MY build thread...'88 Bronco II Desert Rat Patrol Edition: MAJOR update 2/23/2025

[Peter Griffin]

I'm hoping @Uncle Gump, @lil_Blue_Ford, @RobbieD and some of the other folks who have been REAL helpful can weigh in on this one...

I ordered a factory/OEM styled radiator (not Motorcraft) to see if there was going to be anything different from the Alloy Works one(s) that haven't been up to task seemingly. I was mostly concerned with the angle of the upper radiator outlet in particular.

Initially it didn't appear different to me which frankly got me a lil agitated. When I was begrudgingly in the process of packing it up to send it back to Parts Geek I noticed that it looked significantly thicker than the Alloy Works ones. Measuring confirmed that the Alloy Works were 1.75-inches thick, and the OEM-style was 2.25-inches. That massive difference got me thinking that was the reason why the cooling couldn't keep up.

So, along with a variety of hoses for my BII and later model 4.0 Exploders, a 180-degree thermostat and new radiator cap I decided to swap them out yesterday. I had to remove the universal fan shroud and bought an zip-tie style oil cooler installation kit to mount it to the new radiator...which I didn't get exactly right since the fan blades will now strike if I hit I hard enough bump but that's easy enough to rectify...

I expected it to run cooler with the new (lower) thermostat and it did. It took quite a bit longer for it to reach operating temp too which pleasantly surprised me too. Mind you I'm using the idiot gauge which while isn't as accurate as an aftermarket gauge like an AutoMeter which displays the actual temp, is better than nothing and is at least a constant in my observations.

I started driving it around near my house, just in case anything went sideways. Temp was peak for the day at 106 so it was definitely toasty. Speeds varied but didn't exceed 45 and I had a few stop signs and lights to deal with and then did some slow (admittedly perhaps creepy) driving through some residential areas. Temperature barely increased, but did to the point it was noticeable and the needle was just above the horizontal/level position on the gauge.

At this point I'm thinking (with the exception of my botched fan install and the occasional noise) that I have it handled, but I had one final test in mind. I let it sit and idle for about 10 minutes or so while playing musical vehicles, etc. and that's when the "resting" temperature started to rise. It didn't technically overheat and exceed the normal range but was right up at the N/O which is significantly elevated.

I was disappointed and didn't think this was acceptable. I understand these engines "run hot" but with the work I've done I expected to be done with it after getting the OEM-style radiator in there (which fit the hoses I swapped over MUCH better than the Alloy works).

This leaves me thinking...water pump maybe? I'm curious what y'all think, it's literally the only thing (with the exception of the heater core/hoses) in the cooling system that hasn't been replaced and it's a straightforward enough job, I just wondering if I go through the hassle of it if it's going to result in lower operating temperatures...

Thanks all!

 

[RobbieD]

I'm hoping @Uncle Gump, @lil_Blue_Ford, @RobbieD and some of the other folks who have been REAL helpful can weigh in on this one...

I ordered a factory/OEM styled radiator (not Motorcraft) to see if there was going to be anything different from the Alloy Works one(s) that haven't been up to task seemingly. I was mostly concerned with the angle of the upper radiator outlet in particular.

Initially it didn't appear different to me which frankly got me a lil agitated. When I was begrudgingly in the process of packing it up to send it back to Parts Geek I noticed that it looked significantly thicker than the Alloy Works ones. Measuring confirmed that the Alloy Works were 1.75-inches thick, and the OEM-style was 2.25-inches. That massive difference got me thinking that was the reason why the cooling couldn't keep up.

So, along with a variety of hoses for my BII and later model 4.0 Exploders, a 180-degree thermostat and new radiator cap I decided to swap them out yesterday. I had to remove the universal fan shroud and bought an zip-tie style oil cooler installation kit to mount it to the new radiator...which I didn't get exactly right since the fan blades will now strike if I hit I hard enough bump but that's easy enough to rectify...

I expected it to run cooler with the new (lower) thermostat and it did. It took quite a bit longer for it to reach operating temp too which pleasantly surprised me too. Mind you I'm using the idiot gauge which while isn't as accurate as an aftermarket gauge like an AutoMeter which displays the actual temp, is better than nothing and is at least a constant in my observations.

I started driving it around near my house, just in case anything went sideways. Temp was peak for the day at 106 so it was definitely toasty. Speeds varied but didn't exceed 45 and I had a few stop signs and lights to deal with and then did some slow (admittedly perhaps creepy) driving through some residential areas. Temperature barely increased, but did to the point it was noticeable and the needle was just above the horizontal/level position on the gauge.

At this point I'm thinking (with the exception of my botched fan install and the occasional noise) that I have it handled, but I had one final test in mind. I let it sit and idle for about 10 minutes or so while playing musical vehicles, etc. and that's when the "resting" temperature started to rise. It didn't technically overheat and exceed the normal range but was right up at the N/O which is significantly elevated.

I was disappointed and didn't think this was acceptable. I understand these engines "run hot" but with the work I've done I expected to be done with it after getting the OEM-style radiator in there (which fit the hoses I swapped over MUCH better than the Alloy works).

This leaves me thinking...water pump maybe? I'm curious what y'all think, it's literally the only thing (with the exception of the heater core/hoses) in the cooling system that hasn't been replaced and it's a straightforward enough job, I just wondering if I go through the hassle of it if it's going to result in lower operating temperatures...

Thanks all!

I do think that that 2.25" OEM style radiator is your best choice, and it sounds like it's definitely taking you in the right direction.

Here's a question / suggestion: How well "sealed" is your radiator assembly?. Think of "assembly" as the core support, the radiator, the fan and the fan shroud, and how they all work together as a unit. When these trucks were equipped with A/C, Ford added plastic and foam sealing pieces at the factory (and you know that they wouldn't spend an extra penny unless it mattered).

The deal is, is to keep the fan from pulling (or pushing!) air from around the radiator, which reduces the air flow through the radiator. The sealing or blocking of any gaps makes more air go through the radiator, which helps with the cooling.

In @85_Ranger4x4 's epic build thread, this came up and there's some factory manual pages I posted there which might help you. See post #1859 (!), and I hope this link puts you close:
https://www.therangerstation.com/fo...-ranger-restomod.111591/page-124#post-1862268

I don't know (without going back over the thread) what you're running for a fan (stock or electric), but the basic premise is to get the maximum amount of your fan air flow through the radiator without it leaking around the radiator. Same principle applies to either fan type, and it's when the truck is stopped or at low speed where the fan performance really matters. At speed you're getting a much better air flow so any leakage doesn't matter as much.

You're close; just keep beatin' on it!

 

[Uncle Gump]

@RobbieD makes great points... and summed up very well what I would have said.

I went back to find out you have electric fan set up. Did you set it up to push or pull? And what oil cooler... engine... transmission? And if there is a large enough gap to get a cooler between the radiator and fan... chances are it too much gap unless the fan is shrouded tight to the radiator.

So many questions... pictures would be helpful.

 

[Peter Griffin]

@RobbieD, I previously ran an electric fan with the Alloy Works radiator that was NOT moving enough air to be up to task. It was fine earlier this year and it was actually running on the cooler side (needle slightly below horizontal) but as soon as the temps started climbing and I added the A/C to the mix, it was clearly becoming an issue...

Although Flex-a-Lite (who I previously had a HUGE issue with, but that's a whole other story...) makes higher output/CFM fans than the Chinesium one the Alloy Works came with, decided it was NOT worth the expense of upgrading the alternator and fan controller/wiring harness to try to deal with it...

It was after removing the e-fan and putting the stock one back on that I realized...there's no fan shroud to surround the fan to focus it's draw and at idle in particular, it's just slapping the air around inefficiently. The universal fan shroud I bought undoubtedly improved that, but not to extent that a factory shroud would.

I was unsuccessful in locating a replacement but I'll double my efforts in light of (1) your response and (2) seeing someone here recently have success in doing exactly that!

 

[Uncle Gump]

I guess I should've read deeper to see you replaced the efan.

 

[Peter Griffin]

...@UncleGump, with the exception of the universal fan shroud in place of the factory one; it's a factory setup. The A/C condensor is in front of the radiator, which has a built in transmission cooler and the oil cooler is in front of that. You can see in the pictures that the universal shroud does NOT surround the entire fan however...

*edit; my A/C tech/mechanic said that the stock fan/clutch are definitely working properly; it seemed that way to me but I did ask since he was working on it.

 

[Uncle Gump]

I had to go back a read again...

So the fan hits the shroud and not the cooler.

Yeah... you need a shroud that fits and does more of what a shroud is suppose to do.

 

[RobbieD]

@RobbieD, I previously ran an electric fan with the Alloy Works radiator that was NOT moving enough air to be up to task. It was fine earlier this year and it was actually running on the cooler side (needle slightly below horizontal) but as soon as the temps started climbing and I added the A/C to the mix, it was clearly becoming an issue...

Although Flex-a-Lite (who I previously had a HUGE issue with, but that's a whole other story...) makes higher output/CFM fans than the Chinesium one the Alloy Works came with, decided it was NOT worth the expense of upgrading the alternator and fan controller/wiring harness to try to deal with it...

It was after removing the e-fan and putting the stock one back on that I realized...there's no fan shroud to surround the fan to focus it's draw and at idle in particular, it's just slapping the air around inefficiently. The universal fan shroud I bought undoubtedly improved that, but not to extent that a factory shroud would.

I was unsuccessful in locating a replacement but I'll double my efforts in light of (1) your response and (2) seeing someone here recently have success in doing exactly that!

Agree 100% with @Uncle Gump.

Honestly, I think that a factory shroud would make a big difference. In addition to "hugging" the fan blades better, the radiator side will enclose, and thus pull air through, the whole cooling core. The setup you have now is only pulling airflow in a round spot in the middle. At speed you're OK, but suffering otherwise.

I understand the benefits of electric fans, but personally I prefer the factory stock setup.

You're running a 2.9 in yours, right? The best thing I did to my '90 B2 to keep the motor happy was add the big Explorer radiator.

 

[Peter Griffin]

I had to go back a read again...

So the fan hits the shroud and not the cooler.

Yeah... you need a shroud that fits and does more of what a shroud is suppose to do.

Yeah it's hard to keep up with all my drama...I get it!

The right side of the shroud is ever so slightly too close to the fan, so I need to cut the tie and move it slightly outboard to clear it. It's worth noting that the shroud can only attach in 3 of 4 mounting points because it's too tight otherwise to clear it.

I posted a Wanted ad for an OEM shroud...sounds like that would fix it for sure; the search continues!

That being said I absolutely LOVE it here. This is the first time I've undertaken a build of this magnitude, which, admittedly, is pretty mild; no engine/axle(s) swap, etc. but I've had every question I've asked, answered and several gentlemen come to my rescue with necessary parts at NO cost, just covering shipping...?...! That's AWESOME! I'm hardly frustrated, especially considering the assistance I'm getting from y'all...

*edit, yes, it's the factory 2.9. 87+K original miles; leak free and running pretty strong actually...

Now I'm not sure if I should swap out this radiator for a big Explorer radiator...ugh...third time is a charm? Maybe try the shroud first...

 

[Peter Griffin]

*additional edit after reading the link that @RobbieD posted; I do NOT have the foam spacers between the condenser and the radiator. They'd be easy enough to fab up if I knew the dimensions of the original ones, I'll just grab some material from Amazon, Michael's or whatever...

 

[lil_Blue_Ford]

So I’ll throw a few things out…

I definitely agree with a lot of what’s already been mentioned. I have a problem that I haven’t really solved with my choptop with the fan surround. With a 2” body lift and a redneck intake tube, a stock fan shroud doesn’t fit. Not even a little. I didn’t really worry much about it but…

Anyway, my F-150, when I set it up for plowing snow, I did a new water pump, 180* thermostat, mixed the coolant 60/40, added a super-wetter, and tilted the radiator out about 3/8” with spacers and longer top bolts. It actually wouldn’t warm up in the winter without the plow on like that, or I had to block part of the radiator.

 

[Peter Griffin]

In my Wanted post @PetroleumJunkie412 suggested a MB C230 e-fan:

Delete - '88 BII OEM fan shroud

Readers Digest story is it's hot AF here in extreme SW AZ 🥵 and when I bought my truck earlier this year it had no shroud. I have an universal one in place now but it does not fully enclose the fan like the OEM shroud does which is causing me issues at extended idle. If you wanna read about the...

www.therangerstation.com

That MIGHT be doable, @ 6K CFM I'm certain it's up to the task, depending on which one I'd need to buy (it's a pusher apparently) I'd need a proper wiring harness and controller. I'm not adverse to going back to an e-fan and I'm not running anything demanding on my build with the exception of a 8-inch powered sub and have arguably reduced total draw by converting all lighting to LED (including the headlights), so I'm not terrified of a 25/30A e-fan, just of not keeping my engine as cool as possible when it's a million out!

 

[RobbieD]

*additional edit after reading the link that @RobbieD posted; I do NOT have the foam spacers between the condenser and the radiator. They'd be easy enough to fab up if I knew the dimensions of the original ones, I'll just grab some material from Amazon, Michael's or whatever...

Fabbing some sealing for better air flow is definitely a DIY project, and worth the trouble.

Sheet rubber is useful, and for any foam I suggest closed-cell foam, like the pipe insulator sleeves are made of (in fact, these work well for the mentioned foam spacers). The point with the closed-cell foam is avoiding something that's absorbent like sponge, which will trap and hold water.

You're on a roll now; you'll be cool before you know it.

Just don't forget the sunglasses. Can't be cool without shades.

 

[85_Ranger4x4]

Now I'm not sure if I should swap out this radiator for a big Explorer radiator...ugh...third time is a charm? Maybe try the shroud first...

For added entertainment value the Explorer shroud has different spacing on the mounting tabs on the bottom than the single row radiators.

*additional edit after reading the link that @RobbieD posted; I do NOT have the foam spacers between the condenser and the radiator. They'd be easy enough to fab up if I knew the dimensions of the original ones, I'll just grab some material from Amazon, Michael's or whatever...

It isn't really anything special, maybe 1/2" thick. Mine is like 30 years old so it isn't all that resilient but it may have been firmer back in the day.



The big rubber seals at the top and the bottom seams are more special and specific to their locations.

The condenser to to radiator seals were a big deal for me because I have pusher fans mounted in front of the condenser so just putzing around the air was reluctant to go thru the rad. With your mechanical fan it would be less of an issue, how much less I can't say.

IMO it should cool like it is especially if you get a factory shroud.

 

[Peter Griffin]

Thanks @85_Ranger4x4 for weighing in, I very much appreciate it!

@lil_Blue_Ford mentioned that the body lift on his prevented the use of the shroud, which got me thinking that may be why mine doesn't have one to begin with...? I have a gentleman posting in my Wanted thread that he has a couple available and trying to work something out with him...

In the interim, I think the foam spacers are a no-brainer. I did already add Royal Purple Ice as a "water wetter" and I definitely noticed that it had a measurable decrease in temp.

Just looking at it I can see that there's WAY more space between the universal shroud and the fan blades at the top than needs to be. I'm going to cut the zip ties and reinstall the shroud and see if that helps (along with the foam spacers). The other idea I had was to buy another universal shroud and mount it upside down to enclose the entire fan. At the bottom, the fan is about even with the bottom of the radiator. Also, it looks like the shroud almost completely surrounds the fan, there's only about 1/8ths of an inch where the fan is outside the edge of the shroud...

The other idea I had was to get the OEM shroud; mock it up so it properly surrounds the fan, and to mount it drill holes in it and use a zip tie kit like I used on the universal shroud to mount that...

If I can get more information on the MB C230 e-fan that @PetroleumJunkie412 mentioned, that may be worth the old college try. I would need a fan controller and wiring kit in addition to the fan, so it wouldn't be cheap but 6K CFM REALLY got my attention! It looks like there's only an inch or so between the front of the radiator and the backside of the A/C condenser so my concern there is there's enough room for the fan to fit!

I said from the outset that keeping the vehicle cool and its occupants were a priority and to put that in perspective it's gonna be 112 here today, and we're still not near peak summer temps as I've already mentioned...!