Fox T-Bird/Cougar Forums

Technical => Engine Tech => Topic started by: Sick88Tbird on January 12, 2007, 11:13:27 AM

Title: Flex-A-Lite electric fan
Post by: Sick88Tbird on January 12, 2007, 11:13:27 AM
I recently had my fan clutch take a permanent lunch break on me, so I decided it was time for an electric fan.  I know I could piece something together from the junkyard, but a call to jeg's and I had the whole thing at my doorstep the next day.

The flex-a-lite part no. (185) for '79-'93 mustangs fits our cars just as good as it does the 'Stangs.  It's amazing how noticeable it is going from broken stock parts to aftermarket speed parts.  I would highly recommend it if you're looking for a no-hassle alternative.  I should probably call them and tell them to market the  thing for '83-'88 T-birds/Cougars too...lol.

-Don
Title: Flex-A-Lite electric fan
Post by: JeremyB on January 12, 2007, 12:18:37 PM
This is a good idea if you have a stock engine and want a 'set it and forget it' mod with no JY scrounging and a 1-day turnaround. 

But, if you're like me (an buttstuff-retentive engineer), buying a Flex-a-lite 185 isn't the best option. The 185 runs ~$300 with shipping. A "Taurus" fan will run ~$30-60 shipped from a JY, take 2-3 days to arrive and outflow the 185 by just under a 2:1 margin. A "Mark VIII/MN12" fan will run about the same price as the Taurus and outflow the 185 by more than a 2:1 margin. The major downside to the MarkVIII option is that you need to trim the fan shroud if you have a V8.

You can used the money saved to buy a more flexible all-in-one controller (DC Control FK-35 [$120] / Flex-a-lite VSC [$110]).

Add on another $10 for aluminum angle/plate for mounting...and you end up with a far more capable system, for over $100 less.

Just my :2c: 
This wasn't meant to knock your purchase.  Everyone's goals are different, which merit different routes to achieve them.

[SIZE="1"]On edit: Flow figures wrong...see post #7[/SIZE]
Title: Flex-A-Lite electric fan
Post by: Red_LX on January 12, 2007, 12:24:11 PM
I bought two cheapie 12" fans off ebay, got a flexalite adjustable temp fan controller, built my own shroud, and wired it up so the fans can't run when the car is shut off and they come on automatically whenever the fan controller tells them to.

whew!

Works pretty good although I still seem to have a hard time really getting the car to stay cool in stop & go traffic. I may have to upgrade to "good" fans sometime in the future instead of these cheapie ones.
Title: Flex-A-Lite electric fan
Post by: Sick88Tbird on January 16, 2007, 10:56:25 AM
I'm sorry, but I find it difficult to believe that stock Ford fans will flow 3300cfm...considering 2800cfm is sufficient for up to 260hp.  And it came with an adjustable controller that works very well.

So a taurus fan flows just under 6600cfm...sorry but that is laughable, at best.  Maybe you've been misinformed about the flex-a-lite 185.
Title: Flex-A-Lite electric fan
Post by: Red_LX on January 16, 2007, 11:28:16 AM
Found some auction on ebay that claims the Mark VIII fan can flow "up to 4300 cfm." :dunno:
Title: Flex-A-Lite electric fan
Post by: V8Demon on January 16, 2007, 01:02:24 PM
Almost every reference I've seen about the Mark VIII fan states they flow more than 4,000 CFM.  I've seen as high as 4,800. 

Here's a good read:  http://forums.tccoa.com/showthread.php?t=8133
Title: Flex-A-Lite electric fan
Post by: JeremyB on January 16, 2007, 01:43:02 PM
Quote from: Sick88Tbird;124158
So a taurus fan flows just under 6600cfm...sorry but that is laughable, at best.  Maybe you've been misinformed about the flex-a-lite 185.

My original post contained a few brain farts. The Taurus/MarkVIII/MN12 fans don't outflow the 185 by a 2:1 margin. cfm is non-linear wrt current draw.

The DC Control website has an excellent page on calculating theoretical fan flow [Link (http://"http://www.dccontrol.com/intp3.htm")].  If you plug in the correct inputs...you get the following outputs...

Title: Flex-A-Lite electric fan
Post by: Bob on January 16, 2007, 02:14:20 PM
Quote
I recently had my fan clutch take a permanent lunch break on me, so I decided it was time for an electric fan. I know I could piece something together from the junkyard, but a call to jeg's and I had the whole thing at my doorstep the next day.


Yeah but if you have a problem with the aftermarket fan you can't just run in a NAPA or autozone and buy a fan motor off the shelf and be running in an hour.. thats why I like the factory style fans like the mark 8 and taurus. Plus the markviii fan is very quiet I heard alot of aftermarket fans that sound like jets about to take off..
Title: Flex-A-Lite electric fan
Post by: Red_LX on January 16, 2007, 02:58:44 PM
How many amps does one of those Mark VIII fans pull?
Title: Flex-A-Lite electric fan
Post by: Johnny Cougar on January 16, 2007, 03:48:03 PM
I believe the MarkVIII fan draws around 80 amps at startup, 50 amps once its running.  You will most likely have to upgrade to a larger alternator.  If you are running an MN12 5.0, you will need a Mustang 3G 130 amp alternator or better, and get a custom bracket extension to put it into your stock alternator bracket.  Lonnie Doll sells the wiring kit for a Mark fan, wiring kit for a Mustang alternator to MN12, and alternator bracket.  He can be found on http://www.tccoa.com or http://www.blueovalchips.com.

Oh, and if you do get a MarkVIII fan, get the 1998 fan if you can.  It flows better than the other Mark fans.  And don't cut off more shroud than you have to.  The closer the blades are to the radiator, the less the fan will flow.
Title: Flex-A-Lite electric fan
Post by: Red_LX on January 16, 2007, 04:50:01 PM
Quote from: Johnny Cougar;124192
I believe the MarkVIII fan draws around 80 amps at startup, 50 amps once its running. 


Holy Jesus. :eek:
Title: Flex-A-Lite electric fan
Post by: jncocowboyx on January 16, 2007, 04:50:25 PM
i have a ford taurus fan in my 88 cougar with a 5.0 and it cools just fine.
Title: Flex-A-Lite electric fan
Post by: Sick88Tbird on January 16, 2007, 05:04:04 PM
I'm sure a taurus fan does work fine, I'm not knocking it, but I knew it was absurd to think it flowed that much.  I'm sure flex-a-lite knows how much their products really flow...they wouldn't be claiming 3300cfm if it didn't produce near that much flow.  Plus, I'm not pulling a billion freakin' amps...lol.

"The DC Control website has an excellent page on calculating theoretical fan flow. If you plug in the correct inputs...you get the following outputs..."

The key word there is theoretical.
Title: Flex-A-Lite electric fan
Post by: JeremyB on January 16, 2007, 05:22:50 PM
Quote from: Sick88Tbird;124197
The key word there is theoretical.

The only thing missing from DC Control's theory is fan blade efficiency. Do you think flex-a-lite's blades are more efficient than the OEMs? Their motors sure aren't. So, while it is just theory, it is very close to reality and quite valid.

Quote
Plus, I'm not pulling a billion freakin' amps

That is why you use the money you saved by buying a JY fan to buy a variable controller. A MN12 fan can match the 185's maximum output with just over 8A (instead of 18A). A Taurus fan will give you slightly better cfm per amp due to the Taurus' more efficient motor...but it still has more room to crank up the cfm if needed.

Quote from: Red LX
How many amps does one of those Mark VIII fans pull?

Approximately 105A at startup, 42A @14.4V [Source (http://"http://www.corral.net/forums/showpost.php?p=3663236&postcount=6")]

Quote from: Johnny Cougar
Oh, and if you do get a MarkVIII fan, get the 1998 fan if you can. It flows better than the other Mark fans.

Actually, the early MKVIII fans flow better than the later fans. I can't remember the year they changed the blades though. Later MKVIII fans shared blades with the MN12 fans.
Title: Flex-A-Lite electric fan
Post by: Sick88Tbird on January 16, 2007, 10:20:00 PM
"The only thing missing from DC Control's theory is fan blade efficiency. Do you think flex-a-lite's blades are more efficient than the OEMs?"

I see what you're saying, and yes, I do think flex-a-lite's s-curved fan blades are more efficient than OEMs.

I see what you mean about variable controllers, but amp for amp, I don't think the OEM fans match the flex-a-lite fans.

There are pro's and con's to both the piece-meal junkyard approach and the aftermarket approach...which you choose depends on your preference.
Title: Flex-A-Lite electric fan
Post by: sum_weirdo on January 16, 2007, 10:37:22 PM
I like my Taurus fan, I feel confident that my engine is nice and cool.  Really does need a decent fan controller though, I went for a cheap one and it melted the wires ;)
Title: Flex-A-Lite electric fan
Post by: JeremyB on January 16, 2007, 11:21:18 PM
Quote from: Sick88Tbird;124232

I do think flex-a-lite's s-curved fan blades are more efficient than OEMs.

Why.
Title: Flex-A-Lite electric fan
Post by: Johnny Cougar on January 17, 2007, 03:20:08 PM
Quote from: JeremyB;124199
Actually, the early MKVIII fans flow better than the later fans. I can't remember the year they changed the blades though. Later MKVIII fans shared blades with the MN12 fans.


IIRC, the Mark VIII fans are in no way identical to the MN12 e-fans.  The MN12 fan is a two speed fan, while the MarkVIII is a computer controlled, variable speed fan.  The Mark VIII blades will not bolt up to the MN12 fan motor.

Unless you do some fancy stuff, when you hook up a Mark VIII fan with a regular fan controller, the fan is no longer variable speed, and is all on all the time (at least when the switch turns it on).  That fan will suck small children, Crystal, and Weasle up against your grill.

And according to folks at TCCoA, the 98 fan is the best one.
Title: Flex-A-Lite electric fan
Post by: Red_LX on January 17, 2007, 04:35:51 PM
Sounds like you also need a small nuclear reactor to run the thing...
Title: Flex-A-Lite electric fan
Post by: sum_weirdo on January 18, 2007, 01:20:50 AM
Quote from: Red_LX;124314
Sounds like you also need a small nuclear reactor to run the thing...


Well I wouldn't recomend the stock alternator that's for sure...:tg:
Title: Flex-A-Lite electric fan
Post by: jncocowboyx on January 18, 2007, 01:30:04 AM
what's required as far as input from the computer to run the mark fan? mark puter, or will the t-bird/cougar puter work?
Title: Flex-A-Lite electric fan
Post by: Masejoer on January 18, 2007, 03:29:42 AM
Nothing from the computer. You need to make or buy your own controller, variable speed or not.
Title: Flex-A-Lite electric fan
Post by: Johnny Cougar on January 18, 2007, 10:34:41 AM
Quote from: jncocowboyx;124354
what's required as far as input from the computer to run the mark fan? mark puter, or will the t-bird/cougar puter work?


You can run a Mark computer and convert to the Mark's 4.6 DOHC and 4R70W trans (which would be kinda sweet), or run a stand alone fan control, which is what the 5.0 MN12 guys do.
Title: Flex-A-Lite electric fan
Post by: JeremyB on January 18, 2007, 10:59:43 AM
Quote from: Johnny Cougar;124307
IIRC, the Mark VIII fans are in no way identical to the MN12 e-fans.

The internets say otherwise. The internets also agree with you. :hick:

I spent a while searching for Mark VIII fan posts, and ended up with nothing but contradictory information.

A few posts say the older (93-96) fan outflowed the later fans. (1 (http://"http://www.corral.net/forums/showpost.php?p=1229356&postcount=8"))(2 (http://"http://www.corral.net/forums/showpost.php?p=158411&postcount=2"))(3 (http://"http://www.corral.net/forums/showthread.php?t=109961&highlight=mark+VIII+blades"))
Other posts said the later fans outflowed the earlier fans, or that they all flowed the same (1)(2 (http://www.pro-touring.com/forum/showpost.php?p=25661&postcount=19))
Some posts said the MKVIII and MN12 fans were the exact same except for the motor. Others disagreed. (1 (http://"http://www.corral.net/forums/showpost.php?p=2375725&postcount=16"))(2 (http://"http://forums.tccoa.com/showpost.php?p=63691&postcount=13"))(3 (http://"http://forums.tccoa.com/showpost.php?p=901166&postcount=34"))
Heck, I found a post or two saying the 93-96 fans were 2-speed, but the later fans were 1-speed. (1 (http://"http://www.dfwstangs.net/forums/showpost.php?p=2874822&postcount=2"))

I think the '98 fan is 'best' is because it is the cheapest when bought new, not that it is superior to the other fans performance-wise.
Title: Flex-A-Lite electric fan
Post by: V8Demon on January 18, 2007, 12:31:26 PM
From the thread I posted above:
Quote
The truth about '94-95 (maybe up to '97) MN12 E-fan and the '93-'96 M8 fan.. 

Since i have both, right next to each toher... Just looking at them, they do look the same.. but the connections are the same plugs, but the M8 is only ONE speed, where as the MN12 one is TWO speed... The M8 fan out pulls the MN12 on high..

The shroud IS the same..
The fans blades ARE the same..
The motors are different; F3LU-8K621-AA for the M8, F4SH-8K621-AA for the MN12

Oh and the motor and blades are MADE IN CANADA !! 

Also i Believe the M8 Fan is orginally Bi-wired on the postive side.. i've hooked it up that way for testing, and the 12Ga wiring i was using as a test never got hot, nor the connectors... Also it's how it's wired in a M8..
Title: Flex-A-Lite electric fan
Post by: Sick88Tbird on January 18, 2007, 10:46:45 PM
Quote from: JeremyB;124239
Why.



Because from what I've seen, the s-curved blades(typically) flow significantly more with less amperage draw.
Title: Flex-A-Lite electric fan
Post by: JeremyB on January 18, 2007, 11:16:21 PM
Quote from: Sick88Tbird;124509
Because from what I've seen, the s-curved blades(typically) flow significantly more with less amperage draw.

That might be true compared to 'flat' blades, but not the blade design that the MKVIII uses.
Title: Flex-A-Lite electric fan
Post by: Sick88Tbird on January 19, 2007, 07:52:23 PM
Quote from: JeremyB;124510
That might be true compared to 'flat' blades, but not the blade design that the MKVIII uses.


Yes, I'm speaking in comparison to flat or straight blades, I'm not too familiar with the MKVIII design so I can't speak for that.
Title: Flex-A-Lite electric fan
Post by: JeremyB on January 21, 2007, 01:49:54 PM
Quote from: Sick88Tbird;124609
Yes, I'm speaking in comparison to flat or straight blades, I'm not too familiar with the MKVIII design so I can't speak for that.

The MKVIII fan has a blade that varies the pitch angle wrt radius to give equal flow velocity wrt radius.
Title: Flex-A-Lite electric fan
Post by: Sick88Tbird on January 21, 2007, 06:45:30 PM
The old saying remains true, "you learn something new everyday".  Thanks for the enlightenment.  :D