Man...that fits like it was meant to be.
LJ78 Prado BIG Cooling Fan Upgrade
- Thread starter GTSSportCoupe
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GTSSportCoupe
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- #22
It sure does. Looking back at the pictures, it is pitiful how small a fan Toyota put in these trucks. What were they thinking? Trying to reduce parasitic loss on the already gutless engine perhaps? I wonder how different the Prado story would be had Toyota put a good sized fan on from the factory? So unfortunate.
While this is a great idea, I wonder what will happen over time or when revving the engine. All engines move slightly when the power output is increased and the mounts start to flex more. How much of a gap is there between the fan and the shroud?
The electric fan will require the same amount of HP to run as a clutch fan to pull the same amount of air through because it makes the alternator work harder. Even if there was a difference in the amount HP used, it would be miniscule and you would never recover the cost of the electric fane in fuel savings.
Are you getting any rub? With the engine sitting on rubber mounts and the radiator shroud fixed solid( well sort of) , I would have thought the engine would be leaning the engine over a bit.
GTSSportCoupe
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- #26
Tiny bit of rub at the top is all I've seen so far, and it is not from engine movement, but more from fan flex when it pulls lots of air. Had I made my spacer about 3mm less thick there would be no rub. Really ANY fan would be an upgrade compared to what was in there though. Don't have to use the v6 3.0l fan. A friend just gave me a fan from his 97 Isuzu Trooper that looks like it would fit well. It also is a MUCH better design than the Prado one. Also made by Aisin.
Back to engine movement. These Prado's are very stiff trucks. Even when wheeling, the frame/body do not seem to flex. Engine mounts are very solid and the most movement is just vibration at idle.
Have you done any temperature checks yet?
GTSSportCoupe
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- #28
No I have not. Ambient temp is sitting around 12C where I live now, so truck basically sits at thermostat temp all the time no matter what. Will probably be another month before I do some serious towing (camping trailer) and push the motor. Might catch a 20C day then, and can let you guys know how it goes.
You can do your testing in Southern Georgia where it hit 32-33C several times last week. 
GTSSportCoupe
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- #30
You can do your testing in Southern Georgia where it hit 32-33C several times last week.
Wow, that is warm. We won't see that until July (thankfully!).
Minus the miserable humidity..... 32 in Victoria is heavenly...
engines don't care though
engines don't care though
Those of us who were around Toyota when the 3.0 V6 with it's ringed fan (16361-65010) first came out affectionately referred to it as "the exploding truck fan".
Sometimes the ring would crack and the the blade would come apart violently, taking out the fan shroud, battery, radiator, fan belts and pounding the hood all to hell.
That blade was phased out after the 1991 model year.
Sometimes the ring would crack and the the blade would come apart violently, taking out the fan shroud, battery, radiator, fan belts and pounding the hood all to hell.
That blade was phased out after the 1991 model year.
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GTSSportCoupe
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- #33
Geeez. Maybe I'll put the Isuzu Trooper fan in then. ANYTHING but that puny little piece of crap I first pulled out.
Really though, what percent chance is there of this happening?
I presume it happened enough to prod Toyota to change the design of the fan for the 1992 model year.
In my 36 years in the car business that is the only example I am aware of where such a significant cooling system change was made in the middle of a model run.
Place whatever significance you like on that observation.
In my 36 years in the car business that is the only example I am aware of where such a significant cooling system change was made in the middle of a model run.
Place whatever significance you like on that observation.
GTSSportCoupe
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- #35
Thanks Dan. I researched into this a bit this morning. One thing I noticed, is the exploding fan thing seems to be more common the further south one goes. I wonder if the plastic becomes brittle from the repeated higher temperatures encountered in the south? I have not found any report of this in Canada. The plastic of the fan I installed to my land cruiser seemed quite pliable still. Regardless, I may swap to the other 'big fan' I have from the Isuzu Trooper just to be safe.
I suppose climate could be a factor. It is a bit warmer in New Mexico than your neck of the woods. You might look into the 92-95 3.0 fan 16361-65020. that is a conventional design.
I tried an electric fan out, got the biggest one I could squeak in there. In the end it did not even come close to the clutch fan. But then again my engine does have issues. Pretty sure I have a small crack as I did have a look the other day and saw bubbles in the overflow. I only have a problem if I take it up a long hill or tow (which I do). If I'm just city driving, I don't really have a cooling problem. I work at a aircraft maintenance facility, and may be able to make the part (or have it made), so I would definitely be interested in the drawing if you get around to it.
GTSSportCoupe
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- #38
Sounds like you are going to have to bite the bullet and do that head. If you have the skills to do it yourself, you can save heaps of $$. I be you can do it for between $800-$1500. Do you ever loose coolant?
With regard to the spacer, I'll post some more pictures I took with the dimensions so that you guys can make them if you want.
VI Cruzer, have you replaced the fluid in your viscous clutch? It makes a huge difference to cooling even with the stock fan.
In other news I towed with the new fan last weekend. Probably about 1500lb trailer (two 250cc bikes on steel trailer), and about 1000lb in my truck (including heavy canoe on top). Did 90km/h over the Malahat (6-8% grades), and had no temperature issues in 20C ambient. I found when the viscous clutch engages and the fan really starts working, it does pull in toward the radiator quite a bit. I had some interference issues with the shroud at the top and the ring part of the fan wore a hole through the shroud, but no biggie. Did some wheeling on this trip, and the fan never once hit the sides of the shroud. Frame/body on the 70 LWB seems super strong and don't flex at all.
I'm going to trim the top of the shroud to better clear the ring, and maybe form a new piece out of sheet metal which I'll rivet over top to give more clearance and still protect fingers from the fan blade.
I think I'm going to stick with the ring fan design, primarily because I'd be concerned with other large fans interfering with the radiator when the blades flex at full viscous clutch engagement and high engine speeds.
With regular inspections for cracks you may see it before it explodes.
Hey Nick, thanks for the input. I had done the clutch fan mod, but am trying a brand new one. Seems to work about the same as the old one post-mod. I do lose a little bit of coolant over time I think, but most of the time I can pour back in from the overflow, and that fills it up. I think it depends how hard I push it over the hills.
I wanted to do most of the GTS mods before I change the head, as I only want to do it once. I next want to remove the EGR system, and will work on larger exhaust this summer.
I wanted to do most of the GTS mods before I change the head, as I only want to do it once. I next want to remove the EGR system, and will work on larger exhaust this summer.
