A Tale of Upper Radiator Hoses & Fans

[Glass Pony]

The shroud is a WH steel shroud which I think was made to factory specs.
http://www.wildhorses4x4.com/product/Fan_Shroud_V8_only

The fan spacer is 3/4". I actually cut off an inch or so of the hose where it enters the upper radiator or the bend would have been back by the power steering pump.

 

[jckkys]

A quick glance at your photo in post #1 and Glass Pony's photo in post #20 reveals your whole problem. The correct Dayco hose clears the fan easily and your silicone hose with several inches missing on the radiator end is hit by the fan. Who cut it off? Was it defective? I have no idea. The obvious fact that it's missing, remains. A new hose is only about 15 bucks. Give it a try. The rubber ones last about 20 yrs. As I said before, the 3/4" OE spacer will keep the OE fan away from the shroud. If you get the 7 blade OE fan, it works with that too.

 

[DaveLev]

To be clear, I never cut it off, and it matches the length of the other two I have tried exactly (both returned). Notice that mine is more 'z' shaped, and his has an extra bend in it that mine does not. It is clear that his is longer. Will order that and check it out.

My last upper radiator hose burst off the thermostat housing, which is why I went for silicone (and to eliminate guessing what else could be causing my prior overheating problems).

 

[lonesouth]

don't use PVC to splice radiator hose...sayin...

 

[75junebug]

I had to trim the thermostat housing side of the hose about an inch to keep the fan blades out of my upper hose....

 

[DaveLev]

75junebug, which hose did you buy that required you to trim? You raise a good point - I never trimmed mine and could it be that is the issue? Hmmm.

I will be ordering the recommended hose above at some point (rubber) to replace the silicone. Drove today in 100 degree sunlight going 90 MPH at 210 degrees on the gauge and it didn't pop off or burst or rub, but again, look at how I have it barely hanging on in the photo above. Cheap insurance to replace it. Will do that when I do the dash/heater core next week (knock on wood).

 

[75junebug]

Dave, the hose was whatever Gates brand from Oriellys that the book recommmended for a 75 Bronco with 302 V 8.....This gets me to thinking......I havnt changed out hoses since 2005 when I put in the 351...... regardless of the 351 deck height difference, I had to trim the hose for the 302 back in 2002 to keep it out of the fan as well.

 

[lonesouth]

Here is another option

http://classicbroncos.com/forums/showpost.php?p=2286119&postcount=22

 

[75junebug]

upper radiator hose

Here are a few bad pics from a couple years back....the radiator side of the upper hose is inserted just over the barb of the radiator inlet just enough for the clamp to be set.

 

[AZ73]

An alternative is One of Nick's Trix tricks. Look under the hood of Tupe. While your set-up isn't the same, splicing a piece of metal tube into hose sections would work.


http://www.nickstrix.com/builds/tupe/tupe.html

 

[DaveLev]

75junebug - I don't have a 302 with serpentine belts, and my thermostat housing does not point straight up, so your first pix aren't an option. The pictures where the hose is barely on the barb is like my setup on the radiator side, but your hose is unique in that it curves over the accessories a bit. What hose number is that? I also tried the O'Reily hose for the year and model you recommended, but that is the exact same size as the silicone hose I have now and the other 3 hoses I've tried (all different manufacturers). I wonder if my stock radiator is somehow thinner than others. Will measure that and report back.

Either way, I picked up a 1 3/4" hayden fan spacer today, and will replace the 1" I have now. I know this may require trimming up the fan shroud, but should not be too close to the radiator, so it should work. With the shroud off I can see where my 18" 7 blade fan is rubbing better, too.

This sure is a lot of work to just get the engine cool, but after dropping $900 on rebuilding the heads and valves, what more can I do. Stuck with this money pit for now.

For those of you who may be asking, "why?", it is simply because of the 11th commandment: Happy Wife, Happy Life. This is her rig.

 

[75junebug]

DaveLev, those were not my pics of a serp system. The themostat housing that points straight up thats in those pics is a standard housing found on most 5.0 EFI engines if I an not mistaken... That being said, I have had the original radiator, a 4 core WH copper radiator and now back to a factory spec replacement copper radiator....I didnt notice enough difference in widths to really affect the fan/radiator spacing....What I did do, and did not mention before, is due to the 2" BL, I did rig a homemade means of lowering the fan shroud 2" instead of trying to lower the entire radiator...Not sure if it affects anything though..Not sure how big my fan spacer is, but the fan does sit perfectly in the shroud, and if I remember right, I have about 1-1/2" of space between the fan and radiator....just as a precaution, I also have one of those weber grill looking radiator protector things....I'm a big fan of those....
Basically I believe(my opinion only, take it for what its worth) the fan should extend into the shroud only about 1/4" to 1/2". Get a good quality high flow water pump. I'm running a stay cool aluminum, with anticavitation vanes built in. I run a 190degree thermostat.....3 core copper radiator(copper or brass, whatever) I run 50/50 mix of good quality antifreeze. In addition to this, and due to the cooling issues I had when I first put in the 351W, I also drilled and tapped the rear coolant bungs for 3/8" npt, I used to have a crossover that tied both back to the return heater hose, now i just have the pass side T'ed in to the return heater hose with a valve.....this allows the air that sometimes get trapped in the rear upper intake cooling passages to be "burped out".
South Texas heat, long idles in traffic, trips to Moab, and Colorado have been overheat free since these mods.....That being said, I just got my parts in today to install a fan clutch to cut down on some of the noise....I'll be posting up post install as it develops.
Jaguar fan clutch with a 69 Bronco fan.....I'm curious to see if it will move enough air...

 

[DaveLev]

I do have the high volume pump. I just read in a thread elsewhere that someone's radiator was too narrow by 3/4 inches, about what I'm experiencing at least. Let me know how that clutch fan goes. I run an edlebrock high volume water pump, FYI, after negative experience with reman one (and rebuilding entire top end). Still 3 core copper, good 50/50 mix myself, no body lift, no thermostat (which is working great by the way).

 

[DaveLev]

Here's the promised measurements taken from the front of the vehicle towards the water pump.

Starting at the back of the core support to the front of the radiator is 1.25"

The depth of the radiator is 2.25".

The distance from the back of the core support to the upper bung where it attaches to the radiator is around 3.45".

The distance between the back of the radiator and the fan blades is 1.875".

The fan spacer is 1" today. I will be changing to 1.75" spacer, which will bring the gap between the radiator and the blades to about 1.125".

This is a lot of work to get a fan to stop rubbing my upper radiator hose, which we have measured numerous times in several ways.

Open to suggestions.

 

[DaveLev]

Here's the long awaited update with pictures (for those of you who are still following along):

Overview of 7 blade fan with radiator out:

7 blade fan showing that it sits about 1/2" from upper hose with radiator out:

The 5 blade stock fan sits 1.25" from upper hose with radiator out:

The lower hose with radiator out sits 3" from the core support:

But the upper hose sits 5" from the core support!:

The stock shroud - is this the right one?

The fan shroud is about 2.125" deep:

The fan shroud opening is about 20" wide:

The 7 blade fan hitting stock fan shroud:

The 7 blade fan showing signs of scraping on the trailing edge:

The 5 blade fan with 1" spacer:

The 5 blade fan 'depth' is about 1.5" deep total:

The 7 blade fan 'depth' is about 2.25" total (.75" deeper):

The 7 blade fan width is not 17"...appears to be 19.5" wide:

The 5 blade stock fan width is about 18" on the nose:

The stock fan back on showing tons of clearance to the upper radiator hose (without radiator installed):

Different overview angle:


The somewhat ugly fix to my upper hose problem that I came up with:

The radiator shop added a 1.75" section to the top and pressure tested it for $38. It is installed and has not leaked.

But, the 5 blade fan sucks compared the 7 blade at keeping the system cool during my brief 60 minute test (see other thread on this). Therefore, I will be swapping the fans back or finding another option or something new or fun.

When I installed the radiator, shroud and hoses, the upper radiator hose goes until about the 1.125" mark on the new upper bung, so you don't see the ugly stuff at all - the hose slides over about 2" just fine and the fan does not hit.

 

[SeanT4x4]

Is the silicone hose worth the trouble of radiator modification? My fan was pretty close to my upper hose as well. Thanks to this thread I ordered the Dayco E70627 from summit and I have tons of room now.

 

[toddz69]

Is the silicone hose worth the trouble of radiator modification? My fan was pretty close to my upper hose as well. Thanks to this thread I ordered the Dayco E70627 from summit and I have tons of room now.

Absolutely not in my opinion.

Todd Z.

 

[savage]

Is that silicone hose that important, that you just don't want to get a hose that would fit better. It seems to be a lot of work to extend the upper radiator connection, and can you trust the fix, from leaking or cracking, with more leverage on that part of the radiator, with it extended. Just my 2 cents.

 

[DaveLev]

I ordered the Dayco radiator hose that crossed reference to a gates hose or something. It was the same hose I've tried several times. If you're following the posts, you'll see that there was about a 2 1/2 inch gap between the upper hose and the radiator. Even though I could make the hose reach the radiator without modifying The radiator, I could not find one that would work with the oversized fan with seven blades that makes a world of difference in keeping the bronco cool. The benefit to the silicone hose that I can say with confidence is the ability to remove it and reinstall it, which I have done for or five times now. I would not have considered these hoses but it was one additional thing to try to make sure the stock hoses weren't collapsing or affecting the ability for the bronco to stay cool. If you're following this or some of my other threads, you will know that at one point A rubber radiator hose actually blew off the thermostat housing. Since I switched to the silicone, that has not happened. That experience really frightened me, as I had no hood and was going down the freeway at 60 miles an hour when it happened. For me, buying the silicone hose kit was cheap insurance.

 

[savage]

I ordered the Dayco radiator hose that crossed reference to a gates hose or something. It was the same hose I've tried several times. If you're following the posts, you'll see that there was about a 2 1/2 inch gap between the upper hose and the radiator. Even though I could make the hose reach the radiator without modifying The radiator, I could not find one that would work with the oversized fan with seven blades that makes a world of difference in keeping the bronco cool. The benefit to the silicone hose that I can say with confidence is the ability to remove it and reinstall it, which I have done for or five times now. I would not have considered these hoses but it was one additional thing to try to make sure the stock hoses weren't collapsing or affecting the ability for the bronco to stay cool. If you're following this or some of my other threads, you will know that at one point A rubber radiator hose actually blew off the thermostat housing. Since I switched to the silicone, that has not happened. That experience really frightened me, as I had no hood and was going down the freeway at 60 miles an hour when it happened. For me, buying the silicone hose kit was cheap insurance.

I have been reading this thread and was wondering why you didn't look at changing the thermostat housing to a 90 and just cutting your silicone hose and put the barb connecter on it , then you could have turned the hose any way you wanted to, and still had the hose you wanted. I had the same thermostat housing that made the hose to close to my fan, so I did it the way some of the guys suggested , and it work great.