440 Highway temps

[zombezoo]

Can you tell the efi to add more fuel at cruise? Or tell it to pull some timing? I don’t know what you have, just tossing that out there. Almost thinking the o2 is giving bad info or something like that.

A guy on Moparts has posted several times about a car in his shop having a new core that had weird overheating problems. He said he called green ray and the man himself said new cores aren’t made as well as they were in the day, but his were made to the old specs, not cost cutting ones. He pledged to personally fly to the shop if his radiator didn’t cure the issue and it did in fact solve the problem.

Read my mind, its a Fitech setup. I dont have timing control so I have a recurved factory unit. As for fuel I reset the fuel learning on the system and left the targets in the mid 13s, it did not make a difference.

The last thing before I replace the radiator with an aluminum unit will be to play with the timing some more. I bought one of those limiting plates for the factory distributor and I intend to make a shorter curve so I can run more initial. The idle is a lot smoother at 14+ base but the curve would be too aggressive at WOT. I currently run about 8 base.

 

[Some Car Guy]

Hmm. Setting the timing up that way would be nice, but I’m not thinking that is causing this.

What fan clutch? Maybe try a factory solid spacer just to see what happens. Hood seal could do something for this, but again seems like a reach to get temps where they should be. A Flowkooler and a clean radiator should be a desert cooler.

I’d give it a whirl with telling the ecu to run it at like 11.5-12 as the target at cruise and see what that does. Just as a quick test.

 

[josephqatarcarguy]

I have to believe that 110+ degree temps would be much worse for me. I can tell the difference between 80 and 90 degree days. Once the temps are in the 70s, the problem largely goes away.

i had the same symptoms ... temps down and it would be fine , lucas super coolant helps alot , try it

 

[josephqatarcarguy]

Read my mind, its a Fitech setup. I dont have timing control so I have a recurved factory unit. As for fuel I reset the fuel learning on the system and left the targets in the mid 13s, it did not make a difference.

The last thing before I replace the radiator with an aluminum unit will be to play with the timing some more. I bought one of those limiting plates for the factory distributor and I intend to make a shorter curve so I can run more initial. The idle is a lot smoother at 14+ base but the curve would be too aggressive at WOT. I currently run about 8 base.

i too run a fitech

 

[zombezoo]

Hood to rad support seal is contacting, I think it's ok. This morning was in the high 60s so. No issues. I may be out of time to troubleshoot this problem this year. Temps in the mid 60s this week. This may be a next summer problem

 

[zombezoo]

Hmm. Setting the timing up that way would be nice, but I’m not thinking that is causing this.

What fan clutch? Maybe try a factory solid spacer just to see what happens. Hood seal could do something for this, but again seems like a reach to get temps where they should be. A Flowkooler and a clean radiator should be a desert cooler.

I’d give it a whirl with telling the ecu to run it at like 11.5-12 as the target at cruise and see what that does. Just as a quick test.

My understanding is that the fan clutch should really not be contributing to temp control at highway speeds. The car runs cool at idle and in stop and go suggesting to me that the fan clutch is doing a good job.

Edit: Its new also. It corrected warming temps at idle I was having initially.

 

[Jackpot50]

Fan shroud? or rubber strip between hood and radiator support

 

[Jackpot50]

A bit of an odd situation:
73 satellite 440 swap
Recored factory radiator
180 degree tstat
New fan clutch and 7 blade fan
Factory ac condenser installed but not charged
Fins are clear

Idle and around town the thing runs on the gauge line, approximately 200 degrees on the coolant temp sensor installed for the EFI system in the water pump housing

Highway temps over 70mph spins the motor 2500rpm+
Temps will climb into the 230s on the CTS, just under half way on the gauge

I pulled over with the ir temp gun:
Upper radiator hose 180
Lower radiator hose 135
Radiator core 125-130
Water pump housing 220

Seems to say pump is not moving coolant, I had it apart and the impeller looked great, tight on the shaft, not leaking.
Engine is an RV unit, using all the rv pulleys
I choose not to change the water pump because the unit in the engine had an impeller that was larger than the replacement unit I purchased and I was concerned I had the wrong pump.

Any insights here? I know there are different pumps, pulleys and housings but I would have thought keeping all the RV stuff together would be ok.

Again, around town and sustained speeds up to 50 mph, it's fine. It's extended higher rpm runs that seem to be a problem

fan shroud and rubber strip between hood and radiator support to make fan pull air thru. radiator not over it

 

[Some Car Guy]

My understanding is that the fan clutch should really not be contributing to temp control at highway speeds. The car runs cool at idle and in stop and go suggesting to me that the fan clutch is doing a good job.

Edit: Its new also. It corrected warming temps at idle I was having initially.

It’s not supposed to need a fan at speed, but I’m grasping for a reason this isn’t working. Or if it is dropping to a speed where this creeps in as an issue. If it solved the idle problem then it’s likely ok then. This seems more and more ore to me like you have an issue with the core itself. Any chance you have another one to toss in there?

 

[GTXDAN]

I'm not familiar 73 b body, but is there an air seal panel at the bottom of the radiator/core support that goes forward and attaches to the bumper or grille assembly some where. This panel is there to keep the air going through the rad instead of out the bottom of the car. Just a thought.

 

[zombezoo]

It’s not supposed to need a fan at speed, but I’m grasping for a reason this isn’t working. Or if it is dropping to a speed where this creeps in as an issue. If it solved the idle problem then it’s likely ok then. This seems more and more ore to me like you have an issue with the core itself. Any chance you have another one to toss in there?

I decided to just order the cold case unit. I think that's the issue as well. We shall see once it arrives. Will update in about 2 weeks when I have time to install it.