When I got the 383 up and running, it was full of mud instead of water, that got flushed for about a year. And, the temps ran up to about 200F when pushed. In efforts to get it down, larger 3 row radiator copper, high flow pump and thermostat, and spring in the lower hose that was sucking a bit. So now, when romped in hot weather, it gets up to about 195.....not happy. So, my current hi flow pump from the summit is the aluminum impeller with radial spoke type fins. I also got one that uses the more original stamped steel type...not yet installed. So, I am wondering if anyone has tried the different types of hi flow pumps, with comments. I know I was getting pretty good flow before the hose spring, since it would suck down with revving in neutral. But, still wonder how to get this thing down to what I want to see, which is 180 worst case. I also reduced the glycol a bit from the 50-50 for more water, and added water wetter. I have seen previous thoughts on what is bad about 195, and I do not disagree....but. Any experience with the pump types appreciated.
Coolant temp again
- Thread starter 66furys
- Start date
Jakter
Well-Known Member
Coolant picks up heat in the engine and gives up heat in the radiator.
Why do you want to rush hot coolant through the radiator and back into the engine with the hi-flow nonsense?
Why do you want to rush hot coolant through the radiator and back into the engine with the hi-flow nonsense?
195 F is a good normal running temp for a 383 especially if you are working it
Cant argue with the points. Lower radiator is running about 140, but with higher flow it could screw up.....just pushing the envelope. I have never liked the higher temps....esp today as with the 210 thermostats, both gas and diesel. I dont give a crap about emissions, just engine health....and could be wrong on that as well??
sprice
Active Member
I purchased had a 440 in a Dart a couple years ago. Poorly maintained by previous owner. Black sludge and slimy (maybe stop-leak) type material in the rad. I flushed that for over and an hour (with car running). Still disgusted with the results. Could not see any signs of bubbling in the rad, water in the oil or smoke from the exhaust. Perhaps a professional chemical flush would have fixed this, however given the questionable condition, I pulled the engine and rebuilt it and the transmission with a new radiator. Not suggesting you need to do this, just pointing out a home flush may not be strong enough to be adequate.
70bigblockdodge
Old Man with a Hat
If your sucking the lower hose closed/shut you have a restriction in the radiator. Does coolant come out of the radiator if cap left off and revs to 2500 rpm.
"Hi-flow" pumps are touted (by their sellers) as a cure for overheating. More flow MUST be better?
Consider, there is an optimal window of flow rates where the coolant will successfully absorb heat from the engine, then move that heat to the radiator, and cycle repeat. Within the water routes, the water has to have minimum turbulence, too, as it passes through where it goes. Water moving too fast cannot always pickup enough heat or dissipate enough heat via the radiator.
One time, I needed a water pump for one of my cars. Went to an auto supply which offered a lifetime warranty on their water pumps. When I looked at the aftermarket casting, it was smooth inside and looked like it would flow great. When installed, the temp gauge ran one-needle-width hotter, consistently. Not to the middle the gauge, though. When that pump started leaking, I asked for a factory OEM casting pump. Temp went back down where it used to be. Which, to me, proves that a better flow might not always result in better cooling.
ONE thing which keeps the oil clean is operating temperature. Keeping the oil hot enough to cook-out all of the accumulated internal moisture from condensate which can form as the engine cools. If 180 degree F thermostats are good, then 195 degree F thermostats are better. In combination with a well-functioning pcv system.
When was the last time the freeze plugs were knocked out, replaced, and the rear of the cyl block's coolant passages washed out? The back of the block sits lower than the front, so that's where all of the accumulation starts first.
ATF starts to cook at about 270 degrees F and motor oil is not much hotter than that, as I recall. Even at 210 degrees F, plenty of margin. In normal use, atf and coolant temps will parallel each other, with engine oil taking about 20 miles or so of constant driving to get the oil fully up to temp. Or at least 10 miles/trip.
Take care,
CBODY67
Consider, there is an optimal window of flow rates where the coolant will successfully absorb heat from the engine, then move that heat to the radiator, and cycle repeat. Within the water routes, the water has to have minimum turbulence, too, as it passes through where it goes. Water moving too fast cannot always pickup enough heat or dissipate enough heat via the radiator.
One time, I needed a water pump for one of my cars. Went to an auto supply which offered a lifetime warranty on their water pumps. When I looked at the aftermarket casting, it was smooth inside and looked like it would flow great. When installed, the temp gauge ran one-needle-width hotter, consistently. Not to the middle the gauge, though. When that pump started leaking, I asked for a factory OEM casting pump. Temp went back down where it used to be. Which, to me, proves that a better flow might not always result in better cooling.
ONE thing which keeps the oil clean is operating temperature. Keeping the oil hot enough to cook-out all of the accumulated internal moisture from condensate which can form as the engine cools. If 180 degree F thermostats are good, then 195 degree F thermostats are better. In combination with a well-functioning pcv system.
When was the last time the freeze plugs were knocked out, replaced, and the rear of the cyl block's coolant passages washed out? The back of the block sits lower than the front, so that's where all of the accumulation starts first.
ATF starts to cook at about 270 degrees F and motor oil is not much hotter than that, as I recall. Even at 210 degrees F, plenty of margin. In normal use, atf and coolant temps will parallel each other, with engine oil taking about 20 miles or so of constant driving to get the oil fully up to temp. Or at least 10 miles/trip.
Take care,
CBODY67
On the flush, I got some evapo rust for a friend, and it comes out black, when it cleans out the rust. I have not had this in this engine yet, mainly because I pulled the block drains, had to drive out a rust plug inside, but flowed nicely after plug pushed out. Also, what I can see from the water pump opening is not bad. Finally, the block is transferring lots of heat to the water, which is Hot. So, I am trying to cool this hot water first, but again, do not disagree with anything said. I have a new radiator, and both acted same...not problemo with flow thru. The new larger one has lower temp at bottom, now running about 140F, so OK on heat transfer, I think. Finally, I have not pulled the plugs, and with an older engine, not a bad idea. And, thanks for all thoughts, am trying to figure out whether the owner or the engine is at fault here.
Drive it and enjoy it. It’s running just fine as far as temperature goes.
USSMOPAR
Active Member
From the factory the thermostat temp was 192F.
Wellllll, yes, but. I would like to have a bit of better cooling performance than it seems I do now. With my current 180 thermo, I was hoping it would now have the ability to keep it there, but it does not. The summit rad is made in mehico, but is large and three row copper, and appears well made. Not sure about capacity, that is in gallons, but looks good. So, was hoping to gain on ability to maintain, but have not. Do not disagree with all of the points here so far, but I am old and crotchety and not happy, yet. My meager research on aluminum radiators did not make me happy, so went with the larger copper. I may just have to regress to a friend back in the 60's with a fairlane 390 driving in traffic while coming home from Legune, had to turn on the heater full blast to help keep cool....might be my deal.
What temperature are you wanting your engine to operate at? You stated the bottom rad hose is at 140 F .
I would be very happy if it could maintain 180 when hot and in traffic or on the heavy romps.....second gear for a few miles on back roads pushing it. After my changes, we are at about 195 or a bit less. The engine is transferring the heat to the water, but the cooling part is not where I would like it. This is not a critical problem, as many have pointed out. I was just hoping to have developed a cooling system to stay ahead of anything the engine laid on it, and imo, it aint there. It sounds like I have not missed something, which is why I went down this road, and maybe, if important enough, I may have to look for an even wider radiator. I am up against the battery box, but there is some room on the passenger side. The fan and shround are giving good air flow...or so it seems. So, I think I should just have a beer for the time. thanks
A beer sounds great right now . I’m tapping out .
USSMOPAR
Active Member
Please OP - Humor those of us that disagree with your quest for a min operating temp less than 195F as the car does not benefit from the lower temp in any way shape or form. It's been proven beyond a reasonable doubt that 195F min operating is best for today's fuel along with blocking the cross over and opening the manifold heat control valve. And btw the cars from the factory came with a 192F thermostat back then, and for more trivia back in the day when the lower temps did help you could buy a 190F thermostat
so kindly humor us
so kindly humor us
IMHO, 195 is a good temperature.
You don't mention a couple things. What is the temperature for the thermostat and what kind of gauge are you using?
Sixpactogo
Well-Known Member
The factory did a ton of research on how much cooling is needed for our cars and they all worked just fine until we started messing with the system. People swap out the pulleys with serpentine systems that use smaller crank pulleys and larger water pump pulleys in the name of saving horsepower. Then wonder why their system is over heating when they are not moving the coolant fast enough. Others go the other way with a hi flow pump that moves the coolant too fast and it doesn't get a chance to cool. It sounds like yours is operating just as it should. How are you testing the temp when you say it is at 195? Are you going by the gauge or testing with an infra red digital? In post 13 you mentioned the fan and shroud are giving good flow. I thing you need to have that beer and call it good.
livininharrow
Senior Member
i think he's already had too many.
Knebel
Senior Member
My 360 runs 195 to 205. If I go 80mph plus the scoop adds cooling and it runs at 185
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