I need help to build a heavy duty cooling system

[cekautsky]

Question#1:
Would you expect to see a measurable drop in water temp by installing a remote trans cooler? I`m thinking about going with a remote trans cooler because my water temp runs 180 to 200 around town and easy offroading. Temps shoots up quick to 220+ on extended uphill runs. Current trans cooler is in the Ron Davis (RD) aluminum radiator with 17inch pusher fan, flowkooler water pump, and a 180degree stat.

Question#2:
Is a Heavy duty copper/brass radiator better for cooling? I am tossing the idea around of going back to a heavy duty copper/brass radiator. I have heard others suggest that water flows too fast through the RD aluminum radiators for best cooling. Im not 100% convinced about this theory but it is something that i am thinking about. My goal is to build a bullet proof cooling system for my 1974 with stock 302 & c4 so that i can run the 100+ degree AZ desert.

Before i just start throwing money at it i thought i would see what you guys have done to address cooling issues. Any advice would be greatly appreciated...



Thanks in advance for your input.

 

[stlo]

My water temps stay at 180 all day long no matter how hard I push it with an alum. Rad......I would try putting a cooler on your trans before it gets to your rad. And see if that helps before I went through all the trouble of swapping rads.....that trans fluid in rad cooler will transfer a lot of heat to the water especially bein a alum rad.....go buy a cheap trans cooler with fan would be best or try a cheap one with out just to see if it helps....I bet u will be surprised how much of a diff it makes

 

[carmi]

I would strongly suggest going to a puller fan for better efficiency. I went from the WH staggered 4 core to their Ron Davis aluminum and now have a hard time getting over 190 with a 185 t stat. Before the aluminum radiator I would reach 220 on hot days and pulling any hills. That said, it still never got over 190 when wheeling. I also saw good gains from the flow cooler water pump and undersized water pump pully to increase water flow and fan speed. For the fan I used a rigid 5 blade with a fan clutch. My personal opinion is that pusher fans not only block the radiator and restrict flow but by their very nature do not flow nearly as much air past the radiator as a pull through design. Something else to check would be your timing. Too much or to little can cause overheating problems. Also check your plugs, is the motor running lean? Even for a bronco, it shouldn't be an issue to keep it under 190 when putting around and wheeling.

 

[70_Steve]

Wow! A member since 2010 and this is your first post?!?! Well, let me say welcome to CB.com!!! And, it's about time!!!

I'm in Phoenix, and regularly wheel when it's 110°+ and don't overheat. I'm running a 4 core copper radiator that a shop made for me using the stock tanks. Other than that, the rest of the cooling system is pretty much stock. Stock 7 blade fixed fan, use to run stock pulleys, but I build a serpentine system. The pulley I run now is the same diameter though. I run a Flowcooler waterpump, but only because I needed a new WP and Wild Horses had them on sale. I have a metal shroud that I got from Driven 4x4, but only because the stock plastic one cracked. The only other thing I've done is install "bypass" hoses on both sides of the rear intake manifold on the 351 and route them to the heater hose return.

Tell us something about your current cooling system. Also update your profile to include where you live.

And, are you coming to the Stampede???

 

[Broncobowsher]

Shroud with an engine driven cooling fan will do wonders. The Ron Davis units have a pretty tight fin pitch and require a strong fan to make them cool well.

Electric cooling fans in Broncos generally don't work. The few that do have a very heavy amp draw (40A+). The fact you generally have enough cooling despite only having a minimal cooling fan shows that it is in pretty shape. A little more fan should do it.

Nothing wrong with a pre-cooler external transmission cooler added in.

 

[jw0747]

A stock rigid blade fan with a metal shroud will keep it cool all day long. Flex fans flatten out and don't pull as much air as rigid fans.

 

[cekautsky]

Thanks for all of the info so far. Based on what i have read my plan it to take it one step at a time so i can track the results of the changes. First I think i will add in a remote trans cooler and see if i get a drop in temps across the board. After that I think I will pull the 17inch pusher and go back to a fixed blade with fan clutch and stock shroud. Lastly, I will consider a copper/brass radiator. Hopefully i wont have to because the aluminum rad is so pretty...

Ignition timing should be good but i will go back and check the total advance. In my experience with SBF 34 to 36 total should be good. Plugs look good with even medium brown color.

I will update my progress as i go...

Stampede... Sounds fun but not this time. Still recovering from kids college tuition.

 

[cekautsky]

A stock rigid blade fan with a metal shroud will keep it cool all day long. Flex fans flatten out and don't pull as much air as rigid fans.

I have the stock 5blade fan still. Should I use that or go with a different rigid blade fan? I have a flex blade too that i could try.

 

[sanndmann3]

X2 on dumping the pusher fans. I have also heard they are more of obstruction than anything else. I ran a Ron Davis for many years and thought it was a well made piece.

 

[bronconut73]

Your Ron Davis radiator is a great unit (wish I had one).
Sounds like you just need more fan and check your water pump pulley. A smaller one will spin your pump and mechanical fan faster at idle speeds which usually helps too.
These cooling issues almost always seem to be simpler than we think.
Many of us have spent a small fortune to track down cooling issues only to find it was something simple....sigh....
But you sound like you have a good system in place, you just need a rigid 7 blade fan.
BTW I think I have heard that Fords asymmetrical 7 blade is quiter than a typical 5 blade while moving more air. Tough to beat that.

 

[jw0747]

I have the stock 5blade fan still. Should I use that or go with a different rigid blade fan? I have a flex blade too that i could try.

Stock rigid 5 blade is fine.

 

[cekautsky]

I just wanted to post an update regarding the recent changes to my cooling system i made based on all of the advice i received from you guys. What i ended up doing was simply removing the 17inch electric pusher fan and went back to a 18inch mechanical fan. I used a six blade flex fan that i had previously purchased from Toms. I figured i already had it on the shelf so why not use it and see if i am on the right path before i invest in a 7 blade rigid fan that was suggested. I spaced the fan 1.125inch away from the radiator so that the fan is running with about half of the blade inside of the shroud. I also used the factory fiber fan shroud. Just to recap my system details, I am using a Ron Davis Aluminum radiator, flowkooler water pump, and silicone radiator hoses. Well the first results are in and it seems to have made a huge difference going back to the mechanical fan. It has dropped my overall temps by approximately 20 degrees from my previous arrangement. I was pleased that the new mechanical fan setup was fairly quiet. I plan to take it out to Parker, AZ in two weeks for my wife's birthday trip (how cool is it that my wife wants to go 4x4ing for her birthday) so i will have a chance to give it a good test. But so far by just running it around town it looks like my heating problems may be over. Thank for all your help and i will post up again with the results from my upcoming test run. CK

 

[hyghlndr]

Try water wetter to drop the temp some, I also just installed a high end electric fan setup (big pull with small pusher) and flowkooler pump on my replica car which dropped the temp 30 degrees.

 

[70_Steve]

Good news! Look forward to an update after the Parker trip. I hear wheeling there is a blast. I haven't been yet.

 

[broncnaz]

Hmm a couple of weeks? 20-22 mar? You may want to head over to the AZ bronco stampede if the weekend matches only a few more hours drive than parker.. One last suggestion would be to run a 195 t stat as you will get more heat transfer out of the radiator with the hotter t stat during the hotter weather.

 

[70_Steve]

Hmm a couple of weeks? 20-22 mar? You may want to head over to the AZ bronco stampede if the weekend matches only a few more hours drive than parker..

Only another hour 45 minutes

 

[sykanr0ng]

One thing with aluminum radiators is that aluminum is very prone to metal fatigue.
What this means for a Bronco is that an aluminum radiator must be isolated from the body which flexes quite a bit during off road driving, leading to the radiator cracking.
Aluminum radiators cannot be repaired at a reasonable cost they must be replaced.

So they are best as a cheap disposable radiator, like the junkyard Explorer 4.0L radiators.

The OEM's switched to aluminum because it costs less than half what copper and brass do, not because it cools better.

 

[Chub_Rock]

Wow! A member since 2010 and this is your first post?!?! Well, let me say welcome to CB.com!!! And, it's about time!!!

I'm in Phoenix, and regularly wheel when it's 110°+ and don't overheat. I'm running a 4 core copper radiator that a shop made for me using the stock tanks. Other than that, the rest of the cooling system is pretty much stock. Stock 7 blade fixed fan, use to run stock pulleys, but I build a serpentine system. The pulley I run now is the same diameter though. I run a Flowcooler waterpump, but only because I needed a new WP and Wild Horses had them on sale. I have a metal shroud that I got from Driven 4x4, but only because the stock plastic one cracked. The only other thing I've done is install "bypass" hoses on both sides of the rear intake manifold on the 351 and route them to the heater hose return.

Tell us something about your current cooling system. Also update your profile to include where you live.

And, are you coming to the Stampede???

Steve, is that a bypass radiator? Like the BC Broncos triple pass? I'm overheating at highway speeds. I'm ok around town or on trail, but over 8 miles on freeway and I creep over 220 til gurgling. Running a 351W, flowcooler, 7 blade flex mechanical fan, w/ fan shroud. My radiator doesn't have zig zagged fins, only straight down. I'm thinking radiator, but want to educate myself as much as I can before the expense. Any other recommendations are appreciated. I'm considering the intake bypass "thingy". Thanks

 

[blubuckaroo]

Question#1:
Would you expect to see a measurable drop in water temp by installing a remote trans cooler? I`m thinking about going with a remote trans cooler because my water temp runs 180 to 200 around town and easy offroading. Temps shoots up quick to 220+ on extended uphill runs. Current trans cooler is in the Ron Davis (RD) aluminum radiator with 17inch pusher fan, flowkooler water pump, and a 180degree stat.

Question#2:
Is a Heavy duty copper/brass radiator better for cooling? I am tossing the idea around of going back to a heavy duty copper/brass radiator. I have heard others suggest that water flows too fast through the RD aluminum radiators for best cooling. Im not 100% convinced about this theory but it is something that i am thinking about. My goal is to build a bullet proof cooling system for my 1974 with stock 302 & c4 so that i can run the 100+ degree AZ desert.

Before i just start throwing money at it i thought i would see what you guys have done to address cooling issues. Any advice would be greatly appreciated...



Thanks in advance for your input.

#1...
No you won't see a big difference. That teenie tranny cooler line adds zip to the cooling load compared to the motor heat load. Still yet, adding an aux cooler can't hurt by cooling the tranny fluid a bit more. Just install it so it's downstream of the radiator cooler.

#2...
Brass/copper transfers heat better than aluminum. Brass/copper radiators can be repaired more easily too. Be aware that the four core radiators are so thick that the back tubes are practically useless and restrict the air too. Three core radiators can flow more air. The best have staggered tubes and are referred to as "X-cores."

 

[70_Steve]

Steve, is that a bypass radiator? Like the BC Broncos triple pass? I'm overheating at highway speeds.

No, it's nothing fancy like the triple pass radiator. But I really don't know specifics like fins per inch and that sort of stuff.

Typically, if you're overheating at speed, you aren't getting enough air through the radiator. It there anything (winch, PS cooler, electric fans, etc) that would block air flow through the radiator?

As an inexpensive troubleshooting task, just pull the radiator and take it to a shop. Explain the problem to them, and have they examine the radiator.