electric cooling fan help...

Discussion in 'Engine Performance + Maintenance' started by 135 Honolulu, Jul 3, 2019.

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  1. 135 Honolulu

    135 Honolulu Newbie

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    I have a 1994 GMC Sierra with a 5.7L engine. I am looking to replace the stock fan with an electric fan setup. Could anyone please recommend what size are possible? And, if single or double setup? Thank you in advance!
     
  2. L31MaxExpress

    L31MaxExpress I'm Awesome

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    Personally I would not do it. Just get a fan blade from a Vortec with the tow package and a new clutch. Cooling when you need it and slips along drawing minimal power when you dont. Those metal 5 blade fans suck and in warmer weather the clutch tends to stay engaged sapping power. The 11 blade plastic fan will move 2x the air. My Vortec stays at 178-182°F with a durmax blade and TBSS clutch. With the Tahoe dual fans it would get to 240°F pulling my travel trailer and those fans were screaming. Put the Durmax fan on it and the temp gauge would not budge. Only time I ever saw it get over 200°F was backing the trailer up a steep driveway and tugging it around to park it in a tight spot in 105°F weather with the a/c blasting. I am sure ALOT of that was the 25% underdrive and the 2,800 rpm stall speed. Trans and A/C were dumping heat into the cooling system of a practically stationary vehicle while the engine was being heavily loaded.
     
    Last edited: Jul 4, 2019
  3. kennythewelder

    kennythewelder B31-3 (6-G) certified

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  4. El Tigre

    El Tigre OBS Enthusiast

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    I use/recommend the dual fan setup for these trucks from Flex-a-Lite...
     
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  5. eyeroc87

    eyeroc87 Newbie

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    looking at the 11 blade ACDelco composite for the 5.7 vortec, would it fit the clutch fan on my 5.7 TBI, bolt pattern looks the same, or should/can I put vortec pump on my TBI engine.
     
  6. kennythewelder

    kennythewelder B31-3 (6-G) certified

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    I did that power robbing swap before I did my electric fan swap. I went to the junk yard, and pulled one from a Suburban. I lost power and MPG. The electric fan swap is a much better swap. As I said in this thread before, just click my link. Here is a pic of the bigger fan I installed before I did the electric fans. Also not to mention the power, and MPG gain of electric fans, it is also a big help on your AC system. Electric fans just move more air at idle than clutch fans do. And yes I have a dual electric fan set up now. 20180506_185108.jpg 20180525_141226.jpg 20180530_201242.jpg
     
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  7. AK49BWL

    AK49BWL OBS Enthusiast

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    Electric fans > Engine-driven every day of the week. I pulled mine from a 2001 Ford van, a Windstar iirc. Best thing I've done to that engine to date since my 0411 swap.
     
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  8. L31MaxExpress

    L31MaxExpress I'm Awesome

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    Mechanical fan > Electric any day of the week. I noticed ZERO difference in power under normal driving and no difference in fuel mileage. Fan clutch engaged vs disengaged is about 10 hp though on the dyno. However my fan rarelt ever fully couples unless maximum cooling is needed on a very hot day and I would gladly trade the power for cooling. Electrics draw a good 40 amps and that energy has to come from the alternator. Alternators and electric motors both have conversion loss in efficiency. Its more efficient to have a properly working fan clutch letting the fan practically idle on the end of it. Its direct energy conversion vs multiple stages. Not to mention my engine ran hotter with electrics than the mechanical fan. When the fan clutch actually engages fully the mechanical pulls 2-3x the air volume of an electric fan. Also my A/C is colder with the mechanical fan even at idle with the 25% underdrive than it ever was with the electric fans. At idle on a 105°F day it gets down to 38-40°F with both front and rear units on high fan speed..At idle on a hot day the Duramax fan I run will pull a piece of paper into the grille from 2 feet away, far more CFM than the Tahoe dual fans ever thought about pulling. With the Tahoe dual fans I also put one of the GMT400 pusher fans on it. Made a difference. With the Duramax fan it made NO difference and I ended up pulling the noisy POS back off.

     
    Last edited: Jul 11, 2019
  9. Schurkey

    Schurkey I'm Awesome

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    Thank you. You saved me a bunch of typing.

    It takes a REAL electric fan (or two) to equal a decent fan/cluch assembly. And the electrical power to run it has to come from somewhere.

    The ONLY real advantages of electric fans is that they're really handy with transverse engines, and they do a good job of cooling after the engine is shut off.
     
  10. bugdewde

    bugdewde OBS Enthusiast

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    Isn't the Trailblazer SS fan clutch electronic?
    If so, how do you make this work?
    Interested in this upgrade.
     
    Last edited: Jul 11, 2019

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