather, and 195*F in winter/colder seasons
which,
as most people in Northern Canada used to experience back in the day, you could not even garner sufficient heat with a 165*F thermostat to clear the windows let be see to drive while freezing ur nuts off, Kinda shoots a hole in that entire "start point" maintaining Engine Temp thing ? Because 165*F in theory should be enough to at least clear a window to see ?

[Challenger340]

Thermostats are not a "switch" ?
They don't OPEN immediately/fully.... and they don't slam shut with a bang !

They open and close somewhat slower around their "target" temperature, "metering" to some extent as they do open or close.
IMO,
it is important to remember this NON "linear" aspect to application of the Cooling Systems "capacity" to cool, when addressing overheat issues.
As those who have ever run a 165*F thermostat can attest.... "normal" Engine Coolant temps are somewhat usually 10-15*F ABOVE the "target" 165*F of the Thermostat used anyway ? and we just haven't experienced any issues maintaining closed/open loop flip flops once warm ?
and IMO,
a BIG part of the problem attempting a 180-190*F T/Stats(200*F actual running) with a less than optimal Cooling System CAPACITY.

Question:
If you wanted to COOL DOWN 2 Gallons of Boiling Water(212*F) as fast as possible by ADDING 1 Gallon of Water, would you:

A.) ADD 1 Gallon of Water heated to 190*F ?
or
B.) ADD 1 Gallon of Water heated to 165*F ?

Simply speaking to the concept when diagnosing a cooling system overheat issue, of immediately moving to a 165*F T/Stat as a way to enhance Cooling System efficiency per same "volume" of coolant so it can be driven, then fine tune things like:
* Speed of the Coolant in the Radiator to allow Heat Exchange
* Pulley/Water Pump Speeds
and
* Air Flow through the Radiator itself if compromised by things like A/C Condensers, Trans Coolers, etc.

A $10. 165*F T-Stat change at the start "worked for us" is all I can say here ?

[b5blue]

I thought you were going to have a mechanical drive fan between engine and radiator and use the electric fan in front of your A/C condenser pushing air back as a flow boost.  But hey if that keeps temps okay that's a clean setup!  (I'm using a high flow 180 T Stat.)

[garner7555]

I thought you were going to have a mechanical drive fan between engine and radiator and use the electric fan in front of your A/C condenser pushing air back as a flow boost.  But hey if that keeps temps okay that's a clean setup!  (I'm using a high flow 180 T Stat.)

That was my original plan, but this fan wouldn't fit out front so I decided to give it a try as a puller.  Some members here have had good results using it as a puller (Firefighter Ron for one) so I am testing it and it does pretty well, better than the new clutch fan i was running.   My biggest cooling problem is at cruising speeds which is odd to me.      Thanks for selling me the fan.      If I end up not using it on the Charger then I will use it on another project.   

[garner7555]

Challenger340, I am more than willing to try a 165* stat.   I also respect how much knowledge you have about these engines (I have followed your builds and info on this forum for years).  I changed the pump to standard flow this weekend and I am going to test it first.  I would like to change one thing at a time to get an accurate evaluation of how much each thing helps.   

[cdr]

Link for screen
https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=2ahUKEwiKk6zbjtPhAhUNnawKHbh0BoIQFjAAegQIBBAC&url=https%3A%2F%2Fganofilters.com%2F&usg=AOvVaw0iuqKIhcut6Bjryx31finY

[cdr]

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[cdr]

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[alfaitalia]

Thermostat rating will have very little effect on how hot your engine gets....it only really controls the minimum temp you car will run at....ie the temp at which your coolant will start passing water through the radiator ....and therefore it will close on the highway to stop your engine being over cooled.. The max temp you engine runs at will be dictated by the size/volume of your radiator, the point at which you fan kicks in (if electric) or runs full bore (if mechanical). Stat has no control at all over how hot your engine gets in traffic or in very hot conditions.

And that is EXACTLY what we used to believe.... please note used to believe, theory being just that, the reality we've experienced somewhat different.  
Being a shop that built & Dyno'd literally dozens of BB Mopars, we have been exposed to a plethora of various issues, and yes, many cooling related once they later get installed in the Cars..... the base of the cure in 90% of these issues being the "start" point at which the cooling system begins to cool, and not playing catch-up within a too narrow cooling range to overheat.

Start point for us now when a cooling issue presents, is to direct the Customer to immediately install a 165*F stat , which the common denominator is always removing a 190-195*F stat, with then at least 6 out of 8 reporting problem solved, the one or two that it doesn't cure being other issues ultimately, although the 165* did help immensely.(changed Timing/Jetting, faulty W/pump internal passages)

Call it whatever you wish, I will digress to the early Chrysler service manuals on these Cars, which clearly called for 165*F Thermostats during summers/Hotter weather, and 195*F in winter/colder seasons
which,
as most people in Northern Canada used to experience back in the day, you could not even garner sufficient heat with a 165*F thermostat to clear the windows let be see to drive while freezing ur nuts off, Kinda shoots a hole in that entire "start point" maintaining Engine Temp thing ? Because 165*F in theory should be enough to at least clear a window to see ?

I bow to your superior knowledge...even if I don't really understand the reasoning. Once all the water it up to temp...say on a dino with not great airflow so no chance of over cooling....how does the rating of the stat have any bearing on the max temp the water gets to....it will be wide open whether it's a 165 or a 195 stat. Just trying to get my head around it!

[Challenger340]

Thermostat rating will have very little effect on how hot your engine gets....it only really controls the minimum temp you car will run at....ie the temp at which your coolant will start passing water through the radiator ....and therefore it will close on the highway to stop your engine being over cooled.. The max temp you engine runs at will be dictated by the size/volume of your radiator, the point at which you fan kicks in (if electric) or runs full bore (if mechanical). Stat has no control at all over how hot your engine gets in traffic or in very hot conditions.

And that is EXACTLY what we used to believe.... please note used to believe, theory being just that, the reality we've experienced somewhat different.  
Being a shop that built & Dyno'd literally dozens of BB Mopars, we have been exposed to a plethora of various issues, and yes, many cooling related once they later get installed in the Cars..... the base of the cure in 90% of these issues being the "start" point at which the cooling system begins to cool, and not playing catch-up within a too narrow cooling range to overheat.

Start point for us now when a cooling issue presents, is to direct the Customer to immediately install a 165*F stat , which the common denominator is always removing a 190-195*F stat, with then at least 6 out of 8 reporting problem solved, the one or two that it doesn't cure being other issues ultimately, although the 165* did help immensely.(changed Timing/Jetting, faulty W/pump internal passages)

Call it whatever you wish, I will digress to the early Chrysler service manuals on these Cars, which clearly called for 165*F Thermostats during summers/Hotter weather, and 195*F in winter/colder seasons
which,
as most people in Northern Canada used to experience back in the day, you could not even garner sufficient heat with a 165*F thermostat to clear the windows let be see to drive while freezing ur nuts off, Kinda shoots a hole in that entire "start point" maintaining Engine Temp thing ? Because 165*F in theory should be enough to at least clear a window to see ?

I bow to your superior knowledge...even if I don't really understand the reasoning. Once all the water it up to temp...say on a dino with not great airflow so no chance of over cooling....how does the rating of the stat have any bearing on the max temp the water gets to....it will be wide open whether it's a 165 or a 195 stat. Just trying to get my head around it!

Don't "bow" to anything, I certainly ain't no Einstein !

You can't understand the following ?

Answer this question:   If you wanted to cool down 1 Gallon of Boiling Water at 212*F as much as possible, would you
A.) Add 1 Quart of 195*F water ?
or
B.) ADD 1 quart of 165*F water ?
Again here, assuming the Radiator is doing it's job in Heat transfer ?

T/Stat controls minimum Engine operating Temp
T/Stat also controls minimum Temp at which the cooling system begins to take heat AWAY ? if it is working efficiently which is what we're trying to diagnose here I think ?

All I am saying is this,
while I also agree wholeheartedly with the "one change at a time" criterion for diagnostics to accurate assess progress ? In our experience the immediate default to the lower temp T/Stat on cooling system issues has proven for whatever reason, to be invaluable then moving forward with diagnostics, and makes it easier to diagnose other actual Heat Exchange issues present as the root cause.
ie:
Speed of the coolant too fast in the exchanger(time) for adequate BTU transfer
Air Flow through the exchanger for adequate BTU transfer
Insufficient secondary airflow around the Engine in the Engine Bay (the forgotten factor)

I know that the greater the differential temp across the exchanger should provide greater efficiency in transfer
I know that the less the differential temp across the exchanger should provide less efficiency in transfer
these are all givens.....
but I also know what's worked for us in practical terms versus theory, when presented by Customer cooling complaints, that being to Rec the immediate switch to a lower T/Stat, which surprisingly to us as well hastened whatever diagnostic root cure they eventually found ?

[AFD 792]

Garner,
Did you find a solution to your overheat issue? I'm going through the same exact thing now.

[garner7555]

Garner,
Did you find a solution to your overheat issue? I'm going through the same exact thing now.

Sorry for the delay, I don't get on very often lately.  CDR helped me get it straightened out.   I ended up replacing the radiator and fan.  I think my radiator got plugged with bits of junk out of the 50 year old block.  I run a filter in the top radiator hose now.  I used a 2 row radiator with 1.25" rows.  I also run a derale fan    https://www.summitracing.com/parts/der-16826         With this setup I can keep the A/C blowing and idle through a drive through in 95* weather even in high humidity.  I highly recommend this setup.

[b5blue]

Wow that fan draws 49.60AMPS. 

[cdr]

Wow that fan draws 49.60AMPS. 

True, but that is under full load, it is a pulse width controller set up. it ramps up & down as needed