more cooling issues

[major]

I run a 3 core 5.0 Aluminum radiator that is brand new with shroud and flex a lite 16 inch steel fan (the black one with the short fixed blades) pretty much stock 5.0, stock water pump, coated headers but I run a carb instead of EFI.

Timing is set, carb is tuned and it still idles at least 210 and climbing with the AC on. I have right at 3" of space from the front of my water pump pulley to the radiator. When I installed my fan, I used a 1/2" spacer that puts my fan less than 3/4" from my radiator.

I have not found a small pusher to mount in front because my hood latch. Any help would be appreciated.

 

[broncnaz]

AC does tend to make for higher operating temps. Do you have a solenoid on the carb to kick up the idle speed when the AC is on? Its kinda standard to kick the idle up so the fan pulls better. What temps do you run when going down the road?
Might consider a larger fan if you can fit one 18". Might also want to change your thermostat as it could be either stuck open or is not opening like it should. I'd stick with a 195.
Might also want to verify the actual engine temp with a mechanical gauge.

 

[72Sport]

I run a 3 core 5.0 Aluminum radiator that is brand new with shroud and flex a lite 16 inch steel fan (the black one with the short fixed blades) pretty much stock 5.0, stock water pump, coated headers but I run a carb instead of EFI.

Timing is set, carb is tuned and it still idles at least 210 and climbing with the AC on. I have right at 3" of space from the front of my water pump pulley to the radiator. When I installed my fan, I used a 1/2" spacer that puts my fan less than 3/4" from my radiator.

I have not found a small pusher to mount in front because my hood latch. Any help would be appreciated.

At idle the hot air in the engine compartment ,with the hood closed, is sucked over the top of the radiator and is back through the radiator. In effect you are trying to cool the engine with very hot air when the Bronco is not moving. The longer it sits at idle the hotter the air in the engine compartment the hotter the engine temperature. If you let it sit long enough you will probably hurt something. I have a serpentine system in mine and use a 17" reverse rotation Flex Lite fan #1517. I also have 2 8" Derale fans in front of the radiator for better cooling at idle for both the AC and me. Ac is much more efficient with some air moving over the condenser when sitting still. Also the condenser is to the compressor what the radiator is to your engine. If yours is v-belt you might try a stock 7 blade fan or a 1517 stock rotation fan.

After doing a lot of research with thermocouples and hand held thermometers I wrote an article for Bronco Driver Magazine. It is in issue #12 Pg 59 "Cooler Bronco at Idle with AC". If you don't have access to the magazine I believe you can down load it from their website for a fee. The AC has been trouble free for the last 8 years. I have never had an over heating problem at idle. I drove the Bronco to Lake Havasu AZ several times last year in June & July when temperatures were about 115f.

 

[major]

I have a serpentine system and reverse rotation water pump as well. I will try that fan. My condenser is installed in front of my radiator and if I could see a pic of where you mounted the 2 8" fans that would be a big help. I just can't find the room???

The mechanical fan shroud is fiberglass by the way and thanks for the help.

 

[72Sport]

I have a serpentine system and reverse rotation water pump as well. I will try that fan. My condenser is installed in front of my radiator and if I could see a pic of where you mounted the 2 8" fans that would be a big help. I just can't find the room???

The mechanical fan shroud is fiberglass by the way and thanks for the help.

I am on my out for the evening. Everything is in the magazine article. You need to get rid of the hood latch and possibly the prop rod. The fans barely fit between the condenser and the grill. I'll get pictures tomorrow if needed.

When you block the front of the radiator with a condenser the area between the condenser and the radiator is the path of least resistance for air travel. Since the air is pressurized in the engine compartment the hot air travels down from the hood and into the radiator to keep it warm.

I have a Mustang 86-93 serpentine system.

 

[blubuckaroo]

Make sure your idle speed is at least 650 RPM. Idle speed set too low won't let the fan move enough air and result in higher engine temp as well as high head pressure in your A/C. Also coolant flow will be too slow to do a good job. If it's a auto trans it can be really tough to get the idle just right so you have at least 650 RPM in gear but not so fast that the engine diesels when you take it out of gear and shut it off. Some came with a anti-diesel solenoid just for that reason.

 

[DirtDonk]

I'm surprised that you needed a spacer for your fan. Does it place it properly in the shroud?
2/3 of the fan blade width should be inside the shroud, 1/3 outside.
Kind of hard to gauge on the Bronco shrouds though, as the top section is much deeper as a protective measure and to keep air from washing out over the top of the blades. So look along the lower edge to see where it puts the fan.
It might be perfect, as that 3/4" clearance sounds pretty typical, but I wanted to mention that stuff.

Some other things that help with what 72Sport was saying are using shields to keep the airflow going through the radiators and not around them.
Sealing off the area between the grille and core support under the hood, and sealing off the sides of the radiator tanks to the core support, can go a long way to "encouraging" air to flow through, rather than around.

I don't know that it's the cure for everybody's cooling issues, since not enough people have gone that route yet. But as long as your water flow and fan capacity and radiator capacity are sufficient, it's a good place to start.

Paul

 

[carmi]

A high flow water pump and an overdrive water pump pulley made a huge difference for me.

 

[jw0747]

toss the flex fan and install a solid blade mechanical fan...

 

[Rox Crusher]

I run the OEM clutched fan from an Explorer (steel blade version) and it works great.