How hot is too hot?

[69BlackChargerRT]

I was wondering how hot is too hot for the engine temp?  I am running a stroker 468 ( 555hp, 565 torque dyno) and have a 24" Be Cool radiator with dual electric fans in my 1969 Charger R/T.  I have a 195 degree thermostat but am getting readings of 200-215 degrees on my temp gauge.  This is still within the "safe" area as indicated on the gauge, but sometimes it spikes to the 230 degree range which is at the end of the "safe" range.  I am only driving on cool days ( no higher than 80 degrees F).  I had my gauges rebuilt but don't really know how accurate they might be now.  If they are accurate, is this too hot for this type of motor or is it normal?  Is there a way to check the temp by bypassing my temp gauge?  Would it be wise to get a lower temp thermostat?

Thanks in advance for your help!

[RECHRGD]

Your running Too hot for my taste!  I like the 180-190 range and seem to lose power above that.  I run a 180 degree high flow stat and a miloden high volume pump with an aluminum radiator, aux, electric fan (only kicks on in traffic on a hot day) and a clutch type fan on the engine side w/ no shroud.  Your making more hp than me but you should still be able to bring the temp. down.   Bob

[Plumcrazy]

Would it be wise to get a lower temp thermostat?

Thanks in advance for your help!

I would put a 180* in it and see what happens.

[69BlackChargerRT]

Will do and thanks for the advice.  I will let you all know the results!

[phat69charger]

I know it's been debated on this forum about what temp thermostat to run in your engine and what Temp is best for the engine, Well my view on it is that heat and friction are the primary killers of a engine, so if you keep it running cool your engine will last a while.

I know that plenty of the members on this forum say they run 180 degree thermostat's and they don't have any problems with over heating, and the factory recommendation is 180 or so Thermostat, but  most of us don't have engines built to factory spec's nor do we run gear ratio's that will make the engine operate at the ranges the factory intended and we usally don't run the engines under the same conditions you would a daily driver.

So what machine or engine do you know of that runs better or last longer when running hotter, cooler gas burns better, the hotter the item gets the more it expands as it expands the smaller the tolerances, what's good about that?

I know it's been said that you get a cleaner emissions running the engine at that temp, well I sure don't care about cleaner emissions whose driving your car your grandmother? and cars before 1971 didn't have emissions.

[Nacho-RT74]

Your running Too hot for my taste!  I like the 180-190 range and...

That is around half of the way of gauge... right ?

[69BlackChargerRT]

That's correct.  They make a 160* high flow thermostat which would keep the temp low (below the safe zone on the temp gauge).  That wouldn't be too cool as opposed to a 180* would it

[tan top]

i would fit a separate good quality mechanical temperature gauge first then a 180 degree thermostat , and then see what is happing.      it is not running  lean at some point, idle etc or  is it  or timing, just a thought.  180-190 degrees is best in my opinion.

[grouseman]

Changing your thermostat won't change a thing.  Your 'stat is already wide open and you're hitting 215-230 (if those temperatures are indeed accurate).  The thermostat only controls the MINIMUM operating temperature, not the maximum.  Get a better temp guage, and if it confirms the hot readings, then you need more airflow or cooling capacity.  How is the pump?  Not hampered by a slower pulley set, is it? 

grouseman

[daytonalo]

I HAVE TEN CARS , AND ONE RACE BOAT , NO STATS IN ANY OF THEM DURING SUMMER MONTHS . AS MENTIONED EARLIER, KEEP THE GOD DAMN HEAT OUT AND THE ENGINE WILL LIVE .JUST A SIDE NOTE , THE HOTTER THE ENGINE , THE HOTTER THE OIL SO YOUR ENGINE IS LESS PROTECTED AND A HYDRAULIC LIFTER WONT STAY PUMPED UP TO CAM SPEC'S . TRUST ME I KNOW ,I RUN A 540 -700 HP ALL DAY LONG @ 5000 RPM !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

[69BlackChargerRT]

I'll be working on it this weekend.  I am going to sub a new thermostat in as well as use a external temp gauge.  Maybe (hopefully) it is just my "rebuilt" in dash temp gauge.  If not, I dunno.
Thanks for all your all's advice!

[daytonalo]

GO OUT AND SPLURGE AND BUY A DIGITAL LASER  THERMOMETER, THIS WAY THERE IS NO GUESSING

[grouseman]

Digital laser thermometer?    

Step 1:  Hook up a decent temp gauge, either mech or elect, and confirm the temp readings. 

If things are still hot, test the thermostat opening temperature, and that it is opening fully at the rated temp.  If you buy a new t'stat, also test it before installation. 

You need a t'stat.  Running below 180 is terrible for a street engine - many reasons. 

Is your rad known to be good - clear of buildup in the tubes?  Even a little can hamper heat transfer substantially.  Inspect & rod if needed. 

Is the anti-collapse spring in the lower rad hose? 

Are the elect. fans coming on? 

Is the pump actually flowing good volumes of coolant?  Although not a Mopar issue, the Olds pumps would not flow at all unless their backing plate was there and properly clearanced.  I'm just saying don't take anything for granted. 

Under what conditions are you getting this temp issue? 

grouseman

[dodge freak]

Yeah I seen those digital laser thermometers , the food store has a few they point it at the meat in the cooler and it show what temp. it is, really neat. Might work for a motor too. No wires , just point the beam and it shows the temp. Where you buy one and how much I do not know. If its like most new stuff in 10 years they have it much cheaper and better. This is why I still have my 15 year old T V , ha ha.

[69BlackChargerRT]

Well, I swapped my thermostat for a 180* hi-flow.  There is little to no build-up of sludge or corrosion in any of the radiator hoses, the coolant is still a "new" green, and the fans are kicking on at about 200*.  The temperature stayed about the same, maybe a little lower due to the fact that the thermostat opened at 180* instead of 195* but eventually, the temp found it's way up to 210-220*.  Outside air temp was about 81*F. 

I guess, if I change my fan thermostat to kick on at a lower temp, it would/might keep the temp down sooner and longer.  I went to get a test gauge/thermometer at the auto store, and the guy said the laser reads + or - 10* when you aim at the radiator.  Other than that, just buy a cheap temp gauge and hook it up to the sending unit to test the accuracy of my stock rebuilt gauge.  I am going to do that tonight, so keep the fingers crossed it is just the gauge at this point.

[dodge freak]

It would not hurt to have the fans come on around 185 . If they wait to long it might not cool it off. B T W how are the fans, do they push air and are in front or do they pull the air in and are behind the rad. Are you sure they both spin the same way and if so it should either push the air if in front or pull the air in if they are behind. This is very important.

[grouseman]

Is the water pump known to be good, and putting out a strong flow?

Are your mechanical advance and vacuum curves operating correctly? 

You said you had a 24" rad - why do I seem to think that 28" is the width for the factory big block rad?  And do you have it blocked so that all air goes through the rad, and that the fans are flowing correctly? 

Don't give up, there's a solution out there somewhere. 

grouseman

[Roppa440]

I have been through all this myself.

It is down to cooling capacity. Nothing to do with the thermostat. But I will mention one thing about thermostats. Run a 180 degree. Why? Below that temp you make more power but engine wear increases dramatically. Above that temp wear resistance is much better but power suffers. 180 degrees is a good compramise.

Now back to the problem.

Make sure your electric fan is getting full battery voltage. Measure the voltage across it while it is running. Connecting it directly to the alternator output or +ve terminal of the battery (same thing) via a fused relay is the best way to power it.

Second. Make sure the fan is big enough for the job and that it has a shroud.

Third. Make sure the airflow into the front of the radiator is clear of anything that might deflect airflow such as the licence plate.

Forth. These aluminium radiators sure look trick. But guess what? They are rubbish at cooling unless they are painted black. I seem to remember from Physics lessons that there is a huge difference between the heat radiated from a silver type surface than from a matt black surface. About 30% difference I think??

Checking and adjusting these simple things got my engine temp down from 240 (boiling over) to 180-190 degrees. If these tricks don't work then maybe your radiator is just not big enough?

[Crazy440]

The green, in the rad liquid, is antifreeze.  Great for the winter but not much help in the summer.
When Spring hits, I dump the antifreeze and put in straight water, with one bottle of Water Wetter.  I'm running 450 rwhp, a 28 inch three core rad, with an electric fan.  On the hottest day, in Summer, in stop and go traffic, it never gets above 190.  I've used this setup for 4 years now and my rad is as clean as the day I had it recored.
My 2¢
Crazy

[Chryco Psycho]

I disagree , with straight water 2 problems happen 1 the block will rust decreasing the effeciency of the cooling system
second the boiling point is lowered which helps nothing & you are more likely to get steam between the heads & coolant again decreasing the effciency of the cooling system
I have not found electric fans to be a good solution , in virtually every case a vicous fan & shroud will outperform any electric setup   

[Crazy440]

http://e30m3performance.com/myths/more_myths1/Water_Wetter/water_wetter.htm

http://www.water-cooling.com/articles/waterwetter/waterwetter.php

Water Wetter is a unique wetting agent for cooling systems which reduces coolant temperatures by as much as 30°F. This liquid product can be used to provide rust and corrosion protection in plain water for racing engines, which provides much better heat transfer properties than glycol - based antifreeze. Or it can be added to new or used antifreeze to improve the heat transfer of ethylene and propylene glycol systems. Designed for modern aluminum, cast iron, copper, brass, and bronze systems.

[grouseman]

have a 24" Be Cool radiator with dual electric fans

Describe the rad; how thick or how many tubes are in it? 

And I second the flat black theory; much more effective at transferring heat than shiny silver. 

[69BlackChargerRT]

Well, still no joy.  Here are a couple of pics to give you all a visual of my set up.  It is a 26" Be Cool Aluminum dual core radiator with dual electric fans.  The kick on at 195* but I am looking at making them kick on at 180*. They pull and don't push (they have relays and inline fuses).  I am getting another gauge this weekend to double check my gauge.  I have been busy and not had a chance to get it done yet (anyone else run into that problem???)

Would painiting it black really help that much???

[firefighter3931]

The BeCool rads aren't known to be that great....many still have problems after this supposed "upgrade". 

Fwiw, my bud just installed a Northern brand aluminum rad on his blown 440 which was forever overheating.  Kev said the new rad works like a charm....idled for 15minutes and never got over 180* with the electric fan OFF ! 

With the old OEM 3 core 26in it would hit 220* doing the same test with the fan ON. I'd say that rad works pretty good. Anyone who runs a roots blower knows how much heat those monsters generate....if a $175.00 rad can tame that beast....cooling a naturally aspirated stroker should be no problemo. 

Ron

[DanishDude]

Would painiting it black really help that much???

Nope, sorry guys, it won't. 

While it is true that a black surface will be much more effective at radiating heat away from a heatsink (or car radiator) as compated to one with a raw, reflective finish, painting it black only makes a noticeable difference if:

A) The surroundings of the radiator are much cooler than the radiator. This is only true to some degree in a car engine, since the temperature differentials are rather limited after all, and the engine block by definition is hotter than the radiator.

and

B) A majority of the heat loss from the radiator is through radiation. This is not the case in a car. A very large fraction of the surface area of the radiator is enclosed 'within' itself, so pretty much all the heat removed is through the air being forced through and heated along the way.

Put differently, then the black paint will only make a noticeable difference for the amount of heat removed with all fans off! On the other hand painting the radiator may obstruct the airflow and isolate the metal surface from the cool air, thus having a direct negative impact.

I believe the 30% difference mentioned previously are between painted and unpainted aluminium heatsinks in still air. I have yet to see serious semiconductor electronics with cooling tunnels, where the heatsinks are painted black. The difference is negligible and may even be negative.

Frank.