440 overheating at idle

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RonsSwinger

RonsSwinger

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Looking for some ideas. I have a 71 Dart with a 440 conversion 60 thousand over bore, lumpy cam and 460-500hp. This past winter I replaced the entire cooling system (when I bought the car I thought the car ran hot on occasion). New Cold Case 2 row large tube rad, new water pump, high flow plastic fan, 180 thermostat, has a shroud, new aftermarket temp gauge and it is accurate. The car has no heater, never moves off 180 except at idle in heat (90 degrees+). I haven’t added Water Wetter, but plan to. Car has a vapour lock issue (I plan to insulate the fuel line to correct, it is too hot to touch). Having said all this the only potential issue is the fan spacing. The instructions for the fan calls for placing 3/4” from the rad and it is exactly 3/4”. Having said that the fan is almost completely inside the shroud and I have heard on several occasions that a fan should be 1/2 inside and 1/2 outside. Keep in mind I am mechanically minded and not a mechanic if you come up with some ideas that are extremely complicated. Penny for your thoughts. Ron D
 
You make no mention of "how hot" hot is. That said, over heating at idle is an air flow problem. Either not enough fan or it's not installed correctly. With no pictures, it's a guess at best.
 
RonsSwinger said:
Looking for some ideas. I have a 71 Dart with a 440 conversion 60 thousand over bore, lumpy cam and 460-500hp. This past winter I replaced the entire cooling system (when I bought the car I thought the car ran hot on occasion). New Cold Case 2 row large tube rad, new water pump, high flow plastic fan, 180 thermostat, has a shroud, new aftermarket temp gauge and it is accurate. The car has no heater, never moves off 180 except at idle in heat (90 degrees+). I haven’t added Water Wetter, but plan to. Car has a vapour lock issue (I plan to insulate the fuel line to correct, it is too hot to touch). Having said all this the only potential issue is the fan spacing. The instructions for the fan calls for placing 3/4” from the rad and it is exactly 3/4”. Having said that the fan is almost completely inside the shroud and I have heard on several occasions that a fan should be 1/2 inside and 1/2 outside. Keep in mind I am mechanically minded and not a mechanic if you come up with some ideas that are extremely complicated. Penny for your thoughts. Ron D
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From what I just read I don't see s "overheating" issue. What is the problem you are having?
 
Kept this high performance 440 running cool with an 18" solid mount fan and no shroud.

Screenshot_20220621-205007_Gallery.jpg


18" Fan

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No fan blade noise either. Soild mount big blade fans make lots of noise when you wind them up.

The new 18" fan pretty much runs silent, and still cools well.

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☆☆☆☆☆
 
Water pump should be 10-15% over driven, relative to the crank. See www.stewartcomponents.com for more info.

With a lumpy cam, you need a LOOOOOOOT of timing at idle, as much as 50*, but 25-40* is more common. This keeps the engine cooler because you are making it more efficient...& not work as hard. When the engine has to 'work', it produces more heat.

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I only run water wetter in straight water for the rust/corrosion inhibiting benefits. Used that stuff in a few vehicles and never saw any drop in temps. Definitely could try spacing the fan properly, no idea what the plastic fan looks like but I wouldn’t run one ever. I’d at minimum run a Derale or similar 6-blade aluminum rigid race fan. I’ve used their steel and aluminum blade versions and they move air especially at idle.

13'', 15'', 17'' or 18'' Standard Rotation Rigid Race Fan, Aluminum Blade

FEBBC518-88B5-48BF-BB0A-B2130BFE9870.jpeg
 
Fan not being half in half out might do it. Think how GM has shrouds that are 8-10" deep without fan close to radiator without issues. Also maybe timing as mentioned. JMO.
 
RustyRatRod said:
You make no mention of "how hot" hot is. That said, over heating at idle is an air flow problem. Either not enough fan or it's not installed correctly. With no pictures, it's a guess at best.
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At one point 220 degrees, and I think would slowly continue to climb furthe. Once the car gets under way it corrects back to the perimeters of the thermostat. The fan is inside the shroud with the edge of the fan level with the engine side of the shroud. I am leaning towards air flow as a start and plan to order a shorter fan spacer.. I like your saying. I consider myself an Honest man, not a smart man………. But I will advise people that I am one of the most resourceful people you will find….. I just wanted readers to know that I won’t let my confidence outway my competence.
 
RonsSwinger said:
At one point 220 degrees, and I think would slowly continue to climb furthe. Once the car gets under way it corrects back to the perimeters of the thermostat. The fan is inside the shroud with the edge of the fan level with the engine side of the shroud. I am leaning towards air flow as a start and plan to order a shorter fan spacer.. I like your saying. I consider myself an Honest man, not a smart man………. But I will advise people that I am one of the most resourceful people you will find….. I just wanted readers to know that I won’t let my confidence outway my competence.
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Well for what it's worth, I'll say it before someone else does.....220 ain't over heating. However, I'm in total agreement with you that it's too hot for "my" taste and I wouldn't like it either. I also agree with your assessment that it will reach the point of no return much quicker running that hot. "Somewhere" above 200 most all engines will get to the point where they just "give up" and start to get hotter and hotter. The hotter they run, the less cushion there is before they really over heat. That's why I like mine running as cool as possible. People will scoff saying you'll get extra engine wear running to cool, blah blah blah, but the simple fact is if you TUNE the engine TO cooler temperatures, it will be fine, run better and last longer than one running hotter. It's just an undeniable fact, that some people cannot understand. Forgive me for being too lazy to back read, but what are the dimensions on your radiator core? Width, height and thickness?
 
Oldmanmopar said:
What carburetor are you running. Could be it needs more fuel on the idle circuit.
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That could be a big contributor. You always think outside the box. That's a sign of possibly two things. Great experience or bein a geezer. Maybe a little of both? lol
 
Did you say you did have a fan shroud? Another thing is that the more horsepower you add the hotter the engine gets as a rule. Finally I would say some people are of the opinion that dense radiators like this don't allow as much airflow through. I've not experienced one side or the other but someone else can comment on that. I know on an big block A body you're scrounging for any cooling possible.
 
3/4" fan to radiator instruction is for a non shrouded radiator. The fan should be a third to half way into the shroud
 
Oldmanmopar said:
What carburetor are you running. Could be it needs more fuel on the idle circuit.
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Bewy said:
Water pump should be 10-15% over driven, relative to the crank. See www.stewartcomponents.com for more info.

With a lumpy cam, you need a LOOOOOOOT of timing at idle, as much as 50*, but 25-40* is more common. This keeps the engine cooler because you are making it more efficient...& not work as hard. When the engine has to 'work', it produces more heat.

View attachment 1716111473
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That makes sense and is on the check list. I had a guy set my valve lash and he said I didn’t have a timing pointer on the car. (I am on the hunt for one as we speak so I can check the timing). I bought the cooling system from a local performance shop and they recommended the fan because it pulls huge amounts of air (Flex-tite maybe).

48C154BC-3108-4A6E-B81D-45F852EEF518.jpeg


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36B9FA1F-6056-4E4F-9AEE-ABACFBAD96B1.jpeg
 
Vamisk said:
Did you say you did have a fan shroud? Another thing is that the more horsepower you add the hotter the engine gets as a rule. Finally I would say some people are of the opinion that dense radiators like this don't allow as much airflow through. I've not experienced one side or the other but someone else can comment on that. I know on an big block A body you're scrounging for any cooling possible.
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Yes has a shroud
 
69hemibeep said:
3/4" fan to radiator instruction is for a non shrouded radiator. The fan should be a third to half way into the shroud
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The new spacer is ordered this morning. That is the first time I had the measurements clarified. That is a piece of info I was looking for.
 
Oldmanmopar said:
What carburetor are you running. Could be it needs more fuel on the idle circuit.
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Carter 850. Idles great when you take the car up to temp. Drive it for a period of time 1/2 hr at 50mph etc and pull up to a stop and it idles rough (Vapour locking).
 
RonsSwinger said:
That makes sense and is on the check list. I had a guy set my valve lash and he said I didn’t have a timing pointer on the car. (I am on the hunt for one as we speak so I can check the timing). I bought the cooling system from a local performance shop and they recommended the fan because it pulls huge amounts of air (Flex-tite maybe).

View attachment 1716111595

View attachment 1716111596

View attachment 1716111597
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No question pulling the fan back out of the shroud will help. Also, get a real fan, because that "AIN'T" one, I don't care what your "SHOP" told you. That's a toy at best. If you want to retain a solid fan, get a Mopar factory fan, OR a Mopar factory clutch fan if you have the room. It appears that you may.
 
I honestly believe you have enough radiator in this instance, it's just the details need to be straightened out.
 
RustyRatRod said:
Well for what it's worth, I'll say it before someone else does.....220 ain't over heating. However, I'm in total agreement with you that it's too hot for "my" taste and I wouldn't like it either. I also agree with your assessment that it will reach the point of no return much quicker running that hot. "Somewhere" above 200 most all engines will get to the point where they just "give up" and start to get hotter and hotter. The hotter they run, the less cushion there is before they really over heat. That's why I like mine running as cool as possible. People will scoff saying you'll get extra engine wear running to cool, blah blah blah, but the simple fact is if you TUNE the engine TO cooler temperatures, it will be fine, run better and last longer than one running hotter. It's just an undeniable fact, that some people cannot understand. Forgive me for being too lazy to back read, but what are the dimensions on your radiator core? Width, height and thickness?
Click to expand...
I agree with what you say. I think the rad is 26” high-22” wide. I know the car will go to the point of no return. I have no concerns over the rad, did a lot of research and I am confident it is right for the job. Slight rise in temp I can live with, but I know it would continue to climb to the point of no return if you didn’t give it a run. That is not something I will live with. I did learn from the feedback (what I suspected) is the fan is too deep into the shroud and the fix is ordered today, that is my first step.
 
RonsSwinger said:
I agree with what you say. I think the rad is 26” high-22” wide. I know the car will go to the point of no return. I have no concerns over the rad, did a lot of research and I am confident it is right for the job. Slight rise in temp I can live with, but I know it would continue to climb to the point of no return if you didn’t give it a run. That is not something I will live with. I did learn from the feedback (what I suspected) is the fan is too deep into the shroud and the fix is ordered today, that is my first step.
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So......it runs hot when at idle. Does it cool off on the road?
 
Fan is too deep into the shroud, been there done that, same exact symptoms, position the fan approximately 1/2 way into the edge of the shroud.
 
RustyRatRod said:
No question pulling the fan back out of the shroud will help. Also, get a real fan, because that "AIN'T" one, I don't care what your "SHOP" told you. That's a toy at best. If you want to retain a solid fan, get a Mopar factory fan, OR a Mopar factory clutch fan if you have the room. It appears that you may.
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More confusion (back to, I am mechanically minded, not a mechanic). I have a clutch fan that I took off at the recommendation of 2 different mechanics. Having said that, will I change the fan at some point?, probably. Right now I know it moves a lot of air and I will keep it in place until I get the temp issue under control. At that point I will remove the fan and replace with a solid unit, right now I don’t believe the fan is the issue. I am leaning towards fan spacing, timing
 
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