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Plastic vs metal vs electric fan..your choice.?

Discussion in 'The Hokey Ass Message Board' started by lowongas, Jul 19, 2011.

  1. lowongas
    Joined: Mar 8, 2009
    Posts: 282

    lowongas
    Member

    Ok..and yes I tried a search but really didnt find an answer...mostly difference of opinions...which I am sure this post will add more to that...Ok..I am in the engine/radiator mock up stage and need to know what to use,fan wise.The is a 1930 Model A Coupe with a (YIKES,who would had thunk it..a SBC in between the frame rails.) Frame was made by someone who used to be on here but isnt anymore,so its not a stock frame we are talking about.I am using a short water pump and 1 groove pulley set-up.I saw a few half metal/plastic flex fans at a swap meet but remember reading here that they are dangerous.I also searched on the net and found ones made of just plastic.I have a few electric ones laying around but I cant seem to decide which to use...and no its not a trad.build.Some input maybe..?
     
  2. RustyNCA
    Joined: Feb 18, 2009
    Posts: 410

    RustyNCA
    Member

    My opinion for what it is worth.

    A. Don't run a flex fan, there is a reason they are cheap and not wanted.

    B. Run a good metal fan and themo clutch setup with a shroud if you have room.

    C. Run the electric fan if you have to, but only if you can't run the good old clutch fan. Run the fan behind the rad as a puller, but make sure that is what it was designed for. If it doesn't cover the rad well, build a shroud for it also, but run as much fan as you can.

    I would be running the fixed clutch fan if I had room....

    Cheers
    RustyNCA
     
  3. Labold
    Joined: Nov 1, 2007
    Posts: 1,219

    Labold
    Member

    If it's not a traditional build, I'd use a good electric fan. They work fine, reduce drag on the motor and help clean up the front of the engine compartment.
    Just say no to the flex fan though...
     
    olscrounger likes this.
  4. scrap metal 48
    Joined: Sep 6, 2009
    Posts: 6,079

    scrap metal 48
    Member

    I run older 4 blade fans on sbc's in my model A builds and never a problem, cools fine and looks traditional because it is......
     

  5. squirrel
    Joined: Sep 23, 2004
    Posts: 55,942

    squirrel
    Member

    yeah, it should have the old 4 blade steel fan as used on most chevys from 55-mid 60s.
     
    Just Gary likes this.
  6. bob giles
    Joined: Dec 4, 2007
    Posts: 147

    bob giles
    Member

    If getting the manual fan high enough, use one of these. It raises the fan 5 inches with a stovebolt short water pump.
     

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  7. An engine (belt) driven water pump and a metal fan blade with a good shroud, properly engineered. Electric fans look like "street rods" and sound like electric cars, are prone to fail and a pain in the ass. A SBC isn't hard to cool. Oh yea, it's got to be a Walker radiator. Just my opnion.
     
    Just Gary likes this.
  8. Gator
    Joined: Dec 29, 2005
    Posts: 4,016

    Gator
    Member

    I've got 4-5 flex fans and a couple of electric fans I've taken off various projects over the years - they're hanging on the wall. I use steel fans and ALWAYS use a shroud. Summit / Speedway / Jegs carry Flex-a-Lite and other brands steel fans, and you can get them from 14" to 19" and either rotation starting at $25 bucks or so.

    Amazes me the guys building 'traditional' rods then lazily slap an electric fan on it - especially those not running a hood.
     
    Elcohaulic likes this.
  9. Von Rigg Fink
    Joined: Jun 11, 2007
    Posts: 13,418

    Von Rigg Fink
    Member
    from Garage

    I like to use OEM mechanical chevy fans..hey whats the chance they will fit and work?;)

    diameter can always be delt with.

    there are some real nice steel fans out there in swap meets and bone yards for next to nothing
     
  10. Amen.
     
    Blue One likes this.
  11. johnny bondo
    Joined: Aug 20, 2005
    Posts: 1,547

    johnny bondo
    Member
    from illinois

    i got a buddy whos running the old divers bell on his flathead. he needed the fan to be lower since his car is channeled and lowered the radiator to match. so he put on an 8BA gen mount and 3 blade fan with a 1/2 inch spacer. so the only thing he has to do now is add another pully to the front of the generator pully to run the fan underneath. kindof a pain in the ass, but with a super traditional car with everything else being old, the electric fan would suck ass!
     
  12. chevyfordman
    Joined: Oct 4, 2008
    Posts: 1,354

    chevyfordman
    Member

    I bought one of Speedway's stainless, chrome center, high rpm flex fans, I run a shroud, it has 12K miles on it and works perfect and is very easy to clean. I love the looks of it too. good luck
     
  13. CutawayAl
    Joined: Aug 3, 2009
    Posts: 2,144

    CutawayAl
    Member
    from MI

    An electric fan is fine for many applications(including most new cars), but a good mechanically driven fan can move more air than even two electric fans. So, the electric vs mechanically driven, it's a matter of what you want and need.

    As was mentioned, a fan shroud improves the effectiveness of any fan.

    If you use a mechanically driven fan with a fan clutch; fan clutches are usually thermostatic, and freewheel when temps are below a pre-set point. Clutches with different temp settings are available. For high reving engines, or engines with oversized fans, there are fan clutches that freewheel above a pre-set RPM.
     
  14. tommy
    Joined: Mar 3, 2001
    Posts: 14,757

    tommy
    Member Emeritus

    [​IMG]
    The only electric fan that I can live with. We had 2 of these when i was a kid.:D Anything else is a cop out. IMHO

    To me the fan is just as important to the over all look of an engine as your valve covers or air cleaners. I don't care for any plastic hot rod parts. I like the old 4 bladed standby but I have used 5 and 6 blade steel fans in the past when there was room. Even the shrouds were steel up into the middle 60s from the factories.
     
  15. musicrodder
    Joined: Aug 24, 2006
    Posts: 65

    musicrodder
    Member
    from Upstate NY

    Mechanical fan behind a Walker radiator, been using for a few years, works great, no problems.
     
  16. Cantstop
    Joined: Jul 11, 2005
    Posts: 239

    Cantstop
    Member

    i read a article in one of the big mags 4 or 5 years ago where they flow tested fans on a dummy radiator with and without a shroud. the testing showed the best performing fan was the stock gm clutch fan with a shroud. none of the flex fans could come close
     
  17. HellRaiser
    Joined: Jun 14, 2006
    Posts: 1,241

    HellRaiser
    Member
    from Podunk, NE

    The four blade steel with a clutch would be great...But consider going with the 5 blade truck fan from a big ole farm truck. The trucks are not for speed, and they do a lot of idling. The pitch on a truck fan is usually greater than is what you will find on the cars. Many times the truck fan blade might be the same pitch using 5 blades. But the fan will be smaller doing the same job. Early flathead Fords were a good example of this.

    When it comes to using a shroud, do run one if at all possible. Again, something to consider. When you do put on a shroud, don't run the shroud without leaving some air in either on the top of the shroud or the bottom. Also, don't have the fan 100% into the shroud. Leave at least one inch of the fan behind the shroud. By trying to make a tunnel effect out of your shroud, thinking it will suck more air. It won't.

    HellRaiser
     
  18. brad chevy
    Joined: Nov 22, 2009
    Posts: 2,627

    brad chevy
    Member

    It all depends on the room you have and the radiator you are running as to what kind of fan to run.The flex fan shouldn"t even be considered.
     
  19. 49ratfink
    Joined: Feb 8, 2004
    Posts: 18,829

    49ratfink
    Member
    from California

    I switched from a regular steel fan to a stainless flex fan on my last car. that stainless flex fan was like a tornado under the hood. when I get my next car going it will have the same thing only with a shroud.
     
  20. _ogre
    Joined: Dec 21, 2009
    Posts: 127

    _ogre
    Member
    from Motown

    bob: never saw that offset pump before, do you have a side view of that? where did you get that?
     
  21. theHIGHLANDER
    Joined: Jun 3, 2005
    Posts: 10,245

    theHIGHLANDER
    ALLIANCE MEMBER

    I'm in the clutch fan crowd too. Hard to beat and even "restored" to an OEM finish they just look right. If you shop around a few bone yards you'll find that the stem portion comes in different lengths. I won't raise my right hand to it but I think any GM will fit the SBC pump pattern.
     
  22. pasadenahotrod
    Joined: Feb 13, 2007
    Posts: 11,775

    pasadenahotrod
    Member
    from Texas

    The stainless bladed flex-fan I put in my 40 Std. Coupe with flexed a bit too much once time after hitting a good bump and ate the face of may radiator slicing about 10 tubes near the upper tank flange and cutting like a knife near the bottom.
    Switched to a stock steel 55-57 X-blade fan after repairing the radiator and never looked back.
    Used the same X-blade type fan in my SBC-powered T roadster behind a recored radtor using a stock T upper tank withour problem too.
    I do like the idea of using a fan clutch if you can get it in there, I couldn't.
     
  23. One of my trucks had a 3-blade fan stock; I switched to a 5-blade because it was laying around; with a shroud, it didn't make any real difference.

    When it comes to fans, that bolt pattern is the same from the 30s to the 80s, you can put almost anything on there as long as it doesn't hit anything.
     
  24. perk30
    Joined: Jun 22, 2009
    Posts: 321

    perk30
    Member

  25. asst. fan spacers are at any parts store new or by choice at any yard 3/8-4 inches long
    look around any old disassembled pile o engines

    fan clutches are thermostatic or speed

    bent or damaged fans can ruin a new water pump pretty quick


    remember fan direction is important too

    best 5-6 blade with thermo clutch +shroud
    next best 4 blade with shroud

    older str. six cyl w ac have a smaller dia multiple blade
     
  26. RustyNCA
    Joined: Feb 18, 2009
    Posts: 410

    RustyNCA
    Member

    And when it comes apart it's like a tornado going through the hood.... In my case it was through the radiator itself..... It was not fun dealing with a destroyed radiator and no fan blade out in the Nevada Blackrock Desert on that 4x4 trip :mad:

    I will never run another flex fan, that scared the *&$% out of me when it came apart.

    Just Saying....

    Cheers
    RustyNCA
     
  27. man-a-fre
    Joined: Apr 13, 2005
    Posts: 1,311

    man-a-fre
    Member

    You want to keep it cool,get a flexalite nylon flex fan,jegs,summit,and speedways has them.Speedways part is 359-415 for 15" 359-417for 17".I run one on my model a with a 434 smallblock chevy and walker z rad and cools fine.They really pull the air!And are rated for 8000rpm. They do rob alot of horsepower due to there extreme pitch of the blades,and they dont flex out much at all .Plus the fans are light and easy on the waterpump .
     
  28. bobscogin
    Joined: Feb 8, 2007
    Posts: 1,771

    bobscogin
    Member

    Nice choice. I'm running one and like it.

    Bob
     
  29. Model A Vette
    Joined: Mar 8, 2002
    Posts: 1,075

    Model A Vette
    Member

    I ran a stainless flex fan when I first built my '30 roadster. It worked OK but it would cut your hand when doing any work on the car. (Not running!)
    I finally taped the edges every time I worked on anything near the fan.

    I ran a cheap aftermarket electric fan for a few years until the blade started to slip on the motor shaft.
    I changed over to a stock FWD fan and shroud from an '88 Celebrity. It has worked fine for years.
     
  30. Deuce Roadster
    Joined: Sep 8, 2002
    Posts: 9,519

    Deuce Roadster
    Member Emeritus

    [​IMG]

    [​IMG]

    The raised pump is the same length as a standard SBC short water pump. (5 and 7/8ths )

    [​IMG]

    If you have room for a standard short SBC water pump ... the raised up unit will fit ... but the fan will be 5 and 1/2 inches higher :D :D

    Do a search here on the HAMB for ZIP water pump. Lots of info and threads.
     

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