Trying to solve engine not cooling down

[dodj]

Three core aluminum rad with shroud. Edelbrock top end kit estimated to make about 475 hp. Replaced fan clutch with new one, no difference.
@MoparLeo  Getting on it and horsing around means anything that will put back in the seat. Thought you could have figured that out.

Well, to me this means you have the pump and the engine block left. If it were me I'd order up a 440 source aluminium pump and housing (I did it on my car just to lose some weight). Made a big difference for me. I don't have numbers but prior to the change the temp read exactly in the middle on the stock gauge and would vary up and down a bit depending on how 'spirited' you drove. For Leo, similar to 'getting on it'..lol JK. After the swap it reads on the quarter mark all the time. Never moves. I think, but don't know, that buying the 440 source pump and housing together gets a better match. Impeller depth in the housing is important and when you mix brands there will be variation. Just my opinion after reading various pump threads over the years.

[blown motor]

@dodj  Will that pump have higher capacity than the stock pump? I'm comparing the cooling pattern on this to my 340. With the 340 I can play all I want and the temp is good. With this 440 the temp goes up and won't come back down until I shut it off. Once it got hot enough I could hear it boiling when I shut it off, kind of scary.
@BFM_Cuda The fan is not dead centre in the shroud which leaves a gap on one side that is bigger than I'd like.  I wonder if I can slot the bolt holes in the shroud to center it better then get a slightly bigger fan.
I should mention this engine has about 3000 miles on the build. I did not build it so I'm just working with the car as I bought it.

[MoparLeo]

Never answered about coolant type/mix/percentage. Recovery system or just overflow. Radiator cap rating . These are all important questions if you are serious about diagnosing the problem.
If you can hear boiling in the system. it must be low on coolant/or air pocket in system. Pressure loss. And/or low on coolant % to distilled water.
https://www.dewitts.com/blogs/news/13852841-what-pressure-cap-rating-should-i-use
My back round is 40+ years of automotive service/repair. You need information to diagnose, especially since we are not there and just going by what you say.
The best you can expect are several educated guesses.
You need to do the testing, not just keep asking.
Diagnostics are a step by step process. Can take time and effort. And proper tools.
History... has this engine ever run cool or not since a recent change of a sort eg.. parts or adjustments. Everything is cause and effect.
If it was fine before, work back wards. engine driven fans are only efficient below 40 mph.
After that speed the fan does nil for cooling the radiator. Remember that the radiators job is to remove the heat from the coolant via heat "radiation" Like an electronic heat sink.
All cars with a/c have the condenser blocking radiator airflow.
You must solve the engines heart problem first before you go after the a/c. The a/c just points out the cars cooling system deficiencies.
It doesn't make the car run hot, it already did that and the fact that the temp does not go back down shows you your cooling system is inadequate for your engine/a/c combination.
Now when you get the engine hot, do you slow down to cool it off ? If so this is the opposite of what you need to do. Turn the a/c off and cruise around above 45 mph or get on the hi way or freeway To get more air flowing through the core and then it must cool down unless there is a blockage in the system.
Modern cars with larger engines generally run 2 electric fans. When you turn the a/c on most cars will have one of the fans immediately go on. This is because now you not only need to remove the heat from the cars cooling system but also the heat in the a/c condenser which is removing the heat from the refrigerant. They continue to work even when parked and shut off. You can hear cooling fans running in the parking lot in the summertime when every one is using their a/c. Since the engine is turned off the coolant is no longer flowing. This causes the engine to act as a heat sink and it gets hotter. The fans help keep the temp down in the radiator until the engine is started again. They run at a high speed that does not rely on engine rpms to work.
The cooling system was factory engineered for the stock engine and accessories. When ever you upgrade/modify the system, the rest of the system requires upgrading as well. Cause and effect again.
You have 2 separate cooling systems at work.
This is why when the radiators temperature rises, the transfer of heat from the radiator to the condenser makes the a/c less efficient and it will not blow as cool as it does when the engine is cool.
What degree thermostat do you have? A thermostat does not control temperature it is a thermo valve that opens and closes at a pre- determined temp. This just allows the coolant to now flow to the radiator. The coolant needs to be n the radiator long enough to have it's heat removed otherwise it will not cool down very much.
Putting in a 180° thermostat does not mean it will now run at that temp.
With todays fuels engines run hotter than 50 years ago when these cars were designed to run high octane/leaded fuel.
Contrary to what most people believe The higher the octane the slower the fuel burns.
That is why high octane tunes require more timing advance.
Regular fuel runs hotter than premium fuels do. That is the reason that running higher octane fuel in a car designed for regular show little return.
You may end up running hi-efficiency dual electric fans as part of your cooling system cure.
It probably needs to go to a cooling system specialist in your are to properly diagnose the situation and be able to do pressure testing and such.
And as far as the back in the seat comment, it was not a question of ignorance. Everything means something different everybody, follow ? Do you "get on it" for a few seconds ? Or on the freeway for a long time ? Or race the car. Anything you do in your driving style that is out of the "ordinary" places more load on the complete car. From the engine to the trans to the driveline , sus[pension, brake system etc.
I asked about whether it was an automatic and if so what stall of convertor is in it. This also affect engine temperature as well as transmission temp.

[blown motor]

Coolant is Prestone 50/50, the yellow/green stuff. There is an overflow bottle.
Getting on it pattern might look like this: coming out of town at 30 mph, hit the 50 sign and floor it up to 70 and let off, don't want a ticket. Come up behind a slow poke, pull out to pass and floor it up to 70 and let off. Get to intersection, turn off on to a secondary road and punch it up to 70 or 80. This covers about 5 miles. Each time I punch it the temp goes up and 5 miles of driving at 55-60 doesn't bring it back down at all. Now I'm done playing, don't want it going to 240 or 250. 

[dodj]

@dodj  Will that pump have higher capacity than the stock pump? I'm comparing the cooling pattern on this to my 340. With the 340 I can play all I want and the temp is good.

I can't give you flow numbers. I replaced the stock cast iron housing and pump with aluminium mainly because I was putting my 440 on a diet to lighten the front end. When I made the change the engine ran cooler - about a quarter sweep of the stock gauge. Mine sits at the first hash mark on the gauge and NEVER moves anymore. Idling at a light on a hot summer day used to make it move up slowly, now it doesn't. So evidence indicates better flow imo. I know, not very scientific, but that was my experience.
BTW, I run a 190* tstat.

[MoparLeo]

Change your overflow  to a coolant recovery system. this will eliminate air pockets in the system as this keeps the radiator always full. Go to twin thermal controlled electric fans, like modern cars install on the engine side as sucking fans.
These two things will help any car to keep the temps down. Something as simple as a malfunctioning radiator cap can cause overheating issue.
At the very least you should have a 16 lb. cap and test it. Even new caps can be bad.
This helps keep the boiling point at a higher temp. A bad cap will lower your boiling point and lead to boil overs.
Read the links that I list for more detailed info.
https://www.cruisingworld.com/understanding-coolant-recovery-bottles/
https://www.cleveland.com/automotive/plaindealer/2014/10/electric_fans_provide_plenty_of_benefits_for_restoration_and_hotrod_builds.html

[blown motor]

Sorry, I do have a recovery system.

[jimynick]

Murray, here's a wild thought, do you know if the block in your car was filled? To check you'd have to drain the coolant and carefully measure how much there was or how much it takes to refill it. It's possible that when buddy was having the hot engine built, that they put in some block filler and that would restrict the volume and it's cooling ability. As for the condenser, if they were a problem, pretty much every car on the road these days would be over-heating. Does the lwr rad hose have a spring in it? 

[Brads70]

Have you investigated the water pump as a possible issue? A/C used a different water pump from the factory?  Another thing is the pullies, if they are not right that will cause the pump to spin slower or faster ?
Look at post 191 and further....
http://www.dodgecharger.com/forum/index.php?topic=60599.175

[blown motor]

@jimynick  What is block filler and what's it's purpose?

Lots of things for me to investigate further. Thanks for the tips guys. Unfortunately it will be another three months before I can get the car out and test it some more.

[Filthy Filbert]

@jimynick  What is block filler and what's it's purpose?

Lots of things for me to investigate further. Thanks for the tips guys. Unfortunately it will be another three months before I can get the car out and test it some more.

Its basically concrete that they put into the water jackets to make the cylinder walls stronger and stop them from flexing. 

Pro--block is stronger and will hold more power
Con--reduced cooling capacity and is only ideal on race engines, but some guys have added oil coolers to make them streetable

[blown motor]

So I finally got back at this. I borrowed a system pressure tester from a friend. I'm working with three vehicles for comparison purposes, 74 Challenger, 79 Power Wagon and the Charger. Both the Challenger and the PW caps held pressure but the Charger cap didn't. It's the Big A cap in the pictures. I could build pressure in both the Challenger and the PW systems but not in the Charger. I do think that the issue there is the neck on the aluminum rad in the Charger. When I put the Big A cap on I can wiggle it round, the same if I put the Challenger cap on but the Challenger cap is tight on the Challenger. Same situation for the PW cap.
Also, both the Challenger and the Charger have 26" x 2 3/4" rads. The Challenger is three core steel and the Charger is two core aluminum. But the cores in the Charger rad are wider and it looks to me like it would have just as much core capacity. Or am I wrong?

[Fern]

Do you think that the lower radiator hose is collapsing when you get on it? That would cause it to restrict and overheat.
I also installed a high volume water pump, made a big difference for me.

[blown motor]

I checked today and there is not a spring. For what they cost I think I'll get one and put it in. Then we know it can't be that.
I'm guessing it's stock water pump, or else it's an aftermarket pump that's painted the same colour as the engine. Not sure how to tell.
How do ID the rad so I can figure out what the flow is suppose to be?

[Filthy Filbert]

Maybe I misunderstood.... Did you say one of the radiators is a STEEL core?! 

Check again.  From old school OEM to modern day OEM AND aftermarket, I have only ever seen radiators made from brass/copper or aluminum. 

As a metallurgist, I can tell you that steel is a terrible material to build a heat exchanger from.  Strength vs weight vs cost for a bridge or a building? Perfect.   As a light weight non-load-bearing heat exchanger? Probably the worst material to choose.