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electric fan converion

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electric fan converion

Postby mattmannz » Mon Jun 16, 2014 6:57 pm

After a deep muddy bog on the weekend my recently rebuilt viscous fan sliced open my radiator.

After doing some research I will probably go with a set of AU falcon fans with an all alloy radiator.

Redline have an all alloy tig welded radiator that has a 40mm core versus the stock 29mm. I will tap the top tank and fit a two stage thermo fan switch and tig on some brackets to mount the fans.

Anyone got any thoughts?

Cheers
Matt
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Re: electric fan converion

Postby topgun94 » Tue Jun 17, 2014 7:55 am

I went to electric. Came back to old faithful very quickly. It didnt cool as well and the fan self destructed after its first easy 4wd session
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Re: electric fan converion

Postby stardog » Tue Jun 17, 2014 8:54 am

I made that mistake as well I had twin thermo fans both shat themselves on a big hill on freeway couldn't pull over any where when I noticed my temp gauge went right up in the red cost me a engine the new engine has the original fan on it now and i will be keeping it that way.
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Re: electric fan converion

Postby geeves » Tue Jun 17, 2014 2:49 pm

My wizard is a rebuilt viscous but that is road only. Bighorn though its a toss up between electric and viscous. I didnt slice open the radiator but from the top of the zigzag to home used 6 litres of water after attempting the bog in slippery forest a little quick. High centre between ruts stops you very quick. Able Smith radiators tested it in there tank and at 0.5psi air was coming out in 7 places. Went to a half nissan pulsar fan running continuous and it was ok but not great. I overheated on the zigzag but that was towing a zuke at the same time. Went back to viscous and within 6 months all the blades fell off and more bruises in the radiator.(also the radiator bought online from a well known Auckland wrecker was near solid with mud with a coat of fresh black paint to disguise but thats another story) No leaks this time. Then as I was wrecking Lewises Mu I put the radiator from that radiator and fan into the bighorn. Its a 14 inch aftermarket fan but not 100% happy with the result. It climbs to 100C on hills but never higher but at the same time doesnt eat radiators. I havnt got round to the thermo switch yet and might not considering the type of use that truck gets.
If you are interested I do have a nissan pulsar twin fan here that should fit your truck. Its too wide to go in the ubs55 but looks like it would fit the wizard so should fit your truck providing the thicker radiator doesnt use up all your room. You would have to figure out how to mount it but shouldnt be hard. It shifts a lot of air
Sanding your knuckles before starting work can help. That way you cant skin them
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Re: electric fan converion

Postby mattmannz » Tue Jun 17, 2014 8:30 pm

I have a spare plastic fan which I will keep in the back with the old viscous fan hub.

Most people who switch to thermos and have issues don't use a big enough unit or use poor quality parts.

Set of au fans with shroud going on. These are off a 5L v8 and the dimensions are very close to the Bighorn radiator. I suspect they will cool my truck easily. Will wire them up with an off/on/auto switch and a thermo switch in the top tank.

Will post pics soon.
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Re: electric fan converion

Postby HarryVL » Wed Jun 25, 2014 8:42 pm

I'm running a Supacheap Calibre electric fan on my bush truck.14 " I think.It just fits between the top and bottom tanks.It's on the outside to stop all the mud getting hurled around the engine bay but it's surprising how much crap the belts and pulleys shift.The fan tends to pack mud into the radiator but at least the blades bend outwards in deep mud or water if I forget to switch it off.Also leaves room to bolt the viscous fan back in easily if the electric one dies on a trip.Ifitted a thermo switch in the thermostat housing to control it.It's all been in there about 10 years now and hasn't given any trouble.Harry.
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Re: electric fan converion

Postby MrRevhead » Thu Jun 26, 2014 6:28 am

Hmmmmm this has me thinking..... My new viscous hub has failed after less than 20'000k :evil:
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Re: electric fan converion

Postby mattmannz » Mon Jun 30, 2014 8:00 pm

I am close to finished.

Have cut the AU fans down to remove the stock mounting points. Fans are about 15mm wider than the radiator and about 80mm shorter.

Made up some new mounting brackets to bolt the fan to the stock shroud mounts on the radiator.

Made up a wiring harness with three changeover relays that fits in the stock fuesbox in the engine bay. The fans run at 6v in series at low temp, and 12v in parallel at high temp.

Having a boss welded into the top tank for the BMW thermo switch to screw into.

Coming together.
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Re: electric fan converion

Postby mattmannz » Mon Jun 30, 2014 8:11 pm

Got about 15mm between the fans and the pulleys. Hope its enough.
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Re: electric fan converion

Postby geeves » Tue Jul 01, 2014 3:50 pm

you need to block all the places the fan can pull air past the radiator ie the 2 areas in front where the fans overlap the radiator and whatever the cutout is on the second picture. Those openings can rob you of 50% of the airflow esspecially if the radiator is half full of mud.
Otherwise nice job
Sanding your knuckles before starting work can help. That way you cant skin them
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Re: electric fan converion

Postby mattmannz » Tue Jul 01, 2014 4:56 pm

Once I have everything sorted and finalised I will fill the gaps with some plastic strips. I have had to mod the fan assembly a number of times so the filling will be nearly the last thing I do.

Radiator is in at the engineers getting a plate tigged on and drilled and tapped for the thermo sensor.

Hoped to have it running this weekend.
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Re: electric fan converion

Postby mattmannz » Sat Jul 05, 2014 4:00 pm

Close to being finished.

Top tank tapped and thermo switch fitted. Three changeover relays fitted into stock engine bay relay/fuse housing. Override switch installed inside.

Time to take it apart and paint the brackets.
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Re: electric fan converion

Postby mattmannz » Mon Jul 07, 2014 7:40 pm

Fans in and running well.

Couple of small issues. The thermo cut out on low temp is 82/75 but the truck runs around 78 so once the low speed fan kicks in it doesn't turn off unless you idle.

I have a higher temp switch which I will replace which should sort it.

By turning the fans onto manual high speed mode the truck temp drops very quickly! You can see the gauge drop. Will get the truck down to 72 at idle.

Truck hasn't got hot enough yet to activate the 88c high temp mode automatically. Small trip this weekend to test them out under load and in water.
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Re: electric fan converion

Postby iananita » Tue Jul 08, 2014 10:36 am

Have you got a/c?

I found that the a/c worked better with both fans running at idle than the standard fan.

How noisey are they?
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Re: electric fan converion

Postby mattmannz » Tue Jul 08, 2014 5:00 pm

Ac is long gone.

At slow speed they are about the same noise as the stock fan but on high speed they are a lot noisier. Can't really hear them inside the truck tho.

Motor feels more responsive without the viscous fan as well.
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