Blue fan clutch mod...Thread has gone to hell, read at your own risk (1 Viewer)

[landtank]

Well if the difference in cooling is do to the radiator then the idea that the trucks that had the aluminum radiator were more prone to HG fail because of that might well have been accurate.

Thanks for the post back. I'm interested in where you go from here as I might be marginally OK with my setup only because I have the 3 row rad in there. And a little cushion as far as cooling goes would be nice.

 

[Cattledog]

I think the fan is engaging at the right temp but needs more coupling. That is why I will be trying the 5000 wt oil. Well the fact that the oil is dirt cheap helps too. I will be swaping in the old clutch after topping it off with the 3000 wt oil.

 

[Cattledog]

Update on the fan clutch mods. Yesterday, I was running the clutch modded to 95 degrees and topped off to the bottom of the holes on the reservoir. I topped it off with 3000 wt. using OFNA silicon diff-lock oil from hobby town USA. About 9 buck for 50 to 75 ml. I still had some cooling issues with the AC on at full blast, non recirc. And windows open. I even downshifted to see if higher rmps would cool the truck further. No luck.

Today, landtank asked me to top the clutch off Aussie style, top of the reservoir holes. I did so with more of the 3000 wt oil. I had no noticeable lock up issues at idle but more tension than yesterday via holding the fan. With the AC on full blast the raven tai modded needle rose about 2 widths higher than middle of the gauge, better than yesterdays test. So, I down shifted to 2nd at 40 mph –gave about 3000 rpms – that was able to cool the truck to about two needles widths below the middle of the gauge. I am getting closer.

So my interpretation is, the clutch is over filled using the Aussie fill method, reason the clutch is not disengaging enough at higher rpms and over cooling. The clutch is modded correctly/close to the temp I want for engagement. I think the truck has much more cooling potential than any of us are taking advantage of currently.

Next test is less oil and 5000/6000 wt oil. Any thoughts or comments?

 

[cruiserdan]

I put 2 tubes of 10,000 in yesterday afternoon (no timing changes). We'll see what happens.

 

[landtank]

Excellent testing Cattledog. It would seem that my original fill level was about right then.

I agree that we now need to move up the viscosity and the fact that with the over fill of 3000cst you were able to excessively cool the engine, we have to be close to the optimum viscosity for both cooling and MPG.

3 scorching days of heat next week, great for testing.

thanks for the help

 

[landtank]

I put 2 tubes of 10,000 in yesterday afternoon (no timing changes). We'll see what happens.

Dan, was this added to the clutches oil or replacing the clutches oil?

 

[Cattledog]

CruiserDan, do you have the 3 core rad. or the 2 core Al rad? I wonder if the clearance is less with the 3 core. Correct my memory, but you have a 0.75" spacer on the fan clutch too due to the supercharger. Not much distance for the fan to flex. If you would like I can measure my distance from fan tip to rad core. I would consider looking for clearance issues while reving to 4500-5000 rpm in park with the truck fully warm and fan engaged. Having the fan eat the rad would suck. Could that be another reason for the ringed fan in the original supercharger package?

 

[SUMOTOY]

CruiserDan, do you have the 3 core rad. or the 2 core Al rad? I wonder if the clearance is less with the 3 core. Correct my memory, but you have a 0.75" spacer on the fan clutch too due to the supercharger. Not much distance for the fan to flex. If you would like I can measure my distance from fan tip to rad core. I would consider looking for clearance issues while reving to 4500-5000 rpm in park with the truck fully warm and fan engaged. Having the fan eat the rad would suck. Could that be another reason for the ringed fan in the original supercharger package?

CD:
See post #78 (+ >) in this thread, btdt. I definitely had the problem you describe with the 10k cst fluid....

Scott Justusson
'94 FZJ80 Supercharged, er, modded fan blades

 

[cruiserdan]

Dan, was this added to the clutches oil or replacing the clutches oil?

I emptied the old stuff and got about one and one-half tubes worth out. I put two back in and the level was just above the bottom of the holes. I rotated the hub and the holes would shear a bit of the silicone as it rotated.

 

[cruiserdan]

CruiserDan, do you have the 3 core rad. or the 2 core Al rad? I wonder if the clearance is less with the 3 core. Correct my memory, but you have a 0.75" spacer on the fan clutch too due to the supercharger. Not much distance for the fan to flex. If you would like I can measure my distance from fan tip to rad core. I would consider looking for clearance issues while reving to 4500-5000 rpm in park with the truck fully warm and fan engaged. Having the fan eat the rad would suck. Could that be another reason for the ringed fan in the original supercharger package?

I am running a completely different blade, 16361-65020, off of a 94 3.0 V6. It is smaller in diameter than the stocker and the blade tips do not flare out toward the radiator. The individual blades are also significantly stiffer than the stock blades. Several WOT acceleration tests last evening on freeway on-ramps, with the engine shifting at ~4800 RPM (and an audibly roaring fan) resulted in NO blade contact.
Yes, my fan is spaced and I have a 3 row. The blade will hit the lower tank before it hits the core. One run is not conclusive, I need to get the motor hotter by hooking up the boat.

 

[landtank]

It would have been nice if we knew where your plate was adjusted to, just for comparison sake.

Cattledog's plate seemed to be adjusted to 110* and we then advanced it to 95*.

Look forward to your results Dan.

 

[cruiserdan]

The slots were off-center with the larger opening to the left. A counter-clockwise adjustment would widen it even more (if that helps any).

 

[Cattledog]

Great to hear no interferance. Did you ever mod your temp gauge? Good luck with the tests.

 

[cruiserdan]

I have an ISSPRO gauge with the sender in the upper water neck.

 

[Cattledog]

What are the normal temp ranges when running with AC on? Before and after the modded clutch? Any change?

 

[landtank]

Dan, seems to be the same but with what Semlin reported simple position isn't really a good measure to what temp that plate was calibrated to.

 

[cruiserdan]

What are the normal temp ranges when running with AC on? Before and after the modded clutch? Any change?

Too soon to tell accurately. Last evening was cooler than it has been due to some rain, although is was not raining during the run. I did notice the engine running cooler than I would have expected and cooler than the norm. As low as 185 on the freeway, with the A/C blowing hard and the aux fan OFF.

 

[Tools R Us]

Took mine out and beat it in the rocks. Due to some mud and being too bullheaded to ask for a spotter a few times it was a good test, complete with some good rock impacts and more carnage than I have ever gotten in one day on the trail with this truck. It a long day of playing in the rocks, loads of idling and slow going.

Very happy with the performance. Of the four late model 80's in my end of the pack, mine was the only one that didn't have the typical off idle ping when hot and torqued hard, mine has historically been the worst of the bunch. I only have the stock gauge, when pushed hard it would move up to half way, then would ping. Didn't see that on this trip, the needle stayed about two widths under half. We are going to upgrade the fluid in a couple more trucks this week and see what results we get. Comparing several trucks on the same trail, configured close to the same, it was obvious that mine pumped much more air, better suction at the condenser face and much higher volume of cooler wind under the truck.

I hit 4800 rpm shifts a few times, with the impacts and flexing the little foam blocks are still intact. If this trip didn't do it, I don't think that fan clearance is going to be a problem for stock configuration trucks.

 

[landtank]

Glad you had no issues with the fan flex. Sounds like the 10k actually was too much as you were running cold. Cattledog saw this same thing when he over filled his with 3k oil.

Did you by chance notice an oil pressure increase at idle?

 

[Tools R Us]

Glad you had no issues with the fan flex. Sounds like the 10k actually was too much as you were running cold. Cattledog saw this same thing when he over filled his with 3k oil.

I don't think I am running too cool. The thermostat is working at the correct temp on the clutch and the motor temp is regulated by it's thermostat. It's probably thicker than necessary and would bet that the valve never opens more than the first step? We are going to do a couple of more soon and will try them in the 7000-8000 cst range to see how that performs.

The A/C vent temps have been stable, not seeing the idle temp increase that was common before.

Did you by chance notice an oil pressure increase at idle?

Have been watching it and so far looks normal. It's been cool (100F max) and raining here and haven't had a good hot day to test in, so the results may change