Radiator question

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williaml

williaml

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Does anyone know what the GPM rate is on a standard radiator is on a 1965 Dodge Dart with a slant 6, 225 is? Trying to determine if the rad needs re-coring or is something else going on.
 
It may be helpful to know what problem you are attempting to correct and the exact symptoms.

I would test the radiator in place with a non-contact infrared temperature gun. You want to see a 20 to 30 degree temperature drop from the inlet to the outlet. You can also use the same gun to check for cold spots in the radiator core that indicate a blockage.
 
Rustedwrench said:
It may be helpful to know what problem you are attempting to correct and the exact symptoms.

I would test the radiator in place with a non-contact infrared temperature gun. You want to see a 20 to 30 degree temperature drop from the inlet to the outlet. You can also use the same gun to check for cold spots in the radiator core that indicate a blockage.
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Good advice
 
williaml said:
what the GPM rate is .
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Also keep this tucked away in the back. OldManMopar is the first guy I remember posted this, and I'm pretty sure this happened to me.

The original 2 core 273 rad out of my 67 was pronounced "very clean and OK" by a rad man and "should" cool a 360 just fine. It did not.

As a low buck guy I ended up trying a SLANT newer model 2 core I had from a junker and cured the problem

WHY?

Possibly, according to the "OldMan" is that thermal cycling, etc, causes the fins to eventually crack loose from the tubes, meaning you can flow all the water you want-------it might not actually radiate heat.
 
Long story but here is the condensed version. The car had the original engine when found in a barn. The owner got the engine to run but he said it kept overheating. He switched the engine out for a 1969 engine. I buy the car and want it to be as original as possible so when I purchased the car I had the original 1965 engine rebuilt. Once installed I noticed the engine would run hot by the gauge. It would pin all the way to the right. Then it will back off but never in normal range. I have ordered a auxiliary temp gauge and temp gun but if I need to clean water jackets while the engine is in the car what is the best way to do such. Has anyone got any ideas?
 
williaml said:
Long story but here is the condensed version. The car had the original engine when found in a barn. The owner got the engine to run but he said it kept overheating. He switched the engine out for a 1969 engine. I buy the car and want it to be as original as possible so when I purchased the car I had the original 1965 engine rebuilt. Once installed I noticed the engine would run hot by the gauge. It would pin all the way to the right. Then it will back off but never in normal range. I have ordered a auxiliary temp gauge and temp gun but if I need to clean water jackets while the engine is in the car what is the best way to do such. Has anyone got any ideas?
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If the engine was rebuilt the water jackets are not the problem.
 
Could they have missed something in cleaning the jackets. Are there small passages where gunk could have not been flushed if not I'm going with the radiator
 
williaml said:
Could they have missed something in cleaning the jackets. Are there small passages where gunk could have not been flushed if not I'm going with the radiator
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There isn't anything inside an engine that could be left dirty enough during a rebuild to make it overheat.
This is a perfect excuse to buy a temp gun if you want one though.

Myself, I would grab the top radiator hose with my hand while it's hot, and then do the same with the bottom hose and make my determination from there.
If the bottom hose is way colder than the top one and the engine overheats that would tell me I either have a slow flow from the water pump or a blocked radiator.
If they were both about the same it would tell me I need a new or better radiator.

I learned to do things by elimination the old school way that doesn't cost money. :D
These days it seems people try to replace common sense and knowledge with cash and can't figure out why the money is gone but they still have a problem.
 
I am in complete agreement. Last week motoring around town for about 15 miles the top of the radiator was 194 the stat housing 192 and the bottom hose 130 then yesterday the stat housing was 220 the hose into the radiator was 195 and the bottom hose was 130 it was hot out yesterday but I don't think that had much to do with it
 
Does not sound like rad problem to me. Try a different 'good quality' stat. Those temps, tho, don't sound like "overheating" to me
 
I installed a new one last week. The thing that has me worried is that the 1967 engine was fine the radiator and gauge worked fine. Once installed the rebuilt 1965 engine the gauge shows hot. Could the water pump be the issue?
 
You need to determine if it's actually hot! Find a temp gun, or try Greg's suggestion about checking the hoses.
 
williaml said:
I am in complete agreement. Last week motoring around town for about 15 miles the top of the radiator was 194 the stat housing 192 and the bottom hose 130 then yesterday the stat housing was 220 the hose into the radiator was 195 and the bottom hose was 130 it was hot out yesterday but I don't think that had much to do with it
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So you do have a temp gun?
 
williaml said:
I am in complete agreement. Last week motoring around town for about 15 miles the top of the radiator was 194 the stat housing 192 and the bottom hose 130 then yesterday the stat housing was 220 the hose into the radiator was 195 and the bottom hose was 130 it was hot out yesterday but I don't think that had much to do with it
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Now see, if that 30 degree cooler coolant was circulating the engine wouldn't get hot.
It's moving so slow that its way hotter at the thermostat housing and comparatively colder coming out of the radiator.
It's either the water pump or the radiator.
 
I just looked online some water pumps have 5 blades some have 8 is there a difference for that car, I'm wondering. Maybe I installed a 5 blade water pump when an eight blade water pump should have been used.
 
williaml said:
I just looked online some water pumps have 5 blades some have 8 is there a difference for that car, I'm wondering. Maybe I installed a 5 blade water pump when an eight blade water pump should have been used.
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8 blade is generally for AC cars but I still used one in mine even though I don't have AC.
If you need/want a new one anyway you might as well go for it.
I didn't notice any major differences, but my car wasn't overheating in the first place.
The 26 inch radiator sure did the trick though, and was under 200.
 
It is almost impossible to find a radiator for this car. I shouldn't have to go to a bigger radiator just to cool the car?
 
I got this tip from a few guys right on here...a radiator for an '80 Aspen with AC fits (you just have to drill two holes in it for mounting). Under $200 from Rock Auto.

Use the Aspen upper hose and a '75 Dart 225 lower hose. That's what I did and mine runs no hotter than 195 on my underdash gauge.
 
First thing I would do is install a good quality mechanical temp gauge and see what it runs at around town and on the highway. You can actually see a temp change when the thermostat opens and closes with a good mechanical gauge in the car.

The OEM temp gauge has to many variables: resistance of sender unit, poor ground of sender to head, firewall connector, instrument voltage regulator output, etc.

Some machine shops knock the old freeze plugs into the block and leave them in there. seen this many times. I hope a good shop rebuilt your motor.

The reason for the different blade count on the water pump is A/C cars need to dump more heat, but they also have different pulley setups with different pulley diameters. So run the pump your car is supposed to use.
 
Honored Posters, With Respects,
A couple of Hard earned experiences to lend,

1)On block castings...
Blocks are an cast from 'composite' molds --- an internal & external--- then 'joined',
the 'freeze plug' holes are actually supports for the casting molds.
'Clean' water jackets do not equal smooth jackets, (read core shift & INTERNAL casting flash).
Any Internal restriction to coolant flow (see above) creates steam pockets.
In a constant coolant flow system (automotive) the net result is coolant temps
which vary ALMOST with ambient temps. Restrictions= state of change in the cooling medium.
2)On Infrared Handheld Pyrometers...
An excellent tool, the MOST singular drawback however is the surface of the material
being 'scanned' ... Irregularities, color changes, surface angles, holding angle point to point on multiple reads... I have seen as much as 40 deg F change between readings...

Thx for the Grace Honored Posters :D

williaml,
Apologies for the hijack,
--- don't overthink--- observe & report!
 
Aaron you did the Aspen rad with an Aspen 80 upper and a 75 Dart lower hose on a 1965 Dodge Dart?
 
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