Plastic fan replacements
 

Anyone have experience with plastic fans...6 blade fan, has alum hub and 4 bolts holding fan onto hub. Since hub is aluminum, does the key slot take the abuse of a model a engine?
Thanks /josh

Re: Plastic fan replacements
 

The fan holds up well. I run it on a speedster at higher RPM than a stock Model A and after about 7,000 miles no problems yet,

Re: Plastic fan replacements
 

I have got 6500 miles on mine.

Re: Plastic fan replacements
 

plastic fans cool well and do not go through the hood when they fail. They do fail...I had one explode. It was 20 years old. For the most part, the small pieces did no severe damage, but did puncture the radiator in one small place that was easily repaired, even though it did require removal. But they look anachronistic, and even novices notice they look wrong when you show them the engine. A study by Model A Times demonstrated that the best cooling fan was the 2 blade aluminum. It not only looks most like the originals, but they are less expensive than plastic fans.

Re: Plastic fan replacements
 

Hi Pat, I have plastic fans on both my Model A's. The one in the pickup has been in for over 10 years and no problems, my guess mileage would be over 10,000 on that fan.
My Town Sedan also has one has been on the engine for 7 years. Took the car to Vancover last year, up I-5 crusing at 55-60 all the way.
As has been said they won't got through your hood.
Regards,
herb

Re: Plastic fan replacements
 

Pat,
Ditto what Herb said!
Relative to comment that aluminum fan "looks" more like original...if your going for originality..use an original! If you going for cooling the model A engine best as possible...hard to match/beat the six bladed plastic fan.
BTW..how that crooked/out of line/out of balance aluminum fan thing that TOM W talked about, working out by now??

Re: Plastic fan replacements
 

The two bladed alum. fan, close to the org. moves more air over the eng. then the four bladed metal or the six bladed plastic [build a better mouse trap]:rolleyes:.
Their was an artical several mo's back in the model A news [I think] where they ran some test on all three fans and the two bladed alum. was the most eff. of the three ;).
It's not how many blades, It's how much air is moved.
I guess if some one came out with a 8 or 10 bladed plastic fan someone would have to have it and tell everone how great it is just because they got stuck with one :eek:.
Don't waste your money on junk, Stick with things that are proven over time.
Mr. Ford knew best ;).

Re: Plastic fan replacements
 

We did a fan comparison in the Model A Times in the Spring 2007 issue. We did airflow tests on two four and six blade fans. The plastic fans work very well we have about 15,000 miles on the sedan with one and have been running one on the phaeton for years.

Re: Plastic fan replacements
 

I tend to strongly agree with Louis. At "what" point does the forward motion of the vehicle push more air in through the radiator than what the fan can pull? If the ram effect of the air through the radiator is hindered by the "wall" that the fan blades have created, it reduces the dissipation effect from what we have been told in racing modern engines. Fan science is a complex thing as I have recently learned as my son & I have begun to fool around with a late-model dirt track car (pictured below). It is a fine-line between pulling enough air to adequately cool vs. excessive horsepower draw trying to turn the bigger fan.

One other question. Is the reason for a modern fan to reduce parasitic drag, ...or to cool the engine better? If the engine is overheating, it probably isn't the fault of a two-blade fan. If I were in your shoes and that was the case, I would want to correct the problem instead of "band-aiding" the parent problem. you never know when the parent problem might get worse forcing you to correct it anyway. Good Luck!!

.

Re: Plastic fan replacements
 

John,
Must be something wrong with your 'fan comparison' testing...according to what is written by these guys! Heck, according to what their saying, "less is more( better)" :eek:
Hmm, mabe there's a market for a NO BLADE FAN...working backward from their logic: a 2 blade being better than a four and a four being better than a 6 blade plastic. John, did you ever test a no blade fan in your comparison:D

Re: Plastic fan replacements
 

Actually, I think it is Jim Brierly that told me for years he didn't run a cooling fan on his Tudor. I have also seen where an original two-blade fan would lose one blade while driving out on a tour, and the other blade was broken off and the tour proceeded again sans any fan blades. Also, at the Dearborn MARC meet a few years ago, I drove a Model A speedster on the Mandatory tour without a cooling fan, ...and the only thing that was difficult is as we were sitting in line waiting on them to pass out the ribbons, the engine was starting to overheat. I just pulled over out into the grass and parked it. After viewing the airplanes we drove back to the hotel and I never even added water to the radiator.

Re: Plastic fan replacements
 

Found this on the internet.


Air through the radiator is the important consideration. That is where the heat transfer occurs. Meauring the air flow into the radiator that results from the turning fan is the test to run. That was done and reported in the Spring issue of the Model A Times. Page 7 contains a chart tht shows the results of three fans, the 2 blade, the 4 blade, and the 6 blade.
In front of the radiator the air speed (mph) created by the fan was measured as:
blades--------2----------4------6
500rpm---4.8--------4.5-----3.0mph
1000rpm--9.0--------9.6-----8.5mph
1500rpm--14----------14-----13.5mph
Now, Check this out and tell me which cools your A best wheather in a parade or on the road. If you are overheating it is not because of your 2 blade fan. Have these test results been contridicted as invalad? If so tell me where and by who!

Re: Plastic fan replacements
 

So let me get this straight.:D If I am driving a Model A along at 15 mph, I am pushing more air through the radiator than what the 6 blade fan can pull, --OR for that matter the stock two-blade is pulling more air than the six-blade can?

Matter of fact, if the chart above is correct, then the 2 and 4 blade fans outperform the 6 blade fans. If this is from MAT's chart in their article, it does seem to disagree with what John is saying unless his position is the 6 blade fans work very very well but just not as good as the Ford fans.

Re: Plastic fan replacements
 

Why doesn't someone make a plastic two-blade fan?
Seems like a nice compromise to the discussion.

Dick

Re: Plastic fan replacements
 

At the last tour my stock two blade fan broke off one shroud and hit the water neck of my radiator, also the water pump case broke in several pieces and the head got a big scratch inside, where the water pumps impeller runs arround.
Should I change this head or did this scratch don't have a affect on running the engine. I also want to use the alloy 2 blade fan and hope this one don't brake off at the pulley like my original one. Have got several prices for my 68-B, because it have had all this original stuff installed. That's why I'm a little pissed off by using reproduction parts now.
Did anybody have good appearence with the Snyders high compression head and could I use my old cylinder stud bolts with it?
Thanks for helping me.

Re: Plastic fan replacements
 

I think that Hardtimes logic is the more blades you have on a fan the more air you move even though the two and four bladed fans have proven to be more efficient then the six bladed fans :rolleyes:.
I have a feeling [as we speak] Hardtimes is out in his garage looking for his old two bladed fan ;)....We never stop learning.

Re: Plastic fan replacements
 

Last time this came up I asked the same question.

Re: Plastic fan replacements
 

I apologize but I am not understanding. Please help me out here. We already have someone providing a decent alloy two-blade fan that looks similar to the original fan and functions equally well as the original. So, ...what would be the gain for someone else producing a plastic two-blade fan?

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I think the biggest problem is fans are being sold and talked about in number of blades only. Pitch is important too! I'm sure a 3 or 4 blade fan with as much pitch as the 2 blade would pull a lot more air than the 2 blade.

I'm also sure its not necessary. If a AA truck could deal with the same 2 blade fan as the A.... well I think that says it all really.

Pulling more air than the minimal that is necessary is a BAD thing. You are making more noise and wasting more power for NOTHING. These are not fans with thermal clutches on them that free up when the air is cool. They have the same drag all the time.

Re: Plastic fan replacements
 

My point is that with the amount of damage a fan failure can produce a plastic 2 blade fan could minimize this. That being said has anyone had a failure of the alloy 2 blade fans as the steel ones do?

Re: Plastic fan replacements
 

The marks on the head from the impellor should pose no problem. The Snyder's 5.5 head is very nice and original looking, and a good thing to add more horsepower. I'm going to use my original studs when I install a higher compression head. Most, if not all the catalogs say to use new studs, but with the loose fit of the new studs I'd rather use my Ford original studs.

two blade fan failure
 

Thanks for helping me out with my question on the high compression head from Snyders.
Has anybody a good experience with the 2 blade alloy fan?

Re: Plastic fan replacements
 

Ha, ha! Actually, my 'old two bladed fan' is hung on the wall waiting to give it to anyone in need..need one:cool:
In fact, I have a four blade on my high spinning B, and a six blade plastic on my stock A.
"PROVEN"...by what method/process/by whom? Have you seen any such proof? Are figures, alone, 'someone' writes ..said proof? Seems so. OK, if written words/numbers satisfy youse guys, go to your catalogues and read what is said about the various bladed fans for Model As and which cost more. Isn't cost usually used as a guide line for 'better' and 'quality' also?
Just like you buy more expensive anything...and expect it to be better..no?
Just like everything else in life, everybody has an opinion and is an 'expert' on fan technology/efficacy..yada! Geeze, it's amazing that we (mostly) agree that the old original fans , after 80 years, are an unacceptable risk.
Now , I've just got to go back to GMC and see if they will take that multi bladed fan off of my 8.1 liter engine and install a two blade...cause it's PROVEN that that's best:)

Re: Plastic fan THANK YOU
 

Re: Plastic fan replacements
 

I had an "extreme duty" fan clutch on my 92 C2500HD which was a big mistake. I installed it to help keep my idling temps down when I converted the A\C to R-134A. I was able to get 36F vent temps in stopped traffic on a 95F day no problem HOWEVER, The fan would actually ROAR going 30 MPH down the road if it was hot enough out.

What really stunk was stop lights on major highways. I couldn't get going because of my fan roaring, waiting for the clutch to free up. If you tried to bring the engine above 3K with the clutch not freed up the belt would squeal. That was one hell of a fan and one hell of a clutch :D.

I'm sorry but that 5+ blade fan moved A LOT more air than ANY model A fan. I'm willing to bet it was able to consume more than 40HP all on its own. Again, pitch matters just as much as the numbers of blades.


The 2 blade aluminum fan is great on the "A". IMO its the only fan for the "A"

Re: Plastic fan replacements
 

have over 60,000 miles on mine from MIKES

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Wasn't the four blade fan stock on the Model A in 30 and 31? Please correct me if I am wrong.

Dick

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Not on any passenger car. I cannot speak for AA's but I am pretty sure they were never used factory on anything.

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I still like to use the four blade fans.Not the pot metal hub ones,but the real thing replacements from the 30's,40's,etc.I do keep an eye on them,after all they are old,but zero problems that I didn't catch in plenty of time.If they have rust in the sandwiched parts I won't use them.My ONLY fan failure was an aluminum one that came apart at the root of one blade.I inspected it a few times in the beginning,but that was just to make sure it was not working loose on the shaft.Then I never bothered again.I don't know if it would have given a warning like a steel fan or not.When the aluminum one let go I was in front of a greenhouse where I knew the owners.They lent me a pair of bolt cutters to lop off the other blade.I never even went back home,I just kept on driving and used the truck the rest of the summer.The next winter I put the four blade back on that was on it when my uncle parked the truck in 1954.It is on there today and doing fine.

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I believe I read somewhere that the Ford company itself supplied a 4
blade fan :eek: for replacement and/or retrofit on Model-A's later in the 30's.
True??.........:confused:

Bob-A:D

Re: Plastic fan replacements
 

There's another option, for those who really want to step up their apostasy game. Dennis Cling sells a plastic fan with serpentine belt drive. The goofy spacing of the blades is supposed to be best for eliminating harmonic vibrations.

http://i29.photobucket.com/albums/c2...acement002.jpg

Steve

Re: Plastic fan replacements
 

Steve,

My GM fans always had that kind of spacing. I always wondered why two blades were kind of off on their own!