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Fan/efan debate thread

Discussion in 'Performance' started by Mooseman, May 7, 2017.

  1. Mooseman

    Mooseman Moderator

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    Since I've been here, there has been this never ending debate over belt driven fans and electric fans (or efans). This video just came out from from Enginemasters which irrevocably proves how much horsepower and torque each type uses (efans were inferred as they used the no fan baseline for efans).



    However, I remember a truck show on the now defunct Speed Network where they did some mods to a Dodge truck where they were checking rear wheel horsepower changes as they were going and switching from a clutch fan to efans only gained just under 1 HP.

    My own personal experiences with efans were mixed. Although I did find I had HP and MPG gains, cooling was marginal and A/C performance was degraded at idle. Once I put back a thermal clutch fan, no issues but MPG did suffer a bit (no hard numbers, sorry). We have to realize that GM engineers went cheap on us by giving our platform a marginal radiator and compensated with a big clutch driven fan instead of efans that all the other truck platforms got.

    I have seen that there is a Dodge car based aluminum radiator that fits to allow efan use. But that, the efans and controller starts making the setup expensive. And. because there is no constant A/C power that doesn't cycle with the clutch, controlling the fans with A/C use is problematic as you don't want the fans cycling on/off with the clutch. Maybe adding a delay circuit on the feed from the A/C clutch might work.

    I can say when I had the efans, all that space was fantastic. Made replacing the radiator and alternator just a trivial thing and just opened up the engine bay. Here's my original thread on my install at the time:
    My efan setup (Montana/Venture efans)

    Now after seeing that video, I MIGHT revisit efans. I have a set from an SV6/Uplander which seem to pull more air compared to the older Montana/Venture fans and may actually fit a little better. I can reuse the controller I had in my old EXT but have to replace the sensor as the wire is quite flimsy and broke right at the sensor.

    So what's your take on efans? Is it worth the trouble and expense? Should be used only on performance builds?
     
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  2. AWD V8

    AWD V8 Well-Known Member

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    I had 4.3 Jimmy that I switched to an e-fan. It was a consistent runner in the 1/4 and when I switched to an e-fan I picked up 1/10th of a second.

    It was much more responsive to the throttle. Before the e-fan when I hit the throttle it would just about break the tires loose. With the e-fan it would spin the tires every time off the line. The engine was responsive at all speeds.

    I never bothered about MPG because I don't really care anyways but I would imagine that it would improve also.

    The engine was also much quieter and the water pump bearings could last longer.
     
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  3. littleblazer

    littleblazer Well-Known Member

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    I've thought about the constant power for the a/c. My thought was to tap into the circuit that runs the little light on the snowflake button on the module. That is my solution. Its cool and all but marginal for us. I also like the sound of the locked fan clutch on my truck once it gets hot out. It just never disengages after that.
     
  4. Mooseman

    Mooseman Moderator

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    That might not work because the light isn't always on when the defrost is on, or it's on when the A/C is not running because it's too cold out.

    i still think some sort of delay circuit fed by the clutch power would work.

    I wish I had a way to measure CFM from these fans just to see if one is better than another. All I can do is go by feel and sound.

    I think I found something that would work. A time delay relay:
    https://www.amazon.ca/Timer-Delay-Relay-Hours-Cycling/dp/B00PD65UGA
     
    Last edited: May 8, 2017
  5. Capote

    Capote Gold Supporter

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    The e-fans idea is something I've always considered being that my rig is a performance oriented build, but after talking about it with others in various places on the forum I am most likely never going to do it. It would seem the gains are minimal and almost unnoticeable (atleast on our platform), as well as it not being a very wallet-friendly mod. Yes it's great to have all the room, i'm ALL about making an engine bay less-crowded (my Cutlass was almost completely rid of all unnecessary b.s.) , but it's just not that vastly beneficial on this platform it would seem.
     
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  6. Blckshdw

    Blckshdw Moderator

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    If/when my fan clutch craps the bed, or my radiator spring a leak, then I'll consider making the switch, depending on how my funds are looking. One of our former members down here has a large metal break, so I was planning to make my own shroud out of a sheet of aluminum for a while.
     
  7. Capote

    Capote Gold Supporter

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    The fact that I already replaced my OEM radiator is another reason i'll more than likely make the switch.
     
    Last edited: May 8, 2017
  8. paul2005tb

    paul2005tb Well-Known Member

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    One minor advantage of an efan is that with a body lift you could also raise your radiator. Raising the radiator protects the bottom 1/2 of the radiator from road debris.

    Also, it seems that if you are in a northern state it is worth it but if you are in a very hot area or towing then it is better to stick with the direct mechanical drive.
     
  9. northcreek

    northcreek Well-Known Member

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    I haven't done my 360 yet but, I've converted a few others to E-fans. My most recent is my MH with a 5.7 SBC engine, I did this one mostly for the noise of the clutch fan and I can't believe how it improved the quality of life in the cab.
    I like using the much loved "1993-1996 LINCOLN MARK VIII 2 SPEED RADIATOR FAN". Because junk yard fans are 20+ years old I used a Dorman repop of the original, they're only about $75. Harrison controls out of Canada(HPC) makes a real nice controller that selects the speed based on engine temp. and your preset.
    The AC pressure switch(not compressor side) brings the fan on also,I would like to fine tune this part so that the fan would not be running at highway speeds. I'm thinking that I can maybe do this through the VSS...Mike.
     
  10. HARDTRAILZ

    HARDTRAILZ Moderator

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    Damn... again.

    It is not the power or energy loss or gain.

    It is the 4.2 uses an unbalanced cooling system and efans will NOT cool a 4.2 with a stock radiator under big loads or offroad or in performance driving.

    Efans are great on other platforms, but you can not take that info with a more typically balanced system and apply it to the 4.2.
     
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  11. Mooseman

    Mooseman Moderator

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    That's what he said.
     
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  12. Capote

    Capote Gold Supporter

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    What're you guys opinions of Efans in conjunction with a large aluminum radiator with much more coolant capacity?
    @Mooseman @HARDTRAILZ
     
  13. Mooseman

    Mooseman Moderator

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    Well of course that would tip the balance in favour of the efan setup to properly cool the engine. A/C would still be an issue at idle in very hot weather. The power gains from it? Meh, especially with the cost. Would be mostly for cool factor (no pun intended).
     
  14. HARDTRAILZ

    HARDTRAILZ Moderator

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    If I needed a new radiator anyway and a fan clutch at the same time and cost was say $100 different I would do the rad and efan, but it would take a perfect alignment of it all to make me really consider it.
     
  15. northcreek

    northcreek Well-Known Member

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    As for power gains between the two, the only advantage that I see is that the E-fan only spins as needed.
    When my e-fan comes on you can hear the RPM drop from the additional alternator load, so there is no fan that works for free, they all rob power, the savings is in the time of fan application...Mike.
     
  16. littleblazer

    littleblazer Well-Known Member

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    You'd need something in the range of 6000 cfm to even consider working with stock. I don't believe that there is a fan on the market that can do that. You would still need ~3000 cfm to keep the air conditioning happy with a large radiator. The difference between a properly working ev and Efan you should never feel a sotp difference... I'm having deja vu I think...
     
  17. northcreek

    northcreek Well-Known Member

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    FOUND THIS:
    Mark VIII Fan
    Universal consensus is a rarity in a scene as opinionated as hot rodding, but not when it comes to budget cooling fans. Whether the online message boards you frequent cater to the Chevy, Ford, Mopar, Pro Touring, Pro Street, or drag racing creed, typing “Mark VIII fan” into the search box will yield similar results. Just about everyone agrees that, dollar for dollar, it can’t be beat in terms or airflow, and will cool just about anything you throw at it. That said, “Mark VIII” fan is a somewhat ambiguous term used to describe a variety of fans Ford installed in many of its cars in the ’90s. These fans come in both single- and dual-speed designs, and with different combinations of fan motor and fan blade arrangements. Nonetheless, whichever one you get, they all move serious air. In independent testing, the different variants of the Mark VIII can move anywhere from 4,000 to 5,000 cfm of air.
     
  18. littleblazer

    littleblazer Well-Known Member

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    From my understanding the Mark VIII fan is huge and it's stock shroud are similar in size to what we already have, so the benefit of cleaning up room is a wash... then while its running you lose the same power as the ev clutch at ~2000 rpms... if the alternator can support it. That is the one I'd use though.
     
  19. HARDTRAILZ

    HARDTRAILZ Moderator

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    stock LS1 dual fans will move 10,000 cfm in free air, but not through rad and condensor and such.

    Your Mark numbers look to be the same as the taurus numbers I always heard about with cfm and efans. Both being ford I bet they may be the same.
     
  20. Capote

    Capote Gold Supporter

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    Trying to get an idea if I should upgrade to a larger radiator, with or without an efan setup for the Turbo. I know it'll give the engine a workout and I need to properly vent a Turbo engine as well. I'll have to get measurements off the one I was interested in, too see if it'll fit with the stock fan. Compare it with the stock one we got and such.
     
  21. northcreek

    northcreek Well-Known Member

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    As I said earlier, I used the Mark VIII fan on my motorhome without issue. I can't think of a better test than putting a V8 in a doghouse,under the floor,pushing a 8,000 pound sail,with A/C on while screaming at 3,000 RPM ....and the bitch stays cool.
    Having said that, as with all fans the devil is in the shrouding, the better the fit,the better the cooling.
     
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  22. Capote

    Capote Gold Supporter

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    Just read an article on HotRod about it, seems legit man.:cool:
     
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  23. littleblazer

    littleblazer Well-Known Member

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    I'd bet the radiator in that was a little better then our stock junk. I mean the radiator in my sisters cruze is almost as big as ours is. Actually it may almost exactly be the same size just a little thinner. If we had an extra row of cooling in the radiator I'd say it would work. If you really want I could model it on my computer and calculate thermal heat transfers to find what we'd need for what cfm not in free air to work. The small opening in our front bumper is also an issue. The portion getting fresh air is only about that large so there's an efficiency drop there too. I can make my truck run low 230s on a 95 degree day easily with a locked thermal clutch. When I'm working the pedal is buried. That's it. I'm also running about 1100 lbs extra all the time at that point too so that's a consideration. The mark fan may be okay at best. That's why I'd start with it. I have no intentions of that though because if I throw the boat behind the truck that math goes out the window. Then I'm also an 8000lb sail. :tongue: if you're going performace oriented then it's a no brainer for efans. For me it wouldn't make sense and I quite enjoy the 33 degrees at the vent I get in the summer. :thumbsup: people grab jackets when they ride with me in the summer lol. I also spent a lot of time dialing my a.c. system in to get there. And we're off topic now...:smiley_kill:
     
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  24. northcreek

    northcreek Well-Known Member

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    From what I'm seeing the 360 platform uses the same size radiator regardless of engine. You would think that what's good for the 6.0 would be good for the 4.2.
    What makes the Atlas engine such a heat machine :confused:
     
  25. Mooseman

    Mooseman Moderator

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    It's not that. On both engines, they skimped on the radiator. Single row, low capacity. Only difference is the outlet locations as they are different. That's why they over compensated with a huge clutch fan. In the old days, you could upgrade the radiator to one for a vehicle with A/C with more rows. Not.on this platform.
     
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