Bobzilla MegaDork
June 16, 2017 8:23 a.m.

Electric fans

So the truck has the ticking time bomb flex fan bolted to the water pump. Running 3k rpm for longish stretches I need to get rid of it. Why would this not work? Downsides? It currently has a 34" core, AT trans radiator on it and sitting in hot traffic never gets over 190. I would think this would cover it, right?

minivan_racer UltraDork
June 16, 2017 8:31 a.m.

I used one of those with the sensor that pushed into the rad fins on my old v6 Dakota and drove 100+ miles a day in all weather including stop and go with no issues

Bobzilla MegaDork
June 16, 2017 8:39 a.m.

I'm seriously considering this. The new harness is prewired to supply power to one, so wiring it up will be easy(ier). Doesn't help I watched the episode of Engine Builders where they tested these and lost close to 30hp on one.

I was planning on leaving the current fan shroud as well. Good idea or bad?

minivan_racer UltraDork
June 16, 2017 8:41 a.m.

I did it mainly to try and gain mpg which I did marginally. I could tell the truck was slightly less gutless though.

Bobzilla MegaDork
June 16, 2017 8:43 a.m.

I've heard (and seen) the damage those flex fans cause when they let go. That's my #1 motivator. power? great. economy? sure, I'll take 15.1 over the 15 I get now. No blowing through the hood? Hell yes.

TiggerWelder
TiggerWelder Reader
June 16, 2017 8:59 a.m.

There is a dyno test of a series of fans on Youtube, the Roadkill guys did it. It took like 18hp to run the fan at redline, like 9hp, which should be about 4.5lbs of gas per hour, or about 3/4 gallon. On my Suburban, that would be about 1mpg improvement, which is nearly 10%!

I am using later model twin electric fans, a factory style harness and running it off the ECU.

81cpcamaro Dork
June 16, 2017 9:01 a.m.

Electric fans are a good idea, just not sure I would trust one that cheap. I have used a Flex-a-lite 160 in a few vehicles, and it worked great. 2005 and up Tahoes and Suburbans (maybe Silverados too) used a twin electric fan setup, and they have 34" wide radiators. Should be easy to get one from a pull-a-part.

rslifkin Dork
June 16, 2017 9:22 a.m.

Get an OEM electric fan setup if you can. Either a big single fan like the Taurus / Mark VIII fan or duals, depending on what will fit the rad better. Make sure it's shrouded well with flappers in the shroud to allow air to escape when on the highway.

Just watch the temps when towing on the highway. If there are any natural airflow issues in that chassis, an e-fan will make them obvious (unlike a clutch fan, it won't push enough air against high pressure to mask poor engine bay ventilation).

alfadriver MegaDork
June 16, 2017 9:23 a.m.

The core reason trucks still have belt driven fans is because those fans can move a lot more air than electric ones can, and for a LOT less money.

If you are never going to push the tow limits of the truck, it's unlikely to be a problem.

But if you do, well, spend the money on a BIG flow fan, or get a new flex fan.

alfadriver MegaDork
June 16, 2017 9:24 a.m.
rslifkin wrote: Get an OEM electric fan setup if you can. Either a big single fan like the Taurus / Mark VIII fan or duals, depending on what will fit the rad better. Make sure it's shrouded well with flappers in the shroud to allow air to escape when on the highway. Just watch the temps when towing on the highway. If there are any natural airflow issues in that chassis, an e-fan will make them obvious (unlike a clutch fan, it won't push enough air against high pressure to mask poor engine bay ventilation).

Again, be aware that car electric fans don't need to flow the same amount of air as truck mechanical ones do. So be careful.

Bobzilla MegaDork
June 16, 2017 9:34 a.m.

This thing is a racetruck. It'll never tow anything, ever. I already have a truck for that.

When the engine gets a rebuild (down the road) I was already planning on an aluminum radiator/dual fan kit. This was never meant as a long term solution.... just for a couple seasons.

68TR250
68TR250 Reader
June 16, 2017 9:42 a.m.

The fan on the '89 S10 Blazer with the 2.8 seized. I took it off and put a puller fan on it with a switch. IT has been on there for for 10 years or so and it has never caused a problem. You do have to remember to turn on the fans when sitting at red lights etc.

jere HalfDork
June 16, 2017 10:27 a.m.

If we are just talking about cheap eBay slim fans then I've had good experiences with them. I ran one to the factory fan wiring. It only came on when stopped ideling in traffic. (There were two fans on the car but the second only came on for the a/c). No fan in the same condition meant overheating. No reliability issues after a few years of use

GameboyRMH MegaDork
June 16, 2017 10:38 a.m.

The way I see it, buying aftermarket electric fans is always a bad idea. They're always more expensive, less reliable, and harder to find replacements for than OEM/junkyard fans.

The only problem you need to look out for when doing an electric radiator fan conversion is the potential reduction in maximum airflow - if you need a really powerful fan, go for the Ford Taurus fan. They draw nearly 40A peak so you will need some exceptionally beefy relays to power one.

Dusterbd13 UltimaDork
June 16, 2017 10:45 a.m.

The lead in your harness is a relay trigger wire. Do not hook it directly to the fans.

Also, go junkyard. Cheaper and better in the short AND long run. I typically reuse them when the radiatior is upgraded instead of the aftermarket ones, and have never had a fan failure.

Vigo UltimaDork
June 16, 2017 10:48 a.m.

No ac on this truck? It's a little extra effort to wire a fan so that your ac turns on your cooling fan but your cooling fan doesnt turn on your ac.

Bobzilla MegaDork
June 16, 2017 11:03 a.m.

NO AC. Also, the power wire is a 4ga power wire to feed the relay for the fan. It's a 30A fuse on the block.

EDIT: I really find it hard to believe that I'm going to get a junkyard radiator, relays and thermostat controller for under $50.

alfadriver MegaDork
June 16, 2017 11:38 a.m.
Bobzilla wrote: This thing is a racetruck. It'll never tow anything, ever. I already have a truck for that. When the engine gets a rebuild (down the road) I was already planning on an aluminum radiator/dual fan kit. This was never meant as a long term solution.... just for a couple seasons.

Unless you REALLY like it, of course.

alfadriver MegaDork
June 16, 2017 11:40 a.m.
GameboyRMH wrote: The way I see it, buying aftermarket electric fans is always a bad idea. They're always more expensive, less reliable, and harder to find replacements for than OEM/junkyard fans. The only problem you need to look out for when doing an electric radiator fan conversion is the potential reduction in maximum airflow - if you need a really powerful fan, go for the Ford Taurus fan. They draw nearly 40A peak so you will need some exceptionally beefy relays to power one.

For the fan/hardware etc- I'd also wager that they are better than aftermarket.

But there will be work to adapt it to work on the truck. There isn't likely to be an OE fan for this truck (regardless of who make it).

The trade off- aftermarket fans will be easy to fit, but less reliable; OE fans will be reliable, but harder to make fit.

Furious_E Dork
June 16, 2017 11:45 a.m.

In reply to Bobzilla:

I agree, the pricing on that eBay kit is really attractive, but the JY fan and relay should at least be close. Think I paid $35 for the Taurus fan and Volvo relay in the RX7.

Edit: I've also got the stock dual fan setup off of my Camaro still. IIRC, I think it survived the accident OK, but I'd have to check that nothing is cracked or anything. It's yours for shipping cost if you want it (junk yard might still be cheaper.)

Cactus Reader
June 16, 2017 12:00 p.m.

I bought a new Taurus fan (Thunderbird application technically) and a junkyard Volvo relay. No more overheat issues on an f350 ramp truck. I did feel the need to upgrade my alternator though. Biggest issue was that the flex fan I removed ate the hoses before I got rid of it.

Bobzilla MegaDork
June 16, 2017 12:01 p.m.

my main issue with going with an OE setup is the hackery I'll need to do to the stock shroud. with this one I can put it on the radiator, leave the shroud and be good to go until I swap it all out.

snailmont5oh HalfDork
June 16, 2017 3:54 p.m.

If you put an aftermarket fan on the radiator (I've been using Mr. Gasket fans on my Fairmont for 8 years now, had to replace it once), don't attach it to the rad with those silly zip ties. Make brackets. One of the zip ties rubbed a hole through one of the tubes in my rad. Lesson learned.

Cactus Reader
June 16, 2017 4:52 p.m.

In reply to snailmont5oh:

Should have stuck with regular zip ties. Those silly ones are just trouble.

EvanB UltimaDork
June 16, 2017 6:40 p.m.

I have not had good luck with cheap slim fans. Junkyard OEM fans are a better idea.

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