440 thermostat?

[Wietse]

Do you have a infrared temperature gun?
What is the radiator outlet water temperature?

 

[Sonny]

Do you have a infrared temperature gun?
What is the radiator outlet water temperature?

I’m ordering one today

 

[Wietse]

Not sure you tried already, but put the interior heater on max. and allow it to help to cool.
If that brings the temps down for sure your radiator cannot dissipate the heat, either too much air flow restriction due to a too dense core maybe? Or coolant flow is too fast?

 

[Sonny]

Not sure you tried already, but put the interior heater on max. and allow it to help to cool.
If that brings the temps down for sure your radiator cannot dissipate the heat, either too much air flow restriction due to a too dense core maybe? Or coolant flow is too fast?

Yeah I’m in Florida so I disconnected the heater core. Was using high flow pump, went back to stock and cooling improved greatly under 50 mph. Hit the highway and it’s still 210.

 

[Sonny]

Yeah I’m in Florida so I disconnected the heater core. Was using high flow pump, went back to stock and cooling improved greatly under 50 mph. Hit the highway and it’s still 210.

I didn’t have this issue last year when I had 271 gears. Only since adding 355 gears does it get this hot on highway.

 

[wyrmrider]

seal the core support & around the radiator
valance under the core support
harbor freight has temp gun for as low as 16 0n sale
i take it you have checked the timing
that rad sould do it ????
pt ok? oops that's pressure test
did you do the high flow stat?
does your model have the bypass in the pump housing?
also some models had the bypass included in the heater valve

 

[Wietse]

I didn’t have this issue last year when I had 271 gears. Only since adding 355 gears does it get this hot on highway.

Likely the increased thermal load by higher rpms is showing the underperformance of the cooling system.
The reason Mopar added a 26" radiator to the performance axle packages.
Looking at pictures of the Champion radiators the core seems very dense in cooling fins, the more dense the more forced cooling it requires obviously to force sufficient air through.
Do you have a stock type radiator left? That would be my try now.

 

[Sonny]

seal the core support & around the radiator
valance under the core support
harbor freight has temp gun for as low as 16 0n sale
i take it you have checked the timing
that rad sould do it ????
pt ok? oops that's pressure test
did you do the high flow stat?
does your model have the bypass in the pump housing?
also some models had the bypass included in the heater valve

Yes on sealing radiator to support.
Valance yes.
initial 18, total 34
Ported vac advance
Milodon high flow stat
Bypass in housing
Stock water pump. Seems to work better than the high flow at lower speed.

 

[Sonny]

Likely the increased thermal load by higher rpms is showing the underperformance of the cooling system.
The reason Mopar added a 26" radiator to the performance axle packages.
Looking at pictures of the Champion radiators the core seems very dense in cooling fins, the more dense the more forced cooling it requires obviously to force sufficient air through.
Do you have a stock type radiator left? That would be my try now.

Of course I sold it but it wasn’t flowing great. If removing the trans doesn’t effect the temp I’ll be looking at the radiator.

 

[Wietse]

The OEM radiator, in clean condition obviously, should be sufficient already to keep the engine cool.
These modern radiators do have the cooling capacity but require a hell-uv-a-lot more airflow which is just not given by these cars bumpers and grilles they have.
Bypassing the trans cooler section will help some, but quite sure it will not solve your issue.

My car, Coronet R/T, with a 440 has a 26" radiator, stock cooling pump housing with 440source pump and using a Flex-a-Lite direct driven fan and have no cooling issues at 90 Deg F outside temps.
Nothing crazy, no all High Flow equipment etc, just simple stuff but it works.

I think all this high flow equipment is for things like drag racing, short time high flow cooling circuit to survive the pull and after sufficient time to cool down.

 

[Sonny]

The OEM radiator, in clean condition obviously, should be sufficient already to keep the engine cool.
These modern radiators do have the cooling capacity but require a hell-uv-a-lot more airflow which is just not given by these cars bumpers and grilles they have.
Bypassing the trans cooler section will help some, but quite sure it will not solve your issue.

My car, Coronet R/T, with a 440 has a 26" radiator, stock cooling pump housing with 440source pump and using a Flex-a-Lite direct driven fan and have no cooling issues at 90 Deg F outside temps.
Nothing crazy, no all High Flow equipment etc, just simple stuff but it works.

I think all this high flow equipment is for things like drag racing, short time high flow cooling circuit to survive the pull and after sufficient time to cool down.

I agree. Just going back to the stock housing and pump I went from 195 degrees down to 185 driving under 50 mph this week.

 

[Wietse]

I agree. Just going back to the stock housing and pump I went from 195 degrees down to 185 driving under 50 mph this week.

Indeed, when it comes to building/modifying a car/engine i heard someone say; "just stick with what you got and keep it simple".
And the more i think about it the more i believe he is right.
I think if you are able to borrow a 26" radiator just to try you should be seeing cooler temperatures.

 

[Kozlow]

Hey Sonny does your right side exhaust manifold still have the heat crossover valve in it?
Maybe it isn't opening up all the way, and restricting your exhaust flow.

 

[Sonny]

Hey Sonny does your right side exhaust manifold still have the heat crossover valve in it?
Maybe it isn't opening up all the way, and restricting your exhaust flow.

Great question but it’s gone.

 

[wyrmrider]

you can tap and plug the bypass in the housing and make a bypass in the heater circuit with a shut off
have it normally open and shut if you get hot
as cooling by radiator is mostly by frontal sq in not thickness going to a wider core support (or sawzall)
I had an 440 C body radiator in my b body
watch the height
but try the remove the trans cooler from the radiator first
what cooler did you get
got a pic

 

[Sonny]

you can tap and plug the bypass in the housing and make a bypass in the heater circuit with a shut off
have it normally open and shut if you get hot
as cooling by radiator is mostly by frontal sq in not thickness going to a wider core support (or sawzall)
I had an 440 C body radiator in my b body
watch the height
but try the remove the trans cooler from the radiator first
what cooler did you get
got a pic

I bought this cheaper tube and fin to see if it improves my cooling. If my cooling comes down, I will switch to a plate type cooler. I made a bracket and mounted it 3” in front of the radiator.

 

[wyrmrider]

you need to either put it against your radiator or duct it or air goes around not through
what size fittings
should work if you are not towing
let us know if it works to reduce rad temp

 

[Sonny]

I

you need to either put it against your radiator or duct it or air goes around not through
what size fittings
should work if you are not towing
let us know if it works to reduce rad temp

Its actually 2.5” from radiator at the top and 1.5” at the bottom. I’ll put the plate cooler closer. Using factory steel 5/16” lines with -6an fittings and 11/32” hose.

 

[Sonny]

you need to either put it against your radiator or duct it or air goes around not through
what size fittings
should work if you are not towing
let us know if it works to reduce rad temp

I took the trans completely off the radiator and saw good improvement. Under 55mph it runs at 182* with fans off (fans off for the first time!). Highway it maxed out at 196* fans on, with fans off it started creeping up to 198* so I turned fans on and it held it there. Came off highway, had a quick spike to 210 but was short. Drove home at about 195* at 45 mph but can’t come back down.
sounds like my weakness is the radiator? Should be able to cruise fans off at 75mph no problem and it won’t. Guess my 3 row 1 year champion radiator ain’t up to the task.

should I go back to an original Mopar 26” radiator? Find a used one and get it re-cored?

 

[wyrmrider]

Looks like you're good
have you tried the 75mph test yet?
did your old radiator have round top or squarish tops square headers are better