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nissan
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Discussion Starter · #1 ·
Basically has anyone replaced the Viscous fan with twin/single electric fans?
Have had a look at Davies Craig website and they recomend 2 X 14inch as a replacement on GQ TD42.
So what are your thoughts?
 

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spend a few extra bucks and get spals, if you buy them off ebay with the dollar near parity you may even save compared to buying the davies craigs off a radiator shop over here. spals flow more air and are a better product
 

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I think there is at least one other thread on this - I have replaced mine with twin fans out of an EL falcon, still waiting on my car (stuck in townsville by closed roads) and then will post a few pics. Cos me under $200 all up including switch, wire and a thermal switch from supercheap. I have mine wired as thermo, off and on with thermo hooked up through the ignition.
Very simple mod and temps sit almost on the thermostat opening temp. Defs worth thinking about if u have heat issues.
 

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Discussion Starter · #4 ·
Cheers, yeah was thinking Commodore or similar with thermo control pretty simple circuit to wire, dollars aren't the issue with this just quality of cooling and my viscous hub is [email protected]#$ED

Mavtroll pics would be appreciated, worse bit is I scrapped a EL and a dunnydore 6mths ago as cook was whinging, didn't bother getting too many parts of them, BUGGER!
 

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Part of the furniture around here
nissan
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Electric fans are fine on road cars, often the fans don't even come on except in city traffic, but try driving off-road/beach in summer with nothing but electric fans. I did this once and was bloody glad I had the mechanical fan still in the back of the Patrol, else it would have been 'all over, red rover'. No electric fan (designed for a car) can push the volume of air that a viscous fan is able to draw.

Cheers

Ray
 

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I did it in ZD30, and, although in Poland there is quite moderate climate, I had issues with them.

Part of their origins were cheap aftermarket fans and too weak electric circuit.

But inherent weakness of electric fans is that they either need much current, if they work frequently, or they switch on only when the engine is really hot. If you stop the engine before they cool it, they will work drilling battery resources, and in fact not cooling the engine but only the fluid inside radiator.

Off road, heavy traffic, or mountain drive make electric fans work hard. I ended with burned circuit, stopped fans and overheated engine. I learned that they need dual battery and properly designed circuit. And maybe an electric water pump to allow fans to cool stopped engine too. I still consider electric fans but only as addition to mechanic one.

There are also some pros:
- you can install additional switch to turn fans off before entering deep water, thus protecting your radiator from being eaten,
- some people claim they can save some Kws - I haven't enough experience to confirm or disagree, but it seems to concern the time when they don't work ;).

Cheers
bulva
 

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KICKEN BACK IN THE BUSH
nissan gq
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I cant see how an engines HP has anything to do with what a fan can or cant push/suck/blow

So IF i had , lets say a heating issue with a patrol,i go whack a lecy fan of a 400 HP monster and itll be all better
Rubbish
Most new cars go electric due to space restrictions
(seen how much room there isnt in an AU Falcon )
The old myth that fans draw heaps of engine HP is really only related to fixed fans
The factory clutch fan on the patrol will and does flow more CFM of air then an electric fan will
Most who have heating issues are not related to the fan, some other issue
Most who convert to electric fans , eventually restort back to the factory set up
So the question remains
IF you have a heating issue with a fan that draws heaps of CFM of air
Does restoring to a set up that flows less CFM of air ,fix the problem
Nope

Theres a gazzillion threads on this issue
 

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Electric fans are fine on road cars, often the fans don't even come on except in city traffic, but try driving off-road/beach in summer with nothing but electric fans. I did this once and was bloody glad I had the mechanical fan still in the back of the Patrol, else it would have been 'all over, red rover'. No electric fan (designed for a car) can push the volume of air that a viscous fan is able to draw.

Cheers

Ray
My twin thermos pull heaps more air than the old viscous fan did, still waiting on my car (stuck on a truck in the townsville floods), fans run for around 30secs to a minute at a time in town, come on pretty much full time offroading, never a heat issue, and I live in Darwin, so not getting much warmer.

People speculating, please don't, if you have never run the system then u just don't know
 

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Part of the furniture around here
nissan
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My twin thermos pull heaps more air than the old viscous fan did, still waiting on my car (stuck on a truck in the townsville floods), fans run for around 30secs to a minute at a time in town, come on pretty much full time offroading, never a heat issue, and I live in Darwin, so not getting much warmer.

People speculating, please don't, if you have never run the system then u just don't know
I had twin Davies Graig fans and they simply couldn't push anywhere near as much air through the radiator, compared to how much the viscous fan could pull air through when things got really hot in low speed driving. Initially, it felt as if the electric fans would work just as good (onroad they were fine), but in the middle of summer, low range driving in the High Country, they couldn't cope. I'd hate for someone to install electric fans and then kill their engine when out in the boonies. If one wants to try this, keep the original fan in the car, just in case.

Cheers

Ray
 

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Yes I do keep orig fan in the car as a backup, but because mine are bolted behind and therefore suck heaps of air through I have had no need
 

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If you go to Nissan you can order the Super Safari dual fan kit. It plugs straight into the socket under the cross memeber of the bonnet (red socket). If your is auto you have to move the oil cooler a little but it all comes good. You can also use the stock nissan fan but you need to do a few mods and if I recall you have to turn it 160 deg to get the holes line up. All the brakets are there as standard you just need to move it around and line it up. I alos think the sockets are diffrent but this can be done by just a simple cut, crimp and join.
 
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Discussion Starter · #13 ·
I keep reading of people saying the Viscous fan pulls more air than an electric but I have not seen any numbers to support this. Does anyone have the CFM raqting of the OEM fan and/ or the CFM of electric fans from various vehicles such as a Dunny door Or foul can.
It would be interesting to compare the facts instead of just going on heresay.



I think that was likley the problem in itself. Fans are much more efficent when sucking through the rad than blowing through it.
If this wasn't the case, the OEM manufacturers would probably find it a lot easier to put them in front of the rad instead of behind the bumper where a lof of cars have considerable space instead of behind the rad where space tends to be much more scarce.

Spot on Glort you need to know the OEM fan CFM, on the Davies Craig spec sheets they show fan curves, air flow verses air pressure, this is why I would think some have good and others bad set ups, cooler air fows more volume
 

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The nutty professor
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My twin thermos pull heaps more air than the old viscous fan did, still waiting on my car (stuck on a truck in the townsville floods), fans run for around 30secs to a minute at a time in town, come on pretty much full time offroading, never a heat issue, and I live in Darwin, so not getting much warmer.

People speculating, please don't, if you have never run the system then u just don't know

i guarentee your clutch fan was faulty then, i found the specs ages ago , the factory clutch fan draws around 6000cfm at full lock up @2500rpm, falcon thermos draw 3300 cfm @ 12 volt , there is no comparison between the 2
 

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The Bear
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That would be 3,300 cfm each surely, so total would be the same or better, also there are better rated fans than the falcon fans available, further the electric fans dirtectly pull through more surface area than the standard vis fan and shroud because about 1/4 to 1/3 of the gu 4.2 radiator is not under the fan shroud,( left side) so a significant part of the radiator is not being cooled, then again - and I stand to be corrected - , the bottom hose is the water pump inlet ( gleaned from other posts) so the left side of the radiator may not have any more heat to give up so why bother pulling air through it. Is that how it works.?
 

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The nutty professor
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3300cfm total , even a 14 inch high performance spal fan pulls about 1800cfm max , no pressure/ vacume

just read that before about the radiator not having the shrowd allow the air to be pulled through the entire radiator , seems like a good mod to do , the more radiator coverage the better
 

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The Bear
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thanks, thats pretty poor air flow really. Well off to clark rubber try and get some foam to seal the radiator when I put it back in later. Going to try welding the cracks in the blade too, but have ordered a new one anyway.
 

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Jaycar sell a liquid level sensor kit for $20 that senses water and through a relay will turn the fans off through a water crossing.
 

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Don't know, I put a 14" thermo on my troll, and took the viscous fan off.
A. I picked up some power, and Notice no difference between 33's and 35's so power has to have come up.
And B. my temp sit at half on the guage with the new thermostat and I very rarley turn the thermo on unless i'm stopped or creepying alone slowly.
I would like to run falcon thermos as it looks neat and fits in well.
 

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The Bear
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Well been down the wreckers measuring up fans, both falcon and holden fan shrouds are about 200mm short, about the same as standard GU 4.2 fan shroud, depth spot on 450mm,. But both would need some fancy bracketing to locate properly. Dozens of fans there, but nothing better.
 
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