Nashville TJ's Build - Continued

[NashvilleTJ]

Well, I've learned something about the rig while running without a thermostat. I've got a cooling problem.

The Jeep has always run in the low 200's, occasionally creeping up to 210 or so. And guess what, without a thermostat is does the exact same thing. I run a 180 degree thermostat, so once it opens, it has just been staying open. This tells me that the cooling system is not able to keep it under 180, allowing the thermostat to keep it up at operating temp.

Frankly, I always assumed I had installed a mislabeled, stock 203 degree thermostat - which seemed to make sense given the temps I was seeing.

When I built the Hemi, it's was running hot with the original fan I bought, so I replaced it with the most powerful fan I could find at the time - one that was still slim enough to fit between the engine and the radiator. What fit the bill at the time was a Derale 17", 23.5 amp fan. At the time SPAL had more powerful fans available, but all were too deep at about 4.5".

That's the original on the left, the Derale on the right.

In front of the fan is the radiator, A/C condenser, and radiators for power steering and the tranny which together cover the entire opening. I now think that the 23.5 amp fan is not enough for that setup.

After some research, I found that SPAL now makes brushless fans. Their big boy now is a 16", 2450 cfm fan that pulls almost 40 amps. I learned before never to pay attention to the cfm as it can be misleading. The real measure is the amp draw.

This is the SPAL fan - now I just need to find one. No success so far.

https://www.spalautomotive.it/brushl...06p-103a/36707

 

[someguysjeep]

most options pop up from UK, France and Italy.
that world map, bottom left shows 1in Canada? if so that'd probably be the easiest.

they carry some maybe they can locate ya 1.
https://www.kartek.com/

 

[Wildman]

Well, I've learned something about the rig while running without a thermostat. I've got a cooling problem.

The Jeep has always run in the low 200's, occasionally creeping up to 210 or so. And guess what, without a thermostat is does the exact same thing. I run a 180 degree thermostat, so once it opens, it has just been staying open. This tells me that the cooling system is not able to keep it under 180, allowing the thermostat to keep it up at operating temp.

Frankly, I always assumed I had installed a mislabeled, stock 203 degree thermostat - which seemed to make sense given the temps I was seeing.

When I built the Hemi, it's was running hot with the original fan I bought, so I replaced it with the most powerful fan I could find at the time - one that was still slim enough to fit between the engine and the radiator. What fit the bill at the time was a Derale 17", 23.5 amp fan. At the time SPAL had more powerful fans available, but all were too deep at about 4.5".

That's the original on the left, the Derale on the right.

View attachment 281046

In front of the fan is the radiator, A/C condenser, and radiators for power steering and the tranny which together cover the entire opening. I now think that the 23.5 amp fan is not enough for that setup.

After some research, I found that SPAL now makes brushless fans. Their big boy now is a 16", 2450 cfm fan that pulls almost 40 amps. I learned before never to pay attention to the cfm as it can be misleading. The real measure is the amp draw.

This is the SPAL fan - now I just need to find one. No success so far.

https://www.spalautomotive.it/brushl...06p-103a/36707

Why do you want it running cooler? I don't know about the Hemi but the Magnum V-8 needs to be running at 210* to run properly. When you use the cooler thermostats in them it messes up the tune.

Do you have it tuned to use the lower coolant temps?
I have the Black Magic fan which use to move the most air but it's a large fan too.

EDIT:
Have you looked at any OEM fans like the Ford Taurus 2 speed or the Lincoln? They are suppose to move a ton of air. And if you can make the dual speed thing work they are great. I had one on my Jeep when I still had the 4 cyl.

 

[NashvilleTJ]

Why do you want it running cooler? I don't know about the Hemi but the Magnum V-8 needs to be running at 210* to run properly. When you use the cooler thermostats in them it messes up the tune.

Do you have it tuned to use the lower coolant temps?
I have the Black Magic fan which use to move the most air but it's a large fan too.

EDIT:
Have you looked at any OEM fans like the Ford Taurus 2 speed or the Lincoln? They are suppose to move a ton of air. And if you can make the dual speed thing work they are great. I had one on my Jeep when I still had the 4 cyl.

The issue is not so much getting it running cooler, but with it running 200-210 with no thermostat, it's on the edge. Without the thermo it should be running much cooler than that. It was tuned with a 180 in there.

The Derale I have is a 2 speed - but I only run it on blast. With what I know now wiring it up for two speeds would have definitely been a waste of wire. The SPAL is also a two speed, and if I go that route I may take the time to go two speed.

My issue is that I only have about 3 1/2" of clearance, so finding enough power in that size has been a challenge.

 

[NashvilleTJ]

most options pop up from UK, France and Italy.
that world map, bottom left shows 1in Canada? if so that'd probably be the easiest.

they carry some maybe they can locate ya 1.
https://www.kartek.com/

Thanks. I actually found a custom radiator place up in New York which has them on their site. I'll call them tomorrow and see if they have one in stock. They look to be about $650 with a wiring kit.

 

[Wildman]

The issue is not so much getting it running cooler, but with it running 200-210 with no thermostat, it's on the edge. Without the thermo it should be running much cooler than that. It was tuned with a 180 in there.

The Derale I have is a 2 speed - but I only run it on blast. With what I know now wiring it up for two speeds would have definitely been a waste of wire. The SPAL is also a two speed, and if I go that route I may take the time to go two speed.

My issue is that I only have about 3 1/2" of clearance, so finding enough power in that size has been a challenge.

OK.
I just know this had been a talked about subject many times on the Dodge forums just like here about the idea that just throwing in a cooler thermostat somehow will make more power. I was fairly sure you weren't doing that but still had to ask.

The SPAL fan controller I have allows you to bring it on at 50% at a lower temp and then 100% at the higher temp. You don't have to have a 2 speed fan with it.

The Taurus fan being 2 speed was really nice with the 4 cyl. It's been too long since I did it buy I got a controller for it off Ebay.

Yes your size is a serious limiter on what can fit. Can you explain a little more about the CFM vs Amp and how this works?

This Flex-a-Lite fan moves 2500 CRM by their rating but only draws 18.5 amps.

https://www.flex-a-lite.com/electri...y-fans/16-inch-loboy-electric-fan-puller.html
This is the fan I have on my brass radiator.

https://www.flex-a-lite.com/electri...electric-fan-for-1987-2006-jeep-wrangler.html
I have a aluminum radiator but it's a Ebay POS but it does have a SPAL fan on it.

 

[NashvilleTJ]

...

Yes your size is a serious limiter on what can fit. Can you explain a little more about the CFM vs Amp and how this works?

This Flex-a-Lite fan moves 2500 CRM by their rating but only draws 18.5 amps.

https://www.flex-a-lite.com/electri...y-fans/16-inch-loboy-electric-fan-puller.html
This is the fan I have on my brass radiator.

https://www.flex-a-lite.com/electri...electric-fan-for-1987-2006-jeep-wrangler.html
I have a aluminum radiator but it's a Ebay POS but it does have a SPAL fan on it.

As I understand it....

The CFM ratings on most fans are worthless without context. That first fan I had was rated at something like 2700 CFM - and I thought man, that's plenty, and among the highest rated out there. The rub is this - if you measure CFM when the fan is in open air - 0 static pressure - it's easy to move that much air. Increase the static pressure - i.e. put it in front of a radiator - and it becomes more and more difficult to move that much air. Add a condenser, more static pressure. Add additional coolers, more fins, thicker radiator - even more static pressure. As this happens, the load on the motor increases and if it does not have enough power, the CFM the fan can move drops off very quickly as that static pressure increases.

As static pressure increases, more and more power is required to keep up the CFM. That 2700 CFM fan which I originally purchased was labeled 120 watts - that's 10 amps at 12 volts (amps = watts / voltage). Just like any power tool, the amperage it is able to pull and turn into energy is the best gage of power. That's why with electric motors you pay attention to amps, not horsepower.

Quality fans - such as SPAL, Derale, etc., publish graphs which show CFM performance as static pressure increases. The tech sheet on the SPAL fan url I posted above has such a graph. Note that this 500 watt fan is only rated at 2450 cfm - but moves 4000 cfm at 0 static pressure. After some research I discovered that the first fan of mine was rated at 2700 cfm - at 0 static pressure. And that 10 amp motor did not have the power to move anywhere near that much air in front of a radiator, with a condenser, and additional coolers...

And that's the story - pulling 2700 CFM through a radiator takes much more power than pulling 2700 CFM in open air. So the amperage rating of the motor is everything in terms of how much air the fan will pull through a radiator. The higher the better.

So CFM sells fans, amps win races (or something like that...).

 

[Wildman]

Thanks that helps me understand how this works and is rated.
I don't think the Black Magic fan I have shows a graph like that. I'll have to do some more looking.

 

[NashvilleTJ]

An additional thought on my comment above about HP vs. Amps. I have a shop vac which is rated at 6 HP. 6 HP is about 4400 watts. In order for an electric motor to generate 4400 watts at 120 volts, it would require over 36 amps - but this shop vac is designed to run without blowing a 15 amp fuse on a 120 volt circuit. How does that work? I do not understand how they come up with HP numbers on things like this shop vac.

 

[NashvilleTJ]

Today I was able to find the 500W 16" SPAL fan I was searching for at a place up in New York called Wizard Cooling. I called them and talked through what I needed, and they have a unit in stock along with a wiring package. So I placed the order, cried once, and I should see it in about a week.

The only down side is that they would only sell the fan as part of a package with an aluminum shroud kit - which I do not need. Wizard was the only place I found that had one in stock, so I had to take that lump. Oh well, some additional aluminum for the collection...

 

[NashvilleTJ]

I was out of town most of last week, but when I returned - this was waiting for me:

The Derale Fan was listed as a 17" model, and the 500 Watt Spal was a 16", so I was thinking I was giving up a little fan surface area for the extra power. Turns out the Spal fan is actually bigger. The Derale measures 17" to the outside diameter of its shroud. The Spal actually measures the fan:

The Specs I reviewed when I ordered the Spal made it look like the hole diameter on the current shroud would likely work with just a little trimming - but it fit perfectly. All I had to do was to punch a few holes for the mounting bolts, plug the original mounting holes, and just like that it was attached.

Man - Sunshine and rainbows!

 

[NashvilleTJ]

And so without too much work at all the new 16" (actual), 500 watt, crazy powerful fan was installed.

The wiring for this brushless fan is completely different than my old setup. The brushless will not run off a typical relay setup - it requires a signal across a control wire to the fan to operate it - so I was thinking my challenge with this whole project was going to be the wiring - since I like running everything through the PDC.

The signal which actuates the variable speed fan is generated by the temp sensor - which you can see installed at the top left of the radiator. There is also a separate override circuit which triggers the fan to run at full speed - also by generating a signal down the control wire. It's actually pretty slick.

 

[NashvilleTJ]

So with the fan installed, once again into the breach.

I pulled apart the PDC (I've been in here many, many times - it's like visiting an old friend), and wired in a 10gauge fused circuit to throw all that power directly to the fan. No relay needed here since the fan controller handles all the switching.

Before I got too deep into the wiring I thought it would be a good idea to test the fan to make sure it actually worked. So I made a few temporary connections for the controller and fired it up.

Once you generate the signal down the control wire, it takes a second or two for the fan to start spinning up, and then slowly builds up to maximum speed to avoid a huge current draw.

And man oh man does this thing move some air! The most air I've ever seen an electric fan move! A crazy amount of air!

A crazy amount of air pushing right into the radiator.

Yup - backwards.

Oh crap...

 

[Wildman]

We're all backwards now and then.

 

[NashvilleTJ]

Oh man - looking at all the laughing emoji’s at my dilemma - the compassion in this crowd is overwhelming!

 

[Wildman]

Oh man - looking at all the laughing emoji’s at my dilemma - the compassion in this crowd is overwhelming!

It's laughing with LOVE brother... We all feel your pain.

 

[NashvilleTJ]

I went back and checked the technical specs on the fan that I had ordered. I had spent so much time reviewing the size and performance specs to make sure it would work - that I completely missed the big red arrow showing the airflow direction. Oh yeah, I got just what I ordered.

So I called up the folks at Wizard Cooling where I bought the fan and told them I had ordered the wrong fan. I'd ordered a pusher, and I need a puller. Well, there is only one version of this fan. There is a Spal brushless puller, but it is only 300 watts.

I was speaking with Scott, the owner of the place - and he was more than helpful. I sent him a picture of the install - and he immediately told me I had mounted it backwards. These Spal units do not mount like a typical electric fan, but rather are made to sit down flush inside the shroud. Scott told me they could custom build a shroud for my radiator for $180 (quite reasonable) but it would take two weeks.

So my easy fan install turned into a custom shroud project. And after some thought, I came up with a plan. I could use my existing shroud, couple it with a few of the pieces from the shroud kit which came with the fan, and prolly do it in less than two weeks...

First up, I did what I thought I had avoided - enlarging the hole in the existing shroud to allow the Spal to sit down inside. After some marking and quick work with the grinder, that was done.

Next, out came the heavy duty power tools. On the band saw I trimmed the flanges from the original shroud.

And, it fits.

Then it was a matter of completing the box. The shroud kit came with aluminum L angle which would work well for the sides.

 

[NashvilleTJ]

To attached to shroud face to the new sides, I marked and drilled holes around the perimeter of the face to accept some small stainless screws.

Then, back to the bandsaw to trim the top and bottom of box. I always use soap on my blades when cutting aluminum.

The flanges would allow the shroud to attach to the radiator in the same manner as the original shallow shroud.

 

[NashvilleTJ]

The sides of the box do not require a flange, so I cut those off on the band saw. The top and bottom of the box flare out just a bit, so the sides had to be angled to fit properly. I marked the angle on the blank, and added a 1/2" to allow for a flange.

After cutting the sides to length, it was over to the press brake to bend the flanges.

A few screws later, and I had a 2 1/2" deep shroud.

And wadda ya know - it fits.
Attached Thumbnails

 

[NashvilleTJ]

And here it is installed. I'm pretty happy with how it turned out - although I was regretting my inability to TIG weld aluminum...

Then I went back to what I thought was going to be the most time consuming part of the project - finishing the wiring. In the cab, I have both an override switch which turns on the fan regardless of the temperature, and also a momentary interrupt switch which turns off the fan for water crossings, etc. I was able to wire those in to work properly.

And it runs. It draws a bit over 29 amps - a bit lower than I expected.

Although I did test the Derale 23.5 Amp rated fan before I pulled it - and it was only drawing 18 amps. So, nearly double the power.