slantsixdan
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Many, many years ago I had one (1), removed from a '64 Dart wagon with Mopar underdash A/C. I know I didn't sell it, and I know I don't still have it. I don't recall what happened to it.
Only one I ever had.
Cooling Issue - 1964 Dart GT - 273 with automatic and A/C
- Thread starter Dart5150
- Start date
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Only one I ever had.
slantsixdan
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So does 40 to 60 per cent coolant mixed with the water.
MILO
Well-Known Member
I bought a 64 dart with overheating problem and found the lower radiator hose had a plastic plug inside causing restricted flow
harrisonm
Well-Known Member
Well, @RustyRatRod, here we go again. Somebody partially blocked the flow in the radiator hose to "help" an overheating problem. Because we all know that the water has to move slowly through the radiator, right?
It seems like we were just discussing this a few weeks ago.
JDMopar
Well-Known Member
The lower radiator hose should have a spring inside of it. Factory installed them to keep the water pump from sucking the hose flat and slowing or stopping the flow.
slantsixdan
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'Collapsed rad hose' is largely a myth. The upper hose would never collapse, and the only reason why the lower hose could collapse is if there is severe clogging or restriction in the radiator or thermostat—and the hose would then un-collapse once the system heats up and builds pressure.
I don't claim it can't happen—only that it is exceedingly rare and has one specific cause. Think it over: that bottom hose runs from the radiator outlet to the water pump inlet. The only way for there to be negative pressure in that hose is for there to be extreme restriction upstream of that hose so the water pump pulls a vacuum, and the hose would have to be weak/soft, and there'd have to be no/low pressure in the system as a whole.
That spring that used to come in some rad hoses was meant to keep the hose from kinking if overbent. Cut the hose to length (as required) and install it properly, and have good engine mounts, and there won't be any kinky stuff happening.
Rapid Robert
Well-Known Member
needs more air and or water flow. if your crank pulley is the largest available get a smaller WP pulley. Post how things turn out. RR EDIT utube has some good vids ("beer budget" iirc) on making the mopar pump more efficient
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So it's not overheating. You really don't know how hot it really is getting looking at the factory gauge. I have said this so many times I don't even type it out, just cut and paste. "At 220° your engine is not overheating. Is it boiling over? Water boils at 212°. A 50/50 mix of antifreeze boils at 223° and for every pound of cooling system pressure you add 3°. With antifreeze and a 15# cap, your coolant won't boil until 268°. As mentioned, air flow is the key."
Swinger 340
Well-Known Member
Sorry Slant six, it's not a myth, that is why I mentioned it. It has happened to me years ago. Not only did the hose suck in, but I had to pull the water pump to take the spring out of it. It is true as you say that a restriction ahead of the hose could also collapse the hose, if the spring or hose became weak. My point being, over heating can be caused by many things, as many here mentioned. I just added another possibility.
mario03srt
Well-Known Member
Hi,
I would guess that you have an air pocket in the system.
Take a 2 liter bottle. Cut off the bottom. Wrap the screw opening with some tape. Remove the rad cap. Screw in the 2 liter bottle. Fill it up with some coolant. Fire the car and let it operate. Once the bubbles stop and it looks like coolant was used and your satisfied stop the motor. Carefully, remove the 2 liter and remaining contents. They sell kits to do this, but this is cheaper.
FYI,
Marion
I would guess that you have an air pocket in the system.
Take a 2 liter bottle. Cut off the bottom. Wrap the screw opening with some tape. Remove the rad cap. Screw in the 2 liter bottle. Fill it up with some coolant. Fire the car and let it operate. Once the bubbles stop and it looks like coolant was used and your satisfied stop the motor. Carefully, remove the 2 liter and remaining contents. They sell kits to do this, but this is cheaper.
FYI,
Marion
slantsixdan
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Probably not. That happens in vehicles where the top inlet of the radiator is not the highest point in the cooling system, but it is by what might as well be a mile in a '64 Dart (or any other old Mopar, or most any old car, for that matter), so not possible for air pockets to form. That's a newer-cars thing.
But even if it were an air pocket, it would cause the opposite of the OP's problem. Air surrounding the coolant temp sender will cause the gauge to read lower than it would if bathed in liquid/coolant. The engine would be showing symptoms of overheating with the gauge not near H.
Two things:
1. Get an aftermarket mechanical temperature gauge. Can't tell s$&t from the factory gauge.
2. Someone mentioned this early on, but haven't heard anything since - knock the freeze plugs out and flush out the block.
Get those two things squared away and if you still have a problem, then you can think about bigger radiators, different fan, fan shroud, etc., etc.
For what it's worth the 340 in my 65 Barracuda never overheats, or even runs over 200 degrees here in Tallahassee, with factory radiator three row recore, non-thermostatic clutch fan and no fan shroud.
1. Get an aftermarket mechanical temperature gauge. Can't tell s$&t from the factory gauge.
2. Someone mentioned this early on, but haven't heard anything since - knock the freeze plugs out and flush out the block.
Get those two things squared away and if you still have a problem, then you can think about bigger radiators, different fan, fan shroud, etc., etc.
For what it's worth the 340 in my 65 Barracuda never overheats, or even runs over 200 degrees here in Tallahassee, with factory radiator three row recore, non-thermostatic clutch fan and no fan shroud.
mario03srt
Well-Known Member
I just purged mine when I bought it back in November. Previous owner was chasing other solutions.
Dave_J
Well-Known Member
My comment above about checking the Valve lash is one thing I'd check as this is a 1965 273 with a solid lifter cam.
Yes you can put a Hyd cam in one with the 318's rocker arms but most never did.
If the lash is too tight it will run HOT.
Yes you can put a Hyd cam in one with the 318's rocker arms but most never did.
If the lash is too tight it will run HOT.
Dart5150
Well-Known Member
Update -
The lower radiator hose was the issue, as it was collapsing as noted by some on this thread. Replaced it with a new one, as well as the thermostat that failed in the open position, and it now cools perfectly. After a half hour of stationary run time in the sun, I can't get it to get over 202 degrees at the temp sender location on the intake manifold, as verified by an infrared thermometer. This is using the 3,000 cfm electric fan with sensor and relay.
Since I need to drain the coolant again to install a spring in the lower hose, I'll likely try reinstalling the mechanical 7-blade fan with a taller spacer that'll get it closer to the radiator, and see how well it cools without the electric fan.
Many thanks to all for your thoughts and help!
The lower radiator hose was the issue, as it was collapsing as noted by some on this thread. Replaced it with a new one, as well as the thermostat that failed in the open position, and it now cools perfectly. After a half hour of stationary run time in the sun, I can't get it to get over 202 degrees at the temp sender location on the intake manifold, as verified by an infrared thermometer. This is using the 3,000 cfm electric fan with sensor and relay.
Since I need to drain the coolant again to install a spring in the lower hose, I'll likely try reinstalling the mechanical 7-blade fan with a taller spacer that'll get it closer to the radiator, and see how well it cools without the electric fan.
Many thanks to all for your thoughts and help!
Thanks for the update. Might help someone else down the road.
Does the new hose have a spring. It should have. If not, you can make one from welding wire, fencing wire or the humble wire coat hanger. Wrap wire around something a bit smaller in OD then the hose ID.
Swinger 340
Well-Known Member
I would use a stainless wire and be sure it is a tight fix or it can end up in your water pump. I have gone to salvage yards in the past and pulled the wire out of an older vehicle and reused it in mine.
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