70bigblockdodge
Old Man with a Hat
You need a shroud.
Over heating Help
- Thread starter Cmaugel
- Start date
commando1
Old Man with a Hat
70bigblockdodge
Old Man with a Hat
I can cut that to fit.
A very simplified "cooling 101" ...
The temperature at which the coolant starts to boil is directly linked to the pressure in the system, the higher the pressure the hotter it can get before boiling over. Hence the 13 lb will let the rad run hotter before boiling than the 7 lb cap. BTW, my '70 440 requires a 16 lb cap, are you sure your 383 only wants a 13 lb?
Note the rad cap only controls the point of boil over, it does not have any effect on overall coolant temperature. The temp is a balance between the amount of heat generated by the engine and the ability of the circulation system and the radiator to dump heat. Basically the sum of heat in minus the heat out determines your coolant temperature. When your temp shoots up while sitting at idle, the reason is probably associated with slower circulation (low water pump rpm at idle), reduced heat dumping by the rad (low fan rpm and or clogged coolant passages).
If, in perfect world, your cooling system is capable of dumping heat faster than the engine can produce it, a thermostat is used to regulate the coolant flow. If the engine design temperature is say 180F then the thermostat will close below that temp to heat up the engine. When the temperature rises above 180F the thermostat opens allowing coolant to pass thru the rad and bring the temperature down. Unless your thermostat is stuck closed, which its not because you don't overheat on the road, your overheat at idle is not thermostat.
So your problem is not rad cap or thermostat.
What's left?
- idle set too low??
- waterpump blades corroded - replace pump
- crud in the block passages - power flush
- crud in the rad - power flush
Water pumps are not all equal. Silly as it sounds thed old Mopar pumps are much more efficient than the new fancy looking products.
Anyhow, end of cooling 101!
If I were you, I'd flush the heck out your system and replaced the anti-freeze.
The temperature at which the coolant starts to boil is directly linked to the pressure in the system, the higher the pressure the hotter it can get before boiling over. Hence the 13 lb will let the rad run hotter before boiling than the 7 lb cap. BTW, my '70 440 requires a 16 lb cap, are you sure your 383 only wants a 13 lb?
Note the rad cap only controls the point of boil over, it does not have any effect on overall coolant temperature. The temp is a balance between the amount of heat generated by the engine and the ability of the circulation system and the radiator to dump heat. Basically the sum of heat in minus the heat out determines your coolant temperature. When your temp shoots up while sitting at idle, the reason is probably associated with slower circulation (low water pump rpm at idle), reduced heat dumping by the rad (low fan rpm and or clogged coolant passages).
If, in perfect world, your cooling system is capable of dumping heat faster than the engine can produce it, a thermostat is used to regulate the coolant flow. If the engine design temperature is say 180F then the thermostat will close below that temp to heat up the engine. When the temperature rises above 180F the thermostat opens allowing coolant to pass thru the rad and bring the temperature down. Unless your thermostat is stuck closed, which its not because you don't overheat on the road, your overheat at idle is not thermostat.
So your problem is not rad cap or thermostat.
What's left?
- idle set too low??
- waterpump blades corroded - replace pump
- crud in the block passages - power flush
- crud in the rad - power flush
Water pumps are not all equal. Silly as it sounds thed old Mopar pumps are much more efficient than the new fancy looking products.
Anyhow, end of cooling 101!
If I were you, I'd flush the heck out your system and replaced the anti-freeze.
Hopefully I will not need to resort to religious artifacts or miracles just yet. Here's another mess of questions for you guys:
Is there a particular radiator any of you would reccomend? If you have a link even better.
Is there a shroud that would fit without much trouble that is common to mopars, like a Fury, Satellite, etc.? Or an aftermarket shroud? I don't know much about which parts are common with different mopar models.
Any pictures of your set-ups, either factory or custom, that works well for you?
Any thoughts on an improved fan? Maybe a bigger flex-fan?
I saw in the receipts the car came with that they'd bought a fan clutch, but must have given up on that. I am thinking that they'd assumed their chosen radiator would have been fine with the fan clutch installed. Once again, thank you all for your input and info. I am really appreciating the knowledge available here! Hopefully you guys don't mind my millions of questions, (which never end).
Is there a particular radiator any of you would reccomend? If you have a link even better.
Is there a shroud that would fit without much trouble that is common to mopars, like a Fury, Satellite, etc.? Or an aftermarket shroud? I don't know much about which parts are common with different mopar models.
Any pictures of your set-ups, either factory or custom, that works well for you?
Any thoughts on an improved fan? Maybe a bigger flex-fan?
I saw in the receipts the car came with that they'd bought a fan clutch, but must have given up on that. I am thinking that they'd assumed their chosen radiator would have been fine with the fan clutch installed. Once again, thank you all for your input and info. I am really appreciating the knowledge available here! Hopefully you guys don't mind my millions of questions, (which never end).
Thanks Bill. According to everything I can find, the non-A/C factory cap for the '66 Fury with 383 is 13lbs and the A/C equipped is 16lbs.
I agree a thorough flush is needed, regardless of everything else. I am interested to see what difference the flush alone may make. I do know the idle is good and not too low as well. I'm hoping the water pump will be alright, but we'll see. Thanks again for your info!
I agree a thorough flush is needed, regardless of everything else. I am interested to see what difference the flush alone may make. I do know the idle is good and not too low as well. I'm hoping the water pump will be alright, but we'll see. Thanks again for your info!
70bigblockdodge
Old Man with a Hat
If it is staying cool on the highway the radiator is okay. Getting hot sitting still points toward airflow, a shroud for a non stock radiator a lot of work or lots of looking or you could mount a thermostatic controlled pusher electric fan to the front of the radiator. It kicks on at a adjusted temp measured by a probe you stick in the fins somewhere near the top/ water inlet it will cycle on and help the engine driven fan at idle/sitting still, traffic, move more air and not do anything when you are on the highway. If your sheet metal skills are up to it you could make a shroud out of aluminum.
I don't agree with magic solutions like shrouds and/or fancy fans.
My factory 440, without air, was born with a dinky 22" rad, a steel 7 blade fan, a 16 lb rad cap and a 190F thermostat. For the first 90,000 miles of it's life I never had any heat problems. At 90K the car got parked for 30 years or so.
During the restoration the engine block was boiled, the rad was re-cored and the water pump was replaced with an OEM refurb. My car runs great on the highway, temp about 190F. Dicking around in traffic, not so good. It doesn't take long to hit 220F and start puking coolant. I'm thinking a re-corded rad is not as good as the factory rad. I'm also thinking the OEM water pump doesn't flow enough volume at low rpm. I am currently reading
http://www.dodgecharger.com/forum/index.php/topic,60599.0.html
My factory 440, without air, was born with a dinky 22" rad, a steel 7 blade fan, a 16 lb rad cap and a 190F thermostat. For the first 90,000 miles of it's life I never had any heat problems. At 90K the car got parked for 30 years or so.
During the restoration the engine block was boiled, the rad was re-cored and the water pump was replaced with an OEM refurb. My car runs great on the highway, temp about 190F. Dicking around in traffic, not so good. It doesn't take long to hit 220F and start puking coolant. I'm thinking a re-corded rad is not as good as the factory rad. I'm also thinking the OEM water pump doesn't flow enough volume at low rpm. I am currently reading
http://www.dodgecharger.com/forum/index.php/topic,60599.0.html
1966newport
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my cars are both 440s with 22 inch radiators, never go over 205 in upper 90 temps
70bigblockdodge
Old Man with a Hat
Wow my car is magic from the factory it has a shroud. It also does not overheat. His problem is clearly airflow at low or no speed , the fact that the thermostat has to take over and regulate the temp at highway speed shows that his cooling system is working properly when there is plenty of airflow and the engine is even making more heat. Its just that simple needs more air.
The key to good cooling is having a radiator core with very high fin density - the factory cores were pretty good in that area. Most aftermarket cores are poor in that regard. You will save yourself much time, frustration and money over the long haul to invest in a high fin density, high efficiency core. Craig makes them and so do some other companies. But a 3 or 4 row core with high fin density will run over $400 for a 26" radiator. But it will be worth it. The only other approach that helps significantly, particularly in traffic, is to add an electric fan or just convert to non-factory looking aluminum cores. Shrouds always help but the improvement will not be great if the cores are poor to begin with.
Steve
Steve
Couple years ago a very interesting study was done using proper flow measuring equipment to compare a bunch of different BB water pumps.
http://www.dodgecharger.com/forum/index.php?topic=60599.180
Scan about half way down to reply #191.
I think a lot of our engines over heat simply because the pump flow rate at low rpm is too low to cool the engine. Take particular note of the "factory" pump, it appears to smoke them all.
http://www.dodgecharger.com/forum/index.php?topic=60599.180
Scan about half way down to reply #191.
I think a lot of our engines over heat simply because the pump flow rate at low rpm is too low to cool the engine. Take particular note of the "factory" pump, it appears to smoke them all.
70bigblockdodge
Old Man with a Hat
I agree Steve fin counts are key I was just trying to give him some fixes with what he has. I am going to guess that his fan is at least 3 inches back from the core and is not pulling enough air, his radiator seems to work okay, that's why I brought up a pusher fan because no stock shroud is going to work with that aftermarket radiator.
65sporty
Old Man with a Hat
Did you say what fan you are using? As was already said you need a shroud
I'm dealing with exact the same problem! 1970 Sport Fury, 383 engine, aftermarket 22 inch rad, no shroud.
going to install a pusher fan in front of the rad, see how that works out, already replaced the thermostat, cooling while driving is ok now.
keep you posted!
going to install a pusher fan in front of the rad, see how that works out, already replaced the thermostat, cooling while driving is ok now.
keep you posted!
ECPJT
New Member
If your radiator is Aluminum, then a shroud is absolutely vital, either with Mech. or Elec. Fans!
bulldogchesty
Senior Member
Evapo-Rust has a block cleaner that looks very promising. I may give it a try myself.
commando1
Old Man with a Hat
My method for a complete and thorough flush.
1. Remove thermostat and reinstall the housing.
2. Disconnect upper radiator hose from radiator and direct the flow coming out of the block towards ground.
3. Set car heater to MAX.
4. Make sure radiator is empty.
5. Add chemicals of mass destruction (your choice) to radiator.
6. Insert garden hose into radiator.
7. Start engine and wedge something in carburetor linkage so that it runs at a high idle.
8. Turn on garden hose so flow of water matches flow of water coning out of upper radiator hose.
9. Run, run, run, until water coming out of upper hose looks clean enough to drink.
10. Add small amt. of Tide laundry detergent to radiator.
11. Continue flushing process until soap coming out of hose is gone and water is crystal clear again.
Stop engine.
12. Install new thermostat (180° minimum) and gasket and upper hose.
13. Drain radiator again andd A/F to radiator until full.
14. Restart engine and bring up to high idle again.
15. Purge system of air COMPLETELY, and add additional A/F as nec.
16. Dispose of dead animals who you indvertantly let drink the old antifreeze flowing down driveway.
Wash down driveway to remove evidence.
To divert the coolant coming out the upper hose away from you and the car, I found that a hose from a Shop Vac is the same size.
1. Remove thermostat and reinstall the housing.
2. Disconnect upper radiator hose from radiator and direct the flow coming out of the block towards ground.
3. Set car heater to MAX.
4. Make sure radiator is empty.
5. Add chemicals of mass destruction (your choice) to radiator.
6. Insert garden hose into radiator.
7. Start engine and wedge something in carburetor linkage so that it runs at a high idle.
8. Turn on garden hose so flow of water matches flow of water coning out of upper radiator hose.
9. Run, run, run, until water coming out of upper hose looks clean enough to drink.
10. Add small amt. of Tide laundry detergent to radiator.
11. Continue flushing process until soap coming out of hose is gone and water is crystal clear again.
Stop engine.
12. Install new thermostat (180° minimum) and gasket and upper hose.
13. Drain radiator again andd A/F to radiator until full.
14. Restart engine and bring up to high idle again.
15. Purge system of air COMPLETELY, and add additional A/F as nec.
16. Dispose of dead animals who you indvertantly let drink the old antifreeze flowing down driveway.
Wash down driveway to remove evidence.
To divert the coolant coming out the upper hose away from you and the car, I found that a hose from a Shop Vac is the same size.
Last edited:
Tink
Well-Known Member
I had a very similar problem on a completely different vehicle. It ran hot when in a "drive-thru" line. It was all factory stock. After a system flush rid the system of a lot of rusty coolant and fresh coolant added, the problem remained. New thermostat, radiator cap installed at flush. I decided to replace the water pump. I was amazed when I looked at the old pump. Its impeller was completely dissolved. Nothing but the backing plate and shaft remained. Factory pump with 100k on the clock. It has run as new since.
The cooling system on a vehicle is a "closed" system. The radiator cap controls the maximum pressure that system will sustain. The higher the system pressure, the higher the fluid temperature can get to before turning to vapor. Vapor is bad in a closed cooling system. You should vent the system after repairs by running the vehicle up to temperature (thermostat opening) with the radiator cap off until the fluid level is stable in the radiator.
The cooling system on a vehicle is a "closed" system. The radiator cap controls the maximum pressure that system will sustain. The higher the system pressure, the higher the fluid temperature can get to before turning to vapor. Vapor is bad in a closed cooling system. You should vent the system after repairs by running the vehicle up to temperature (thermostat opening) with the radiator cap off until the fluid level is stable in the radiator.
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