Too Hot

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JD Erisman

JD Erisman

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Hello,
I’m looking for input, please. I have a 408/stroker, nothing crazy internally but enough to make good power. I have been using a 4-row round top radiator built for me by Glen Ray Radiators. The car always ran just below 180 on the AutoMeter mechanical gauge until the top tank developed a tiny pinhole leak. I sent the radiator back to Glen Ray, he did the repair and mailed it back to me.
Since then it runs hotter than before, it struggles to stay below 190, even in 60-degree temperatures. Driving at 55MPH (2,500 RPM) for 15-minutes it will climb to a little over 200. I was using a standard 180-degree thermostat, Hayden clutch with factory Mopar 5-blade clutch fan, and high output Miloden water pump.

After trying to diagnose the issue I replaced the cap, because it had a torn seal, with a made in the USA repop 16-psi cap, no difference in temperatures. I replaced the 180-thermostat with a high flow 180 after determining it didn’t open fully, no difference. I tested the Hayden clutch unit and it didn’t seem to be working correctly so I put on another, no difference. I replaced the cheapest and easiest first, one at a time as I didn’t see improvement. I didn’t make all of those changes in a short time span, but over a year-long period but my efforts were nothing but a shotgun blast at attempting to solve the problem by throwing parts at it. As I replaced those parts I kept telling myself, “it ran cool with this before so I can’t believe it’s the problem.” I didn’t listen to my own thoughts.
I cannot believe, or understand how, Glen Ray would have inadvertently done something that would cause the high temperatures and the coolant is definitely flowing through the radiator so I don’t think it is blocked. The bottom radiator hose is hot but not as hot as the top hose and the coolant level is good. Should the bottom rad hose be noticeably cooler than the top hose? The heater blows very hot air and the thermostat housing has a temperature close to the temp gauge so I’m sure the gauge reads correct.
Any ideas of what I should try next? Any help is appreciated, thank you.
 
What else was changed besides the radiator repair? If the answer is nothing, Then I'd call Glen Ray back.
 
I had a Rad shop put bungs in my be-cool rad. I had the same over heating problem. What I found was the radiator tubes were expanded from possibly being over pressured when pressure testing. This restricted air flow. Replaced the rad and it ran cooler then it ever did. Check the radiator air flow. If he repaired it he pressure tested it. Does not take much pressure to ruin a good radiator. New employees make mistakes.
 
Hello world, the car is not overheating, 240 would be over heating
200 is not hot...today's fuel dictates a 195 degree min operating temp, 60% water 40% antifreeze, a bottle of coolant conditioner, a high flow 195 degree t stat and a blocked manifold heat control crossover. Running colder than 195 causes excessive wear and the oil never gets a chance to keep clean. However please follow the old school thinking as nothing we have learned in 50 years of going very fast counts.
PS
Car came from ma mopar with a 192 degree t stat
 
Oldmanmopar said:
I had a Rad shop put bungs in my be-cool rad. I had the same over heating problem. What I found was the radiator tubes were expanded from possibly being over pressured when pressure testing. This restricted air flow. Replaced the rad and it ran cooler then it ever did. Check the radiator air flow. If he repaired it he pressure tested it. Does not take much pressure to ruin a good radiator. New employees make mistakes.
Click to expand...
You posted similar statement before about tubes breaking loose from fins. I am convinced that is what happened to my old original 273 rad. It was clean as a whistle and flowed lots of water yet would not cool
 
shouldn't there be about *30 diff between entering & exiting rad. ? shoot it with a thermometer ? double check gauge ?
 
SixPaksRule said:
Hello world, the car is not overheating, 240 would be over heating
200 is not hot...today's fuel dictates a 195 degree min operating temp, 60% water 40% antifreeze, a bottle of coolant conditioner, a high flow 195 degree t stat and a blocked manifold heat control crossover. Running colder than 195 causes excessive wear and the oil never gets a chance to keep clean. However please follow the old school thinking as nothing we have learned in 50 years of going very fast counts.
PS
Car came from ma mopar with a 192 degree t stat
Click to expand...


He’s not using a “modern” engine with knock sensors and EFI.

While pump fuel is formulated to be EFI friendly at the expense of carb fuel requirements.

I generally use compression ratio to determine what the coolant temperature should be.

Anything over 11:1 gets a 160. 10-10.9 is 180. Under 9:1 gets a 190.

Just because a “modern” car runs that hot doesn’t mean these cars should.
 
The change is concerning.

Do you use a shroud?

I would drain rad and flush block

Sediment, timing, air flow and use 13lb cap.

Then i would call rad company if no change.

If then not satisfied, id look at a higher flow water pump.

$0.02.

Pictures are always good.
 
I have had to send rads back, they do make mistakes, and also faulty parts.
If you have access to an infra red camera, here some pix Dana shot, showing plugged tubes, and hot water by-passing past the sides of the plugged finned area.
See if you can find a way to get a similar picture,
You may be able to find "cold tubes, or an area of cold, just shooting with a gun.
My Gut says the rad, if nothing else has changed .
Check all the pix

www.forabodiesonly.com

Radiator-Temperature

I am going to try to keep this short. I really don't want this to turn into a bickering match about - aluminum vs copper, thermostat vs no thermostat temperature or degree of thermostat to run have read way to much of it. 1972 Scamp 383, 727 trans w/remote cooler, 3.91 gears, electric fuel...
www.forabodiesonly.com www.forabodiesonly.com

Good luck
 
Newbomb Turk said:
He’s not using a “modern” engine with knock sensors and EFI.

While pump fuel is formulated to be EFI friendly at the expense of carb fuel requirements.

I generally use compression ratio to determine what the coolant temperature should be.

Anything over 11:1 gets a 160. 10-10.9 is 180. Under 9:1 gets a 190.

Just because a “modern” car runs that hot doesn’t mean these cars should.
Click to expand...

never heard that before , interesting !!
 
Just a thought....

I did not see that you mentioned the year and rad configuration.

If the in and out are on the drivers side pre 70 style, there is / should be a baffle in the top tank to divert flow to the pass side.

Maybe? When they did the repair they did not put it back in.

As for top hose lower hose temps...

Yes there should be a noticable difference. I measured mine on a long interstate drive and it was close to 50 deg difference.

The bigger the difference the more efficient your rad / cooling system is.
 
Oldmanmopar said:
I had a Rad shop put bungs in my be-cool rad. I had the same over heating problem. What I found was the radiator tubes were expanded from possibly being over pressured when pressure testing. This restricted air flow. Replaced the rad and it ran cooler then it ever did. Check the radiator air flow. If he repaired it he pressure tested it. Does not take much pressure to ruin a good radiator. New employees make mistakes.
Click to expand...
That’s a good idea, I’ll check that. The air draw through the radiator should increase with higher engine temps (after it’s warmed up) and higher RPM, correct?
 
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