Temp too high ?

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MAPS

FABO Gold Member
FABO Gold Member
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It's been a while since I've had to come and seek out the experts here.
My dilemma is the car's temperature while driving about town. Summer time.
What would be considered too high which can possibly cause engine problems, overheat, etc. Thus needing to pull over and shut the car down and wait for it to cool down.
What is considered as "normal" or acceptable temp.
Again thank you all for any replies or info on the matter.

MAPS

P.S. I just realised you might want to know a little about the engine...
340 6bbl
Solid cam 580 lift ( give or take a few degrees) 10 . 5 comp. Headers.
4 speed with 4.10 rear (489 posi track)
 
It's been a while since I've had to come and seek out the experts here.
My dilemma is the car's temperature while driving about town. Summer time.
What would be considered too high which can possibly cause engine problems, overheat, etc. Thus needing to pull over and shut the car down and wait for it to cool down.
What is considered as "normal" or acceptable temp.
Again thank you all for any replies or info on the matter.

MAPS

P.S. I just realised you might want to know a little about the engine...
340 6bbl
Solid cam 580 lift ( give or take a few degrees) 10 . 5 comp. Headers.
4 speed with 4.10 rear (489 posi track)
I assume you are seeing a high reading on your stock temp gauge. Do you have an infrared thermometer to see what the actual temp is?
 
It's been a while since I've had to come and seek out the experts here.
My dilemma is the car's temperature while driving about town. Summer time.
What would be considered too high which can possibly cause engine problems, overheat, etc. Thus needing to pull over and shut the car down and wait for it to cool down.
What is considered as "normal" or acceptable temp.
Again thank you all for any replies or info on the matter.

MAPS

P.S. I just realised you might want to know a little about the engine...
340 6bbl
Solid cam 580 lift ( give or take a few degrees) 10 . 5 comp. Headers.
4 speed with 4.10 rear (489 posi track)
How high are you seeing? A healthy cooling system and a 15# cap the coolant doesn't boil until 257° or so. Most systems with 180° stats won't go past 220° or so. What radiator are you running? Shroud? Fan? thermostat?
 
IMHO

Thermostat temp to 220 would be normal.
If using a stock gauge, center to just left of center would be "normal"

ideling in gear (assuming automatic) a few ticks to the right of center.


QUESTION...

Does your temp just keep rising or does it stabilize at some temp ideling in gear.


Assuming you have a matched cooling system.


  1. Water pump is the correct one for the pulleys. ie. Water pump is for AC cooling and pulleys are also sized for AC cooling.
  2. Fan is sized correctly and for the propper cooling level as the WP and pulleys
  3. Radiator is sized correctly for the cooling level (or larger)
  4. Shroud, fan blade spacing, etc
 
I pose this scenario to those who have engines that run too hot [ whether they are actually too hot or the owner is just worried about it ]. Especially pertinent with 4.10 gears which will have high engine rpms on the freeway.
"The engine produces twice as many power strokes [ that create heat ] at 4000 rpm as it does at 2000 rpm, but it has no increase in volume of coolant & radiator size to cope with the doubling of the power strokes"
 
but it has no increase in volume of coolant & radiator size to cope with the doubling of the power strokes
But it is moving 2x the coolant through the radiator, and it is assumed that the airflow is sufficient at road speeds.
 
If it starts going over 230 I will get concerned, as soon as it goes over 235/240 I will shut the engine down, nasty things can start happening when you get much over 240. Anything below 225 should be fine, you should see no damage, but to be honest I prefer to keep the engine temp at 200 at the most. Around town I like to see, light to light lots of idling, 200 maybe 210 max in the middle of the summer, if the car is moving above 25/30 MPH close to 185, or just over the 180 thermostat I like to run on street cars.
 
Post#6. Yep it is moving at 2X the speed. But is it removing 2X worth of heat generated. Every car I have owned from the pre-computer era that just had a mech fan got hotter on the freeway.
 
Every car I have owned from the pre-computer era that just had a mech fan got hotter on the freeway
No argument there but the increased air flow and water flow only allows it to raise it a small manageable amount.
 
And now here comes 12 pages of totally non related bullcrap the OP never asked about.
 
If you're using the stock gauge as a reference, throw an aftermarket gauge in there to verify what you're reading is accurate first. Unless of course you're puking coolant or dieseling. Then you need to get to the bottom of the overheating issue.
 
220 will vaporize moisture in oil and help the PCV remove it from the oil. 230-235 I want a mile or two stretch of open road to cool it down, I don't like to shut it off unless it quits cooling.. My stat is a 180 so my norm 180-220 with A/C on
 
I've only had the increased temp with increased speed when Ive had a plugged up radiator.
 
P.S. I just realised you might want to know a little about the engine...
340 6bbl
Solid cam 580 lift ( give or take a few degrees) 10 . 5 comp. Headers.
4 speed with 4.10 rear (489 posi track)
360 4bbl here with alloy heads,; Also a 4speed; but with 3.55s now, (used to run 4.30s. )
First cam; I ran was the ~249@.050(292/292/108mopar) ~.540lift and and at 11.3Scr
Second cam: I ran a 223@.050, .539/.549 lift IIRC, initially also at 11.3, bur reduced to ~10.7Scr
Third and current cam: 230@0.050; .549/.571lift, at 11/1
all were FTHs

My system runs at 207*F by IR gun, at the stat house. Once there it doesn't move, thanks to a viscous clutch with a thermostatic control, and a fresh-air intake system.
What would be considered too high which can possibly cause engine problems,
Well they say that oil is usually good to ~240, so
If the pistons or rings don't swell up and lock the engine, I suppose 240 would be the upper limit........ but I wouldn't test it, lol. I run a 7-quart oil pan for a hint of protection.
240 in the oil might not be 240 in the coolant.
My rad is out of a 73Dart 318-A/C car. Even the patches on it have patches. To be fair, I had it boiled-out in 1999........ lol.
 
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