best thermo fan to install on the gq?

[peric77]

hi guys and gals. looking to install thermos on my gq but not sure which model thermos from the ford i should be looking for. Which one is the most easiest to install and best.

[BigRAWesty]

Firstly do you use the car for mud or water crossings?
If so stick with belt driven fan.

Water and electrical, no good.

I don't mind the idea of a thermofan aiding the main, but not replacing it..

If your sticking to black top then any fan will require some modifications.

[peric77]

my fan hub has seized and to tell you the truth its running much much cooler but it is much much louder and i can also feel im losing power at take off. I do not want to replace it as when it was working i don't think it was doing the best job of cooling when towing my camper trailer. was getting pretty hot.
So i want to install the thermos for a couple reasons. better cooling, towing, water crossings and cheaper than replacing the damn hub

I know some mods will have to be done but which one is easier, the EL's or BA's or is there another?

[OldMav]

You could consider 2 14 inch Spal fans they shift more air then either of the 2 systems you suggested. But there is a bit more to all this radiator thing and cooling. Your system should be in good condition no rotten copper fins, radiator should be clean inside and out. All the sealing bits around the radiator and mud guard rubber in good order on and on. The pump and back housing needs to be near perfect condition no pits or corroded bits. Thermostat should be checked for correct operation and the depth distance checked to the bypass hole and no corroded bits or pits. You are towing so your cooling system needs to be in as new condition. Maybe consider a brand name larger Aluminium radiator they are easily 20% more effective so you take a bit of load of the fans mechanical or electric even though many on this forum seem to think they are not as good, more water larger fin ratio = more cooling regardless. Don't believe you Nissan gauge 15deg C is half the range of second half of the gauge, check your temp with a VDO or simular gauge just to make sure..

[BigRAWesty]

Well if your doing water crossings I'd steer clear.
Fail rate is to high..

I'd spend the money and repair/replace the hub, they can be rebuilt.
And if your radiator is struggling tonight be time for a clean out.

Like I said I'd fit a thremofan as an aid at most. Half width will help flow a lotzz

[threedogs]

How long has it been since your cooling system had a birthday,??
BTW don't mix coolants, it'll turn to gel
I was lead to believe the twin thermo fans off the EL were the go
you could always mount a switch for water crossings, to turn fans off.

[Ryangtd42]

ive heard au falcon thermos work a treat

[OldMav]

To the OP I assume your GQ has never had a radiator change or clean out and your viscous hub is a little tied. Your proposed plan is fine but as pre-posted you may need to look at the whole system and make a judgement form there. If you need a new radiator then there is a few option for you but money is always going to be the sticking point. So maybe I tell you what I use and why. My original copper core rad only lasted a few months after brand new I hit a water crossing way to fast and a blade broke off which mangled 4 or 5 tubes. Due to my rig not being anything like std output some 180rwkws the rads was doing its job but only just so I had a aluminium core cut for me to suit my GQ as in the early 90's there was only a std rad and genuine at that was the only option. So I make my own radiator the core was a full flat tube 55mm through supplied bt PWR US, compared to the std 40mm 3 tubes, I fitted new alloy tanks which are some twice the volume. Results were the damn thing wouldn't get above 76 degC even with the 85 deg c thermostat. But I had fitted/welded a 5mm alloy ring on top of the bypass hole to generate more fluid flow through the engine. I fitted 2 x14 inch Spal fans off brackets vertically straight onto the core face no shroud. Results were my fans rarely turn on and never turn on at speed and my temps stay a very constant 85deg C, so the thermostat is doing the job it is suppose to do. Due to the vastly more efficient larger core air supply isn't as important. Oh did I tell you how nice it feels not having a mechanical fan making a racket every time you rev the engine mmmm the silence is wonderful, I will never go back to that terrible noise. Water crossings mmm well usually you get out and have a look first so by the time this happens the fans have more often than not turned off after the normal idle heat soak period.

As a general rule the std core is just fine and large enough for most patrols if in near new condition. You can stabilise your temps by fitting a 37mm long base to bypass disk thermostat leaving 3mm of space for by pass criteria or use a STD thermostat with a 5mm thick 6mm wide ring welded to the top of the bypass hole. This mod makes your temps very stable and react to heat loads a lot quicker especially when loaded or towing and allows the thermostat to function as it was suppose to, the Nissan engineers got this bit a little wrong for our higher ambient temps in Australia. Now the other theory to dispel about cooling systems on a TD there is no such thing as too much water/fluid flow if the thermostat is working as intended then it controls flow very VERY well especially if this mod is done. Now to little flow, this is a issue and this can happen on older TD's mainly due to coolant not being updated or we have a few stray electrolysis issues happening causing corrosion in the pump housing. Anyway the back face of the water pump housing has to be ideal so no pits of metal loss, our Nissan engineers didn't quite get this bit perfect they opted for maximum clearance for blade to housing clearance this is fine for colder countries, so even a small loss of metal here slows down flow reducing this clearance to about 3 mm increases our pump flow near double but loads up our fan belt loads. So about 5mm clearance is a good compromise to having more than enough flow in our cooling system. If you have a few mechanical clues you will know how to adjust this pump clearance as it is the same process used on most open impellor ajax or denison water pumps and you will understand the whys. Of note too little clearance will raise the pressure in the system which can be a good thing but not advisable but you can use a higher set pressure rad cap to compensate as I did.

So what I am saying is some of the GQ TD touted overheating issues can be attributed to this very issue due to age if all other avenues have been address. And yes I did this to my TD at 11 klm's new hence my never ever seeing overheat issues even with 180rwkw's. I did all this testing in 1988/89 when I mildly turboed my dad's brand new Nissan leaf ute as it had unstable and terrible temp issues due to his over loading and towing a 28foot van loaded with crap.. Just for interest this old ute got sold out of the family just before Christmas with 2 and a half times around the clock on the odometer discounting the few years of the odometer doing its usual stuck issue. IP pump and injectors were rebuilt twice, once at brand new to fit a compensator and some power goodness and again by me lol but paid for by BP for not tell us they took sulphur out of our diesel, and 2 stroke oil was used ever since. internals never opened. LOL the wonder of a silver top eh that is serviced right with CEM oil flush at every service. Sold with this compression test psi 1# 405, 2# 400, 3# 395, 4# 390, 5# 410, 6# 395, through the glow plugs and an a average crank speed of 190rpm. I think 427 psi at 200rpm is for a new engine. Oh forgot it had water only injection fitted from new.

[peric77]

its a new rad, new fan, rebuilt head, rebuilt turbo, water to air cooler, blocked egr, oil catch. only think it needs is a exhaust and a tune. Im pretty sure it is running lean as i replaced the intake manifold with a nice clean one now. thanks for the info fellas but i think i will add some thermos for aiding and just fork out for a new clutch on the damn fan. then exhaust and tune and hopefully she will run better than new. thank guys

[BigRAWesty]

its a new rad, new fan, rebuilt head, rebuilt turbo, water to air cooler, blocked egr, oil catch. only think it needs is a exhaust and a tune. Im pretty sure it is running lean as i replaced the intake manifold with a nice clean one now. thanks for the info fellas but i think i will add some thermos for aiding and just fork out for a new clutch on the damn fan. then exhaust and tune and hopefully she will run better than new. thank guys

Try the tune first. An engine not in the sweet spot will heat up more..