Heat torture cooling system test... Exploder mech vrs Tauras electric fans...

nvrstuk · Aug 10, 2017

Update on fan and pulley

nvrstuk · Aug 10, 2017

Here's some good info I thought might be useful if you are reading about this fan combination ... I'll try to link the write up to it also ..

This was done by another CB guy who had a wind flow gauge to measure the differences... pretty interesting results

"Six blade 17 in. stock fan, stock pulley - 492 ft/min
Six blade 17 in. nylon flex fan from Summit, stock pulley - 708 ft/min
Seven blade 18 in. stock flex fan, 5.4in pulley - 846 ft/min

So, I got a 72% increase at idle. I'll see what that does for my A/C head pressure and engine temps."

pbwcr · Aug 10, 2017

The 11 blade 18" Explorer fan should out perform the ones mentioned.

nvrstuk · Aug 10, 2017

That's probably true but we have no way to measure the air flow with the same criteria...same Bronco, same shroud, same pulley sizes, same radiator, etc...

Wish we could but that would require changing over to the serp setup just for the test...

DirtDonk · Aug 10, 2017

We should all e-mail "Engine Masters" on YouTube or TV or wherever you view them and have them do a back-to-back comparo of "our" fans, along with this time using an anemometer to gauge air flow. Their test only tested the power output of the engine with each fan.
Since they've already done their multi-fan shootout though, so might not be interested.

Did you all see it yet? Episode 20 https://www.youtube.com/watch?v=ZXdLgaFXZzs
The one thing they missed was that the unshrouded fan looses less power because it's pulling less air through the radiator.
It might have "more air to bite" as they said, but it's not pulling it through. It's simply sluffing it off the tips of the blades and letting it go hither and yon instead of focusing it over the blades.
At least that's my non-engineer take on it.

So that's our argument to them for doing it again. Different fans and this time using an anemometer.
And of course, using our choices of fans. The Taurus, the Explorer, and the two factory fans. Or any others we want.
Let's get an e-mail campaign going!

Paul

pbwcr · Aug 11, 2017

Yes, real testing with a common EB setup would be good. What we know from other vehicle tests that the shroud is important. The plastic shroud is better than the tin ones due to the internal aero shape. Then we have to deal with the depth of the fan into the shroud. * We also know that the tip shape on the 11 blade is better than the straight blade on the 10 blade. No metal fans matched the 11 blade. I guess that Ford discovered that a long time ago.
Then most important is how the shroud fits the rad. Gaps at the sides, bottom, and top will defeat getting good flow data.
So far the plastic 11 blade wins all flow test I have seen when tested with all other variables being the constant. ((Caution on the plastic fans. They are good when new, but the Junk yard ones are pretty crappy due to a long life which results in cracking)). New Motorcraft fans are widely available for less than $50.
* Good luck finding a shroud that fits to my satisfaction. All the installs I have done have a very custom plastic shroud that started with one that was close then cut up & fiber-glassed to meet my criteria noted above.
PaulW

pbwcr · Aug 11, 2017

DirtDonk said:
Did you all see it yet? Episode 20 https://www.youtube.com/watch?v=ZXdLgaFXZzs

Paul

=== ===
That engine master testing is off topic. Nothing is mentioned about cooling.
Of course we all know that fans are for cooling, not low horsepower loss.
The OEMs have migrated to electric fans to conserve horsepower and increase gas mileage. But us commoners do not have the ability to size and have custom Efans made.
So to keep the engine cool we have found that a good OEM mechanical clutch fan is our choice. We are willing to give up horsepower to keep the engine in the proper temperature range, and we live with the horsepower loss.
Regarding horsepower loss - when that clutch fan engages the horsepower loss is very big. And probably greater than any other fans they tested. Engine masters ignore that.
PaulW

toddz69 · Aug 11, 2017

pbwcr said:
Yes, real testing with a common EB setup would be good. What we know from other vehicle tests that the shroud is important. The plastic shroud is better than the tin ones due to the internal aero shape. Then we have to deal with the depth of the fan into the shroud. * We also know that the tip shape on the 11 blade is better than the straight blade on the 10 blade. No metal fans matched the 11 blade. I guess that Ford discovered that a long time ago.
Then most important is how the shroud fits the rad. Gaps at the sides, bottom, and top will defeat getting good flow data.
So far the plastic 11 blade wins all flow test I have seen when tested with all other variables being the constant. ((Caution on the plastic fans. They are good when new, but the Junk yard ones are pretty crappy due to a long life which results in cracking)). New Motorcraft fans are widely available for less than $50.
* Good luck finding a shroud that fits to my satisfaction. All the installs I have done have a very custom plastic shroud that started with one that was close then cut up & fiber-glassed to meet my criteria noted above.
PaulW

The Ron Davis aluminum full circle one is the best one, in my opinion, of rate Explorer conversion, although it's shape probably isn't as aero as you'd like it to be.

Todd Z.

ntsqd · Aug 12, 2017

This is the method that I intend to use to build the shroud once I have a decent size radiator installed:

https://forum.ih8mud.com/threads/homemade-fan-shroud.597038/

I've seen several done like this and they end up much more aero than a fabricated metal shroud.

ZOSO · Aug 13, 2017

Ok had my first trip out with the clutch fan. Now running down the highway it's tons better. Never once got hot. Temp rise on long hill climbs was less than 10*. my problem came when wheeling all day. On a long climb temp creeped up to 220. I pulled over and let it sit for 15minutes. On thing i did notice at that time was the clutch was very loose when that hot. there was no resistance.

So my question is whats the best clutch for the metal fan?

ntsqd · Aug 13, 2017

Over years of observing this, consistently the best clutch for a clutch fan is OEM. There is a reason why they're expensive, and they're worth it. That wouldn't stop me from first trying to find one in good condition in a JY first.

chuzie · Sep 3, 2017

pbwcr said:
What I bought is https://www.amazon.com/Motorcraft-YA220-Radiator-Fan/dp/B000CJ2PKM and the 2792 Hayden clutch shown on the link. And Ford F87A-8600-EA = YA220.
Regards, PaulW

Don't bother going to the yard and pulling one of these fans. I went through 20 explorers today and all had axial cracks. Not worth saving $30 if I end up destroying a $500 radiator IMO. Ordering the one on amazon.

Also, according to the jeep thread, the 11 blade is from 98-01 and 12 blade is 95-97. He liked the 11 better because the hub was smaller and provided more blade exposure.

ntsqd · Sep 3, 2017

I'd be inclined to go with the 98-01 fan because it replaced the 95-97 fan and is very likely to be the better design. But not just because it has a smaller hub. More blade near the hub isn't much of a gain by itself. I'm also more inclined to use fans with an odd number of blades. No scientific reason that I can point to, just intuitively prefer them.

nvrstuk · Sep 3, 2017

Odd guys like odd numbers TS!

ntsqd · Sep 3, 2017

Hey! I resemble that remark.

What I'm dimly recalling, and could be completely wrong about and not surprise me at all, is that odd number blades on a fan tend to not have harmonic noises/vibrations and so tend to be a bit quieter. I've noticed that even numbered automotive cooling fans are rarely an even number of blades. They exist, but they're less common than odd numbered blade fans. At least IME.....

sykanr0ng · Sep 3, 2017

If I recall correctly on older cars that did have even numbers of fan blades the blades were not spaced at the same angle.
Which would seem to support the idea of harmonic vibrations being a problem.

ntsqd · Sep 3, 2017

Even odd number bladed fans have inconsistent blade spacing.

73azbronco · Sep 4, 2017

I'll throw this out again, the plastic fan uses a clutch that only locks up to about 70% of the rpm, the metal fan clutch is for heavy duty truck use and locks up to about 90% of the rpm. This was verified through the clutch manufacture tech folks and their parts manual.

ntsqd · Sep 4, 2017

I guess I've been under the false assumption that fan clutches were thermally sensitive rather than RPM sensitive. Seemed logical given the bi-metal spring on the front of most of them.

toddz69 · Sep 4, 2017

ntsqd said:
I guess I've been under the false assumption that fan clutches were thermally sensitive rather than RPM sensitive. Seemed logical given the bi-metal spring on the front of most of them.

Everything I've read indicates they're thermally sensitive.

Todd Z.

Heat torture cooling system test... Exploder mech vrs Tauras electric fans...

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