A nice score today.

[mjseakan]

Not to hijack the thread, but how do know if I have a flex fan?

Mike

 

[Hemikiller]

Not to hijack the thread, but how do know if I have a flex fan?

Mike

The blades of the fan are flexible, and are offset at unequal angles to help combat noise. Most are 5 or 7 blade. 

http://www.mustangtek.com/fan/D0AE-A.html

 

[mjseakan]

The blades of the fan are flexible, and are offset at unequal angles to help combat noise. Most are 5 or 7 blade. 

http://www.mustangtek.com/fan/D0AE-A.html

Hemikiller,

 Thanks for the reply. I've seen this come up several times and I've been wondering about it.

So if I have a 5 blade fan (mine has 6) but the blades are evenly spaced there's a pretty good chance that it's not a flex fan? 

 

[secluff]

Hello Geoff,

I know most of the regulars here have already seen our numerous posts on these flex fans, but this will benefit any new members. Hope you don't mind the slight hijack of you original shroud post!

The 71's used a five-blade flex fan if equipped with AC or extra cooling option. Those fans (DOAE-A and D1AE-CA) were not the problem fans. In 1972 Ford went to a 7 blade flex fan to increase airflow due to increasing underhood temps from cramped engine compartments, AC, emissions controls, etc. The problem was they were fracturing in alarming numbers

There was a massive recall because of the seven-blade fans fracturing in early 1972 and remained active through the early '80s. Since all the fans have engineering numbers on them, the following are the ID #s for the replacing 5 blade fans:  D2SE-AA, D3OE-AA, D4OE-AA, D6OE-AA, D7AE-AA, D8OE-AA, D9AE-EA. There was NOT a problem with the 70-71 OE five-blade DOAE-A and D1AE-CA fans. Unfortunately, there was a problem with the replacement 5 blade fans fracturing. So the safest OE five-blade flex fan to use (If a Concours car) is the D9AE-EA as it was in use on a lot of later models such as the 79-91 Crown Vic. It was also a service replacement for all the ID #'s I've listed above and was the fan listed for the 73 302, 351 AC Mustang in the final issue (Nov 88) 73-79 Master Parts Catalog. The part number for the D9AE-EA fan is D9AZ-8600-A (Motorcraft YA-153).

  For a daily driver or if originality is not a concern, I would go with a clutch fan. They are quieter and take the load off your engine since the clutch disengages the fan when not needed. I used a clutch and fan for the 79-91 Police Interceptor (351W-HO) that used an 18 1/2" fan and worked great for my setup. You could use that application if you go through a parts house. If using online sources, HemiKiller has suggested a Hayden 2710 clutch and a Derale 17118 18" fan. I have also had some friends that have used Taurus electric fans. The Taurus, Mercury Sable, and FWD Lincoln Continentals have been around for a long time so they would be a good source of donor part.
The 7 blade 429 fan Hemikiller mentioned is a 19" fan and was not involved in the recall. My '72 429 Gran Torino had the 19" 7 blade but had a clutch fan set up. The other two I owned were Q codes and very neck-deep in fan trouble!  :classic_smile:

 

[Stanglover]

Flex fans were used extensively on 71-73s. 5 blade was used on all but the 429 cars, which had a 7 blade. The 4 blade you have was the base fan for 250/302/351 non-AC cars. The 5 blade flex unit was the subject of multiple recalls in the 70's. I personally pitch all of them in the parts bin and run a clutch fan, much quieter. 

Hemikiller, you are far more knowledgeable than am I on this, so I'll take your word for it. I was however referring to Mustangs, not full sized or other models. Personally, I have not seen anything other than 4 blade fans on 351C Mustangs. My buddy has one on his I know. I have seem way too many aftermarket fans added and some of those are just plain scary.

As for flex fans, they are for sure potentially killers, I wouldn't even put one in the scrap bin without destroying it first, in case someone found it a decided to use it. 

I am considering adding a good clutch fan next season as I believe you commented before, they are "air thrashers", noisy as hell and not very efficient with hotter summers seeming to be the norm nowadays.

Thanks for the correction.

 

[Stanglover]

Hello Geoff,

I know most of the regulars here have already seen our numerous posts on these flex fans, but this will benefit any new members. Hope you don't mind the slight hijack of you original shroud post!

The 71's used a five-blade flex fan if equipped with AC or extra cooling option. Those fans (DOAZ-A and D1AE-CA) were not the problem fans. In 1972 Ford went to a 7 blade flex fan to increase airflow due to increasing underhood temps from cramped engine compartments, AC, emissions controls, etc. The problem was they were fracturing in alarming numbers

There was a massive recall because of the seven-blade fans fracturing in early 1972 and remained active through the early '80s. Since all the fans have engineering numbers on them, the following are the ID #s for the replacing 5 blade fans:  D2SE-AA, D3OE-AA, D4OE-AA, D6OE-AA, D7AE-AA, D8OE-AA, D9AE-EA. There was NOT a problem with the 70-71 OE five-blade DOAE-A and D1AE-CA fans. Unfortunately, there was a problem with the replacement 5 blade fans fracturing. So the safest OE five-blade flex fan to use (If a Concours car) is the D9AE-EA as it was in use on a lot of later models such as the 79-91 Crown Vic. It was also a service replacement for all the ID #'s I've listed above and was the fan listed for the 73 302, 351 AC Mustang in the final issue (Nov 88) 73-79 Master Parts Catalog. The part number for the D9AE-EA fan is D9AZ-8600-A (Motorcraft YA-153).

  For a daily driver or if originality is not a concern, I would go with a clutch fan. They are quieter and take the load off your engine since the clutch disengages the fan when not needed. I used a clutch and fan for the 79-91 Police Interceptor (351W-HO) that used an 18 1/2" fan and worked great for my setup. You could use that application if you go through a parts house. If using online sources, HemiKiller has suggested a Hayden 2710 clutch and a Derale 17118 18" fan. I have also had some friends that have used Taurus electric fans. The Taurus, Mercury Sable, and FWD Lincoln Continentals have been around for a long time so they would be a good source of donor part.
The 7 blade 429 fan Hemikiller mentioned is a 19" fan and was not involved in the recall. My '72 429 Gran Torino had the 19" 7 blade but had a clutch fan set up. The other two I owned were Q codes and very neck-deep in fan trouble!  :classic_smile:

Steve, your comments as always are most welcome and I certainly don't mind going off script at all on something that COULD potentially injure someone. The more information that gets out there the better.

As I've said before and not arriving on the scene before 73 in Canada, I don't have clue as to what went before. Canadian Fram Fan division probably made the majority of 5 blade fans and flex fans for the "big three". I never worked in that division , but I do have some knowledge of the testing that went on and have seen the damage one of the flex fans can do to 3" of solid oak.  This is not to say Fram made ALL the flex fans Ford used, there may have been other manufacturers I'm not aware of. 

As for a good clutch fan, I see one in my future on my Mustang, Noise and hotter summers that we seem to be getting, just may convince me to add one next season.

 

[mudbilly]

hmm,  is there a link to a clutch fan bolt on replacement ?  I know I've seen posts on here before, but never really paid much attention. I believe that my fan is original flex. It must have a couple hundred K on it. I ran it without a shroud for 15 years cause I thought it looked cooler that way  :classic_tongue: .  

Then I replaced it with a couple Electric fans (tried 2 different Spal models of , but both versions were way loud, and sucked on alternator .  So I went back to original (that I saved) and bought an after market shroud just because I learned that it was not really on there as a safety issue (which I had always believed from back in the day) but that it actually was used to draw the air through the radiator more efficiently.

Anyway, clutch fan recommendations please .

 

[Don C]

Here's a couple

https://7173mustangs.com/forums/topic/34604-71-mustang-351c-adding-clutch-fan/page/2/?tab=comments#comment-370804

https://7173mustangs.com/forums/tutorials/article/33-how-to-upgrade-302-to-a-thermostatic-clutch-fan/

 

[Stanglover]

Here's a couple

https://7173mustangs.com/forums/topic/34604-71-mustang-351c-adding-clutch-fan/page/2/?tab=comments#comment-370804

https://7173mustangs.com/forums/tutorials/article/33-how-to-upgrade-302-to-a-thermostatic-clutch-fan/

Thanks Don, Great info. Now I just have to remember where to find it! 

Is there a way to archive links like that, I ask. (Rocketfoot)

 

[mudbilly]

https://7173mustangs.com/forums/tutorials/article/33-how-to-upgrade-302-to-a-thermostatic-clutch-fan/

What makes the clutch engage and spin the fan blades ?  I notice one of the reviewers on Summit comment that it slips at idle and doesn't cool. At idle is where I definitely need the cooling

 

[Don C]

A thermostatic spring engages the fan when reaching a pre-set temperature.

 

[Stanglover]

What makes the clutch engage and spin the fan blades ?  I notice one of the reviewers on Summit comment that it slips at idle and doesn't cool. At idle is where I definitely need the cooling

 I agree, idle operation when HOT is what I need to. Perhaps the one mentioned was faulty, but something to check into.

 

[mudbilly]

A thermostatic spring engages the fan when reaching a pre-set temperature.

That is what has me confused. what temperature is actually being monitored ?   I would think that the clutch would have to be monitoring coolant temperature in order to come on when needed ?   

 

[Hemikiller]

That is what has me confused. what temperature is actually being monitored ?   I would think that the clutch would have to be monitoring coolant temperature in order to come on when needed ?   

The fan monitors the temperature of the air exiting the radiator. Same same. 

https://www.haydenauto.com/media/5670/fan-clutch_operations-ts_6980012.pdf

 

[mudbilly]

OK, now I get it,  But I also notice that it never does reach the same fan speed as a non clutched version. So the blades would have move more air in order to do the cooling of the original fan,.

 

 

[Stanglover]

Well this post has evolved from the 351C fan shroud I bought, to the fans themselves and on to clutch fans. This is all great info and I'm happy people are getting good information, me included. I too am certainly going this route for next season and I'm adding this tread to my brand new "Note Pad" , thanks to Rocketfoot. 

Looking through, the Hayden thermal clutch 2710 (there is a non-thermal, same number on R/A) seems to be the preferred choice over the Derale versions, but the preferred fan is the Derale 17118  18" 6 blade fan. The shroud has a 19" diam. opening, so hopefully 1/2" per side will be enough to take up any engine torque twisting, really don't think that would be an issue on mine, but could be on more built engines.

I note that the 17118 is currently not available anywhere, but should be after mid November. I thought I'd just mention that incase someone was eager to get it done.

Thanks for all the contributions.

 

[secluff]

Geoff, I appreciate you being a good sport with what originally started with your shroud find. The ID # number on the shroud was what piqued my interest. I'm sure the version Master Parts Catalog (USB, CD, Paper Fiche) most members are using is the Final version of May 1975. That number was not in any of them. I even checked my Lincoln/Mercury books. I finally found it in an old June 1971 fiche. At least we now know there is another shroud that is comparable with the cataloged shroud in the 65-72 MPC.
I know the flex fan discussion appears occasionally, but for the sake of any new members that may not be aware of the issue, it's important to make them aware. I was taking delivery of my first ever special ordered new car at Riverside Ford in Macon Ga in May '72. Before I left, the service manager had come up to the sales dept to warn me about leaning over the front of the engine while it was running. There had been a fatality involving a shop service tech at another Ford dealer! A recall letter was received later.

 

[Stanglover]

Geoff, I appreciate you being a good sport with what originally started with your shroud find. The ID # number on the shroud was what piqued my interest. I'm sure the version Master Parts Catalog (USB, CD, Paper Fiche) most members are using is the Final version of May 1975. That number was not in any of them. I even checked my Lincoln/Mercury books. I finally found it in an old June 1971 fiche. At least we now know there is another shroud that is comparable with the cataloged shroud in the 65-72 MPC.
I know the flex fan discussion appears occasionally, but for the sake of any new members that may not be aware of the issue, it's important to make them aware. I was taking delivery of my first ever special ordered new car at Riverside Ford in Macon Ga in May '72. Before I left, the service manager had come up to the sales dept to warn me about leaning over the front of the engine while it was running. There had been a fatality involving a shop service tech at another Ford dealer! A recall letter was received later.

Thank you Steve. That's very interesting indeed about the shroud. Now MY mind is trying to get around the fact that I have two identical shrouds, both off 71 Mach 1's. Were they BOTH replacements for originals? As I said before, I do know that my rad had been replaced, so was the shroud damaged somehow  and replaced as well, or were D0OE -C shrouds actually used on early 71 Mustangs. Bottom line is it's an original Ford part and it fit and works. 

On the flex fan issue, best advice is NOT to risk any of them regardless of the part number or the time they were made. I wouldn't even want to use the aftermarket ones. They just plain scare me.

 

[Stanglover]

Just to finish off this post, I got the "Caution Fan" decal/sticker thanks to our good friend jpaz, so here's a pic of the final installation. Job done, good enough for the girls I go with.

 

[jpaz]

Looks really nice Geoff!