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Technical Auxilliary fans

Discussion in 'Traditional Customs' started by SHARKO, Aug 21, 2019.

  1. SHARKO
    Joined: Mar 7, 2010
    Posts: 84

    SHARKO
    Member

    My J-2 Olds has been a good road car for a long time running 175-190 in hot weather on the hiway. It is a little high strung with a 270 cam and big valves and never has liked to sit in traffic at 95 degrees. (190-210)Now I've finally added AC. The stock fan is reputed to be a good puller and is mounted close t.o the radiator. Olds didn't use a shroud but there are air dams above, below, and on the sides of the radiator. I want to try a pair of 10 inch pusher fans to be used in traffic and turned off at speed.
    Which fans block the least air when off, straight blades or S blades? Do some freewheel? Do I have to use zip ties? Which brand do you like? I have tried very hard to keep the engine bay as it could have been in the 60s and want to keep the plastic at least outside of this area. Thanks Pat
     
  2. Jalopy Joker
    Joined: Sep 3, 2006
    Posts: 31,177

    Jalopy Joker
    Member

    there are universal full fan shrouds from multiple sources - might consider going with fan with more blades - anything placed in front of a already partially blocked radiator will not help the problem
     
  3. Why not install a bigger fan with more blades, summit has steel bladed fans in several different sizes, these things move much more air than the original ones and they have kept my cars cool, with no shrouds or additional fans needed. HRP

    [​IMG]
     
  4. G-son
    Joined: Dec 19, 2012
    Posts: 1,276

    G-son
    Member
    from Sweden

    Then that would be my first thought to add.
     

  5. Ziggster
    Joined: Aug 27, 2018
    Posts: 1,697

    Ziggster
    Member

    Engines at idle in traffic do not produce a lot of heat. The issue is getting sufficient cool air through the radiator and getting the hot air out of the engine compartment as quickly and efficiently as possible. A shroud around the fan should have a dramatic effect on the amount of air it can move if done correctly. With AC installed, the air inlet temperature to the radiator will likely increase 5F - 10F as a result of the heat rejected from the AC condenser (assuming it is installed upstream of the radiator). This increase will be reflected proportionally in an increase of the coolant temperature all else being equal. Having said all that, the next step after installing a shroud, would be a thermostatically controlled clutch on the main fan if it was up to me. That would help in keeping things looking stock IMHO.
     
    Just Gary likes this.
  6. I added a 16" Spal fan that is controlled by a thermostat. The fan is a pusher, around 2000 or so CFM. It works quite well. I looked at some on Summit, but wound up getting one on eBay for a lot less. Get a complete kit with the mounting straps, wiring kit. It comes with almost everything aside from solderless terminals, shrink sleeve, etc.

    The base fan I got is 30102048, I would get it with the installation kit.
     
    Last edited: Aug 21, 2019
  7. SHARKO
    Joined: Mar 7, 2010
    Posts: 84

    SHARKO
    Member

    Thank you all. The shroud is a good idea but there is only 1inch between the stock fan and the top hose. Danchuk chevy car or truck pieces might give me a start or I can mavbe get a Buick shroud from Easy Jacks. The Buick fan is 3 or 4 inches back while mine is maybe 1 and 1/2. So I would probably need to fabricate a 2 or 3 piece shroud to allow water pump maintenance. I am concerned that a clutch fan would add too much weight to my pump bearing? The multi-blade fan is a good idea but I don't need to move more air above 40 mph. My hood latch center support means I can't mount 1 big pusher so I was thinking of 2 or even 1 off center 10 inch ones My buddy has 2 12 inch pushers and the stock fan and they work but I think he runs them all the time in hot summer.
     

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  8. Frank Carey
    Joined: Oct 15, 2009
    Posts: 574

    Frank Carey
    Member

    My A/C guy advised me to wire my pusher so it comes on when the A/C does. He said I might not need it for engine cooling but the A/C system would need it. I used the compressor wire to close a relay. Easy. And a thermostat turns it on if engine gets hot. No problems in 25+ years.
     
    AHotRod likes this.
  9. Looks like a spacer on the back side of the fan. Could it come off and not cause the fan blades to hit anything?
     
  10. Hdonlybob
    Joined: Feb 1, 2005
    Posts: 4,115

    Hdonlybob
    Member

    I messed with over (5) different fan set ups to cool my sbc...
    Finally went to (from advise here) a Lincoln Mark VIII 18-inch fan.
    This thing moves some serious air. I am very satisfied, and in 95 degree heat in a long traffic jamb it idles at 185 degrees.....
    Only downfall is it is large...
    Here is some info on it, as well as others.
    Good luck
    https://www.hotrod.com/articles/ccrp-1111-electric-radiator-fans/
     
  11. LEE CHRISTENSEN
    Joined: Nov 24, 2018
    Posts: 29

    LEE CHRISTENSEN

    I to had exactly the same problem as you. I come to the conclusion that a mechanical fan was not the answer without a shroud. I only have 2 3/4" clearance from radiator to fan pulley, so a shroud is out. I purchased a Flex A Lite 238 wave lo boy 16" fan, supposed to flow 3000 cfm. Installed and let car idle to 195 and then turned on fan temp came down to 182.
    Don't know if that would be your answer or not, but so far working for me.
     
  12. SHARKO
    Joined: Mar 7, 2010
    Posts: 84

    SHARKO
    Member

    Lots of good advice. I was hoping to do car shows including Old Marais and a long road trip soon but my bride's business has slowed down the road trip. I will study and seek shrouds but I think my fan is just too close to the radiator and the top hose. Please advise which clutch fan to try. I am concerned by the weight on my pump bearing but these pumps are available. Two AC guys both told me to get the little pusher fans for the condenser which is Vintage Air's largest. I'll turn of the AC for the car show!
    ps.my town car never overheats
     
  13. BJR
    Joined: Mar 11, 2005
    Posts: 9,814

    BJR
    Member

    I would ad a fan shroud before putting electric fans on.
     
    gearhead1600, Cosmo49 and Moriarity like this.
  14. jimmy six
    Joined: Mar 21, 2006
    Posts: 14,795

    jimmy six
    ALLIANCE MEMBER

    Had the same problem. Part of it is the gasoline today. Fan shroud is still the best thing . Mines plastic and has a notch for the upper hose and not a complete lower half. I also put on the 6 blade fan and a smaller water pump pully to speed up the pump idling. Good luck.
     
  15. Elcohaulic
    Joined: Dec 27, 2017
    Posts: 2,212

    Elcohaulic

    Run a 160 thermostat. I would get a clutch fan and adjust the bi-metal strip so the fan comes on at a lower temperature..
     
  16. SHARKO
    Joined: Mar 7, 2010
    Posts: 84

    SHARKO
    Member

    EUREKA! Ozzie on the Classic Olds Forum replied that Olds did in fact have a shroud in 57 part #570694 used on AC cars with a 6 blade fan #569686. He says a factory setup like this cools his 55 AC car. And another fella CW said he had one on a non AC 88. So they may have been optional or a dealer fix. It was going to take me all winter to make a shroud and it would look like a furnace. So if anyone knows where I can get these please advise.










    eureka!
     
    G-son likes this.
  17. SHARKO
    Joined: Mar 7, 2010
    Posts: 84

    SHARKO
    Member

    I searched high and low for the factory ac fan and shroud. Finally I tried a Hayden 2947 low profile clutch and a 6 blade 76 Olds fan. We just drove the Olds from KC to San Antonio and back. It actually ran cold on 60 degree days at 150 degrees in overdrive at 75. As the day heated up the temp rose to 180 or 190 at 80 degrees ambient. But in town it was not so good . I couldn't get no ethanol gas everywhere and the temp rose to over 200 in Austin traffic and I barely kept it running. I never even ran the ac. Hayden says the clutch engages at air temp of 175 and disengages at 135.
    1. How can I lower this spread?
    2. I may just buy the Summit no clutch 6 blade recommended above
    3. I wired for an electric fan and may give up my 60s look.
    Your advice is still appreciated.
     
  18. 6sally6
    Joined: Feb 16, 2014
    Posts: 2,459

    6sally6
    Member

    X-2
    6sally6
     
  19. SPEC
    Joined: Feb 1, 2021
    Posts: 811

    SPEC
    Member

    With a pusher fan you only get around 50% of the cfm of the fan. The air hits the core and bounces off of it.
     
  20. footbrake
    Joined: Sep 3, 2009
    Posts: 148

    footbrake
    Member

    A simple shroud would fix your problem.
     
    Just Gary likes this.
  21. Why not make your own shroud to fit your application?
    I made a shroud from some 1/2" thick MDF, an old T-shirt, and fiberglass resin.
    My fan is a steel 6-blade '55 Chevy fan with about an inch between it and the top hose and less than an inch between it and the bottom hose.
    20201003_054850~2.jpg 20201004_191511_2.jpg 20201006_100526_2.jpg 20201012_102629_2.jpg 20201028_165241_2.jpg 20201028_165454_2.jpg 20201029_085027_2.jpg

    Hope this helps.:)
     
    Last edited: May 17, 2021
    footbrake likes this.
  22. 1934coupe
    Joined: Feb 22, 2007
    Posts: 5,051

    1934coupe
    Member

    I second what HRP says, it is also the easiest thing to do first. And it can't hurt (like chicken soup) try it and go from there.

    Pat
     
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  23. SHARKO
    Joined: Mar 7, 2010
    Posts: 84

    SHARKO
    Member

    Thank you all. That is a beautiful shroud you made. I think I'll take off the clutch and try a 6 blade fan first. And if I can't find part # 570694 I can attempt a shroud.
     
    Just Gary likes this.
  24. 1971BB427
    Joined: Mar 6, 2010
    Posts: 8,717

    1971BB427
    Member
    from Oregon

    I personally don't believe all the myth about pusher fans blocking air to the radiator. Even when they're not being called on they still spin freely as air is being pushed through the blades at almost any speed. And if the motor in the center stopped enough air flow to matter, it wouldn't matter if it was restricting it before it tried to ender the radiator or after.
    I have two cars with pusher fans and both with adjustable thermostats I set to call the fans on at 180 degrees. Neither runs hot, and even on the hottest days, idling in traffic, they never get over 200 degrees. At freeway speeds or any temps under 180 they don't even run; they just coat along.
     
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  25. 55blacktie
    Joined: Aug 21, 2020
    Posts: 793

    55blacktie

    Anything you put in front of the radiator-fan, transmission cooler/ac condenser, will restrict air flow. However, how much air flow do you think you have when idling? Running hot when stationary/moving slowly is quite common for old cars. A pusher fan may restrict air flow at highway speeds, but that's not when you experience overheating. With the pusher fan, you will have air flow when you most need it. Use an on/off switch or adjustable thermostat when you don't. Lots of people are doing exactly what you suggested in your original post.
     

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