Tools R Us is a BAD DUDE!

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

cruiserdan

cruiserdan

SupportingVendor Emeritus
Moderator
10 Year 15 Year 20 Year
Joined
Mar 27, 2003
Threads
158
Messages
26,979
Location
Corrales. Hiding from Utah winter
He and I had a long discussion the other day about fan clutches and blades. This man is one of the sharpest knives in the drawer as far as I am concerned ;) .

He indicated to me that the "blue" clutch was one of the best he has monkeyed with and he also outlined his "theory" about how "ringed fans" work. He is a very sharp fellow and I listened to what he had to say and "filed" it in the back of my mind, thinking that he may, or may not, have a valid observation.

Fast forward to my last Powell trip. I had some warm running issues and I condemned my "newish" blue clutch (I have a "ringed" fan because I have a blower).

This evening I deliberately left the engine idling with the A/C on and the aux fan off. The engine temp slowly raised to 210 and I couldn't really hear any air movement. I tried to stop the blade using the "gloved hand" test and damned if I couldn't do it :idea: So, I say to myself "Remember what Kevin said about ringed fans creating a vortex if they are not run in a form-fitting shroud?".

I throttled the engine up to about 2,000 rpm and the fan was pulling. I felt the air movement and there was a significant ammout comming out around the edge of the fan. I carefully placed my hand behind the center of the fan and felt NOTHING, bordering on negitive pressure :idea: .

I am CERTAIN that blown engines equipped with the ringed fan ARE NOT set up properly.

I am now actively studying to find a conventional blade that will fit the clutch and have proper spacing to avoid hitting both the radiator and blower drive on the back-side.


Thank you Kevin for planting that seed in my brain............ :beer:


D-
 
Very interesting!!! keep us posted, I am glad that there are smarter people on here than myself.
 
cruiserdan said:
I am CERTAIN that blown engines equipped with the ringed fan ARE NOT set up properly. D-
Click to expand...

This is very interesting. I noticed on a couple occasions with my supercharged 80 that there seemed to be no air behind that fan. Though I never had any overheating issues like that. Kaderabek, what say you?
 
From what it sounds like, after I read your post 5 times to get the full understanding, It MIGHT be easer to make a shroud that is formed to the curve of the ring fan. Instead of finding a new fan. Just another way to think around or outside the box... Maybe?
 
I do not want to do that and I'll tell you why:

I call the ringed fan "the exploding truck fan" because they have a nasty habit of sucking in the lower shroud extention in the 3.0 V6 trucks they were originally fitted to. when this happens the fan "grenades" and takes out the shroud, battery, air cleaner resonator, radiator and generally beats the s*** out of the underside of the hood.

I'll pass, thanks.......:rolleyes:
 
I'd suggest doing the same test with a stock engine & fan for comparison.

Also, keep in mind that the dynamics with a stationary vehicle are different than when on the road.

Also also, did you check you radiator core for any new build up of grey sludge?
 
I have done that in the past Rich and my radiator is new OEM.

Before blower, when I towed, I could really hear the fan come in on grades and it sounded like it was trying to suck the grille thru the radiator. Not so with this fan.
 
Well I guess that you get to see some great trends at the dealership. Are you thinking a modified stock fan? that might cause some balance abnormalities. Or are you going to hit up the microfish and look at an OEM toyota. If you have the rough needed dimentions you might be able to do a search on summitt racing or jegs for a fan blade. I really don't think that a set of electric fans would be able too cool the beast.. What are your thoughts. If you have the #'s for size I could search, I am only at work. :}
 
The original blade is out of the question because high speed "tip flex" causes it to drag on the backside of the radiator. The fan is spaced out in order to clear the blower drive. any blade will have to end up in a plane that will prevent interference on both sides. I have over 15 different blade part numbers in stock at any given time and I also stock multiple different clutches. I have measured clearances on both sides and I have a general idea about where I need to end up.

I will stack an original blade on top of an original clutch (on top of the bench) and that will be my "target height". I will then subtract the spacer thickness and stack "shorter" blades on the clutch til I hit that measurement. Hopefully the blower drive clearance on the backside will fall in.
 
(sorry for the tangent, but I asked tools R us about fixed fans earlier today and this thread seemed like a good place to continue with that thought)


in (approximately) seven out of every eight threads on fan clutches someone will mention playing around with bolting their clutch...... seems like everytime it is mentioned the installer comes to his senses and ultimately puts the blue clutch in and tosses their bolted one,

but Im curious - would there be a measurable performance or mpg decrease going to a fixed fan? I mean how can our 80's get any slower or any less fuel economy?

besides, if by going to a fixed fan you prevent mucho $$$$ damage to the engine of your $9,000 truck, can't you then justify spending a couple hundred extra a year on fuel?

especially for the guys in the south - SC, GA, FL, TX, AZ, NM

why not a fixed fan?
 
A "bolted" clutch risks over-speeding the blade which leads to broken bits of whatever is in the way when it explodes.
 
I hope you are mentally prepared Dan, for when you get the right combination of parts together. And then when or if you tell us what the right PN is the onslot of orders will be comming your way. Good luck and please keep us informed as always... thanks in advance
 
Dan,

I just was sitting back with my feet on the desk trying to figure out a way to create the ideal world wherein you'd have the massive output of the engine driven fan, but be able to fully engage the clutch with the flip of a switch like an electric fan. Electric activation of a clutch? No way to wire it on a rotating object, tough to make/find. Some powered remote switched clutch? Unimaginably difficult to build.

Then, epiphany! Ok, a tad on the odd side at first, but hear me out. Oh, before I forget, you'll also help maximize effectiveness the closer the fan is to the rad on your spacing, but I think you know this.

So, ya got a heat activated clutch in there already, right? You'd like to turn on the fan at the bottom of Vail pass on a 100 degree day with a trailer - right? Why not use HEAT to activate it? As in a cheap 12V electric radiant heat coil next to the fan coupling with an equally cheap bracket and a dash switch to turn it on and off.

Likely, enough heat could be generated with just a couple hot wires placed almost touching the viscous coupling, and it wouldn't take much experimentation to figure out either how close they need to be, or how hot they need to be to cause 100% lockup within a minute or so. Using an old blower switch with several positions might work to have several levels until you hit the one that gives enough heat to cause lockup without frying things if you left it on indefinitely.

I tried to think of a way to use existing underhood heat, such as piping air from the manifold directly to the coupling, but that's complex. I don't know if you could get enough heat from a coil of hot coolant in front of the coupling you could cause to flow or stop but again this is complex compared to a simple electric heat coil which is essentially a hot wire.

My two centavos.

DougM
 
Electrically activated fan clutches exist. Same concept as an ac clutch. I recall them being marketed to navistar (ford powerstroke) owners.
 
Interesting idea Douglas but the main issue, in this case at least, is the fact that the ringed blade is just not correct in this application. The key to the proper function of the ringed blade setup is a very specific blade/shroud interface. I bet that if I took the blade off and tossed it in the bushes it would not make much of a difference. So, any conventional blade that would fit the clutch and not hit any important bits whilst spinning would be better than what is on there now.
 
First off this observation is the brain child of several people, most notably LandCruiserPhil. :D

We lined up three trucks, Rob's '97 with a weak after-market clutch, Phil's '96 with supercharger and Hayden clutch and mine with a good blue hub clutch, in every scenario Phil's put out the least air by a noticeable amount. Phil has been working on cooling issues as long as he has owned the truck, it's in very good shape and has been very well maintained. It has all of the high tech cooling devices including a Ron Davis Racing radiator, but if it's pushed hard in hot weather it still runs hot, what's the point of having a supercharger if you cant use the power about half the year? We think most of this problem would go away with a better fan.
 
'K,

Phil is also a BAD DUDE then......:D He and I wheeled at CM togther this year and we never really talked about cooling too much.

I WILL find a blade to function in this application, trust me ;)

D-
 
Here is an interesting foot-note to this whole deal...........

Turbo 80's do not seem to have heating issues.........Guess which fan blade they have..........
















YUP, the stocker..............:rolleyes:
 
IdahoDoug said:
So, ya got a heat activated clutch in there already, right? You'd like to turn on the fan at the bottom of Vail pass on a 100 degree day with a trailer - right? Why not use HEAT to activate it? As in a cheap 12V electric radiant heat coil next to the fan coupling with an equally cheap bracket and a dash switch to turn it on and off.
DougM
Click to expand...

It maybe easier than that, the blue hub clutch is adjustable, the valve plate is held in by two screws in slotted grooves. By removing the cover and loosening the two screws the plate can be advanced to turn the clutch on sooner or retarded to delay it.

I just received some silicon oil and a new blue hub clutch (thanks Dan) so we will try to get some testing done in the next couple of days. Yes, the new clutch will be coming apart before is installed! What do I have to lose, it's Rob's! :D
 
You must log in or register to reply here.

Share this page

Back
Top Bottom