440 OVERHEATS

[Pops1973]

My 440/512 motor home engine gets hot as high as 220+. It never stops climbing. Trick flow 240 heads, four core aluminum radiator, electric 35gpm water pump, 1 16" shrouded electric fan pulling, 2 10" fans on a/c condenser one pushing, one pulling. The a/c just makes it get hotter faster. Any Ideas?

 

[Xcudame]

Get a radiator that's the same thickness but two row instead of four will make huge difference. For a few degrees of improvement, water wetter works.

Red Line Water Wetter Super Coolant 12oz

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[Seattle 70 RT]

My 440/512 motor home engine gets hot as high as 220+. It never stops climbing. Trick flow 240 heads, four core aluminum radiator, electric 35gpm water pump, 1 16" shrouded electric fan pulling, 2 10" fans on a/c condenser one pushing, one pulling. The a/c just makes it get hotter faster. Any Ideas?

Pops, check if the fan is turning. I recently had an overheating problem with my 70 Chally with a similar radiator and electric fan. The fan relay broke and rather than spend the time and effort tracking sown the problem I replaced the electric fan with a mechanical fan, problem solved.

 

[Xcudame]

I must add, although electric fans rob less horse power and look cool, the factory mechanical clutch fan cools very well! Small block and big block Mopar cop cars would idle for hours and never overheat even in hot places.

 

[Chryco Psycho]

Start with tuning Timing should be 16* at idle 3-6-38 full advance . Retarded timing creates heat .
Carb rich or lean ? Air bleeds dialed in ?
Correct heat range plugs .
Electric fans often block more air than they flow especially when moving, Factory clutch fans with a shroud move a lot more air & don;t block air at speed

 

[Ricks72Chlgr440]

My 440/512 motor home engine gets hot as high as 220+. It never stops climbing. Trick flow 240 heads, four core aluminum radiator, electric 35gpm water pump, 1 16" shrouded electric fan pulling, 2 10" fans on a/c condenser one pushing, one pulling. The a/c just makes it get hotter faster. Any Ideas?

It overheats at idle sitting in traffic or while driving down the road?

 

[DetMatt1]

My 440/512 motor home engine gets hot as high as 220+. It never stops climbing. Trick flow 240 heads, four core aluminum radiator, electric 35gpm water pump, 1 16" shrouded electric fan pulling, 2 10" fans on a/c condenser one pushing, one pulling. The a/c just makes it get hotter faster. Any Ideas?

Has this always been the case or did it come out of nowhere?
My guess is that you are moving the water too fast and there’s not enough air flow.

 

[Pops1973]

Thanks to all I will try a fatter 2-core radiator. water wetter sounds good also.

It overheats at idle sitting in traffic or while driving down the road?

while driving at around 2500 and up when idle cools slightly never below 200degrees

 

[Pops1973]

Has this always been the case or did it come out of nowhere?
My guess is that you are moving the water too fast and there’s not enough air flow.

Right from the start, I can't run the interstate at all.

 

[Pops1973]

Start with tuning Timing should be 16* at idle 3-6-38 full advance . Retarded timing creates heat .
Carb rich or lean ? Air bleeds dialed in ?
Correct heat range plugs .
Electric fans often block more air than they flow especially when moving, Factory clutch fans with a shroud move a lot more air & don;t block air at speed

I will check the timing, AFR 13, and plugs are Champion RC12YC.

 

[DetMatt1]

In my opinion you’ve introduced too much fancy aftermarket junk to your cooling system. Chrysler already paid some of the best engineers to make a bulletproof cooling system.

 

[Xcudame]

Back when we had our 70 Challenger stock car (roundy round racing), we just used used the factory fan shroud, water pump and clutch fan (yes!) on the 360. The Chevy guys would come off the track and hose their radiators down (engine running). I remember we'd come off and I'd yell to the pit crew, "We're running 180 degrees on water temperature!" loud enough the Chevy guys could hear!

 

[Pops1973]

In my opinion you’ve introduced too much fancy aftermarket junk to your cooling system. Chrysler already paid some of the best engineers to make a bulletproof cooling system.

Thanks for your opinion. I'm starting to agree with you. I'm looking for a new setup to drive everything.

 

[Juan Veldez]

Also, no more than 50% anti-freeze. I'd say an aluminum radiator, 2 or 4 core, is better than stock (IMO). Aluminum dissipates heat faster than steel. Don't start with replacing the radiator or fan set up. Start with easy, inexpensive possible fixes first (in no particular order). 1- correct water to anti-freeze ratio 2- confirm fans start turning at desired temp 3- add Water Wetter 4- check thermostat is working/opening at desired temp 5- correct timing and fuel/air mixture 6- confirm water pump works but letting it get hot with the radiator cap off and looking into the radiator for flow 7- confirm system is sealed, no leaks. If none of these work, than change the fan/shroud set up. Let us know what solves the problem - good luck.

 

[Old Mopar]

Also, no more than 50% anti-freeze. I'd say an aluminum radiator, 2 or 4 core, is better than stock (IMO). Aluminum dissipates heat faster than steel. Don't start with replacing the radiator or fan set up. Start with easy, inexpensive possible fixes first (in no particular order). 1- correct water to anti-freeze ratio 2- confirm fans start turning at desired temp 3- add Water Wetter 4- check thermostat is working/opening at desired temp 5- correct timing and fuel/air mixture 6- confirm water pump works but letting it get hot with the radiator cap off and looking into the radiator for flow 7- confirm system is sealed, no leaks. If none of these work, than change the fan/shroud set up. Let us know what solves the problem - good luck.

good info above! 60% water 40% antifreeze, coolant additive. There is a flow/delta issue with the system. Delta is the difference in water temps in the rad and out. Your thermostat choice does affects overall operating temp. Yes indeed.
good luck with the aftermarket set up

 

[Ctriton20]

My build is close to yours and I had the same problem. If you install this Ford electric fan RNB-620-104 from Summit you will be good. This fan setup moves 2500-3000 cfm of air. I took me 3 months to work out this issue. TTI Ceremic coated headers help too. The problem with the stock fans is that they were not designed to cool engines with 600 plus horsepower. I installed a new 26" Radiator, 180 degree electric temperature sender, 180 degree thermostat. This is a two speed fan. I run it on the high speed. Now I can drive me 400/512 stroker anywhere and it never goes above 195 degrees. You may have to upgrade your alternator. This overheating issue had me pulling my hair out! None of the other quick fixes worked for me. If you need me to share the setup just let me know.

 

[Chryco Psycho]

If you choose an Alum rad make sure you isolate it with rubber mounts , alum cannot out up with flexing like brass will .