Anyone have a Big Block that DOES NOT OVERHEAT at Idle in hot weather?

[Banana]

- Stock 440-4, with 440-6 cam and pistons
- Recored Stock Radiator
- New Fan Clutch from Tonys
- Timing around 12 degrees
- 50/50 Prestone
- Stock exhaust

Car is moving temp is OK (around 1/3 up the temp gauge). Sitting at idle just can't keep it from creeping up and overheating.

Anyone with fully stock 440 that stays cool? What items am I missing?

Thanks

[xx88man]

Do you have a fan shroud on there?   

[Banana]

Yes.........it was a repro, and initially it was warped causing big gaps between the radiator and shroud............I then reformed it using weights and heat, and was able to close 80% of the gap......probably very similar to stock gap now................it did help cool further, but still not enough

Also, the fan is stock with no spacers......fan is about 50% into the shroud as it should be

Just wondering if anyone with a Big Block is able to sit in traffic in the summer using a stock radiator, and not have to go with an aluminum radiator or electric fan.

[70vert]

Mine is not stock, and it does get hotter at a stop light (while in gear) but it does not overheat.
1970 Challenger
440 Auto - mild build with Comp cam, Mopar M1 intake, headers
OE 22" radiator with shroud
Viscous fan, aluminum water pump housing, Prestone 50/50

I'm in Houston so not surprised it heats up, but no issues boiling over and if I flip it to neutral at a stop it cools right down. I have looked at radiators (just for ways to spend money and improve cooling) and found this to be the best choice - https://speedcooling.com/22-Mopar-BIG-BLOCK-HD-Aluminum-Radiator.html

[bc3j]

Yes, no heating issues w/ a N code stock 383, stock exhaust, 195* thermostat, 50/50 prestone, 26" stock radiator, factory shroud w/factory 5 blade fan with clutch, AC car not currently installed but w/ AC water pump. Timing set more or less by hearing than a light. Advanced until idle increased then started to run rough and backed it off a little. An old time mechanic told me that method many, many years (decades) ago. He said every engine has its own timing setting. Works for me as the engine starts and runs well hot or cold. Been in 95* days idling without any rise from the temperature gauge. Curb idle is 1000 and 750-800 in gear (auto).
Edit: Rechecked idle and it's at 700 in gear. Curb idle 900. No problems. 

[ek3]

 what water pump is in it? if its pulling plenty of air , it may not be moving the water fast enough at idol speeds....

[JH27N0B]

I've never had overheating issues with either of my big block Challengers, a 70 383, and a 71 440-6, both stock with 26" radiators.

[Banana]

Thanks Guys, I'll keep checking all the areas you mentioned

[Todd489]

I have a 383/489 stroker, little under 600 HP, I'm  in ct and even on the hottest day it does not go above 200 sitting in traffic for a while, I have a 26-in radiator with a four-row core in it, a high flow thermostat 180°, and a milodon hi flow water pump. And factory fan shroud.

[Racer57]

Is your radiator a 26"  4 core ?  My 383 had problems with the 3 core that was in it. It was old and probably blocked in places so I had a shop use the existing top and bottom and put a 4 core in. No problems now.

[dodj]

My 440 used to warm up with extended idling. When I replaced the water pump and housing I learned that the depth of the pump within the housing is important.  So use the thinest gasket you can without interference. I installed a 440 source housing and pump.  I can leave it idling all day now and it will not move up over 1/3 of the gauge sweep. And I have no shroud.

[Banana]

I had my original 26" restored at Glen-ray with the upgraded core. Looks fantastic, and I have to assume that with the rebuild, the radiator would cool a bit better than factory.  So, I haven't considered that the radiator may be the issue, but maybe can't rule anything out.

But any feedback on re-built stock radiators that Have Not performed well would be appreciated.

[jt4406]

Use the paper roll from a empty roll of paper towels and see if you can stop the fan while it is idling. If you can, replace the fan clutch.  Just my .02

[PLY474]

Thermocure works well to remove rust from inside the block.  https://www.amazon.com/Thermocure-Coolant-Remover-Removes-Cooling/dp/B00R74I5UY/ref=sr_1_2?crid=2GRH2WI9BN168&dchild=1&keywords=thermocure&qid=1626529674&sprefix=thermocu%2Caps%2C286&sr=8-2

[Banana]

Adding some pix. I read that the fan must be 30 to 50% into the shroud to be effective. Looks like mine may be borderline 30%, or even less. Using all stock components.

Please confirm the 30 to 50% overlap standard, and if you guys see any parts not looking correct. Maybe the report shroud is a bit short? Pulley?