Bronco Cooling System

[Tjboriack]

If it's only while under load, it could be your trans temp that's making it overheat if they share the radiator. If so, you could try adding another trans cooler with a fan to keep that cooler or completely separate them.

Also, just confirming that you do NOT have a reverse rotation pump as your rad is stock sided.

pretty certain the rotation is correct on the water pump - been a little while since I replaced it but was a big watchlout for me then.

Have thought about something separate for the trans cooler - just working through the other steps I have available first.

 

[Tjboriack]

And by all means, try the AC just to see if it goes up when the temperature is otherwise stable when you’re driving.

have tried the A/C - it is fine going down the road - does at a few degrees, but not horrible. Sitting in traffic it definitely runs the temp up faster, so I just leave it off for the most part. also cruise with the windows down for the most part, so no use trying to air condition the world. Would be nice to have it for the summer trips though.

 

[Tjboriack]

That air dam works great, and I highly recommend it, but only helps when moving. Really helps though, at least for me!

just ordered it, it's an easy add-on that I can do when I tear into it next and plenty of people on a variety of threads in this forum have mentioned adding it.

 

[Timmy390]

Really like to know what the base timing is at.......

Tim

 

[ba123]

pretty certain the rotation is correct on the water pump - been a little while since I replaced it but was a big watchlout for me then.

Have thought about something separate for the trans cooler - just working through the other steps I have available first.

you could always try putting a hose temporarily between the inlet of the rad trans cooler and the exit so that the fluid doesn't go in and just bypasses it, or something like that and see if your heat issue disappears. I would only do this on a not too long drive and hopefully know that your trans doesn't get too hot. I can't imagine the trans would overheat if you're just sitting in gear but it also shouldn't take long to tell the difference if that is the problem.

 

[Tjboriack]

Alright folks - I finally had some time to get back to the Bronco. I have made the following changes - moved from a 5-15/16" water pump pulley to a 5" pulley, and changed the antifreeze to a 60/40 water/antifreeze mix.

Rechecked the timing and the base line timing was running close to 20 degrees so I reset it to about 10 degrees (+/-2 degrees)

Took it for a drive and the first drive it stayed around 190, sat in the drive way with it in gear at an idle and it maybe touched a needle width over 195. Did not turn it off, then took it for another drive on the highway and drove about 75mph for 10 minutes, and temp went up to ~205. Let it sit in idle for a few minutes while I ran in to a store to pick some stuff up, temp didn't climb, got back on the highway and drove 65mph and temp came back down to just over 195. turned on the A/C (not for very long because I was close to home already) and it didn't change the temperature.

Once home I added the Wildhorses air dam and will be driving it later - let you guys know if it changes. Also plan on running the A/C longer

Right now I am happy as there is some marked improvement, but that is with it being a sunny 90 degrees outside, so may be awhile before I get to drive it in really hot weather and sitting at traffic lights.

 

[Tjboriack]

The air dam looks pretty good installed.

 

[Tjboriack]

Really like to know what the base timing is at.......

Tim

base timing was at ~20 degrees - moved it back to about ~10

 

[Broncobowsher]

I would like to see a picture of a fan blade, as it is installed on the Bronco.
Reason being is if the fan is flipped it will still move air in the correct direction, just not as good of a job at doing it. I've seen fans flipped in order to gain clearance or just because it looks right. Nothing to do with rotation, but how well the fan scoops the air and pushes it. Sometimes a flipped fan makes for nearly no airflow, other times it is just reduced from what it could be.

 

[Tjboriack]

I am curious as to the thoughts of how much heat the transmission may be adding if the lines are flipped. looks like I have hot/pressure going in on the lower port, and the return to the transmission out of the top of the radiator.

 

[Tjboriack]

I would like to see a picture of a fan blade, as it is installed on the Bronco.
Reason being is if the fan is flipped it will still move air in the correct direction, just not as good of a job at doing it. I've seen fans flipped in order to gain clearance or just because it looks right. Nothing to do with rotation, but how well the fan scoops the air and pushes it. Sometimes a flipped fan makes for nearly no airflow, other times it is just reduced from what it could be.

see the image - the air flow pull can hold cardboard on the front of the a/c/ condenser at an idle

 

[Broncobowsher]

That's correct. Should have simply stated that the concave side faces the engine. convex side the radiator.
It does look like the belt alignment for the A/C is a little off. Maybe just photo angle? But that angle it looks like the compressor needs to move forward about a quarter inch.

 

[ba123]

I am curious as to the thoughts of how much heat the transmission may be adding if the lines are flipped. looks like I have hot/pressure going in on the lower port, and the return to the transmission out of the top of the radiator.

I really think it depends on the radiator but believe the main effect would be on your transmission cooling and not so much your radiator heating...although it's certainly possible.

I still like the idea of bypassing the trans line by removing and connecting the two together to see if you still have an issue, as long as you can be sure not to overheat your trans.

You could try that and then if it does make it work correctly, then you could try swapping the in/out to the correct location and check again and just use an external if you overheat no matter what when it's connected.

 

[Broncobowsher]

I am curious as to the thoughts of how much heat the transmission may be adding if the lines are flipped. looks like I have hot/pressure going in on the lower port, and the return to the transmission out of the top of the radiator.

No difference. You still have to dump the heat out of the trans into the water. If the cooling of the trans gets worse, it gets hotter, and will get back into a greater temp delta across the cooler which will end up dumping the heat back into the coolant just like it was.

Generally (not always) the flow is bottom to top. Helps drive out air bubbles. If top down, any bubbles would need to be pushed down to get out of the cooler. Car radiators are the only common down flow heat exchanger I know of. But they also have ways of dealing with air bubbles that get in them that sealed coolers don't have. Find a rear engine car with a front radiator and you will find struggles with hidden air pockets in a cooling system.

The good thing is most in radiator coolers have narrow enough passages and the trans fluid has enough velocity that they can usually force and air pockets out. So they can generally be hooked up backwards and still work.

In the end it is still just an 8" heating element in the cold side of the radiator. Doesn't really matter which way the heating element is aimed, it is still a heating element. And the trans cooler is in a water bath of pretty quick flowing water, it is going to give up it's heat either way.

 

[jckkys]

I smile when I see people write about 90 degrees as being hot. To me and many other desert dwellers here in Az we just call that summer. Hot is over 110. So I've been fighting heat for over 45 yrs. in 3 EBs. Everything mentioned above has been tried alone and in combination with others. A complete rebuild of the radiator and engine helped more than any of them. The cooling system itself is nearly stock and it never hits 200 degrees. The radiator is a high density 3 row with stock OE tanks. The fan is OE. So are the shroud and pulleys. I always advance the timing till I get some pre-ignition at any RPM and load. Then I back off 2 degrees. That means 20 degrees initial to start with. Any less, it runs hotter and has less power. That's after raising the compression ratio from 8.7 to 9.5 to1. The factory specs were all about emissions, not HP or MPGs. The stock 195 thermostat is as good as any. Most of my cooling improvement came from a clean/new radiator core and boiled out block and heads. 47yrs. can leave a lot of rust etc. in the cooling system. The Ford engineers did a better job than most are willing to admit. The frontal area of EB radiators is small to fit between the frame rails. So good maintenance is more important than with other vehicles.

 

[Madgyver]

Many things to consider here. Timing? all in under load? I'd play with to see differences.

For my set-up, New motor, WH tri-pass radiator, DeltaPAG 18" brushless fan, custom fan shroud, radiator moved close to grill while still retaining factory hood latches. This set-up works for me. Took a few fans to figure it out, I just wanted to drive...