Heat torture cooling system test... Exploder mech vrs Tauras electric fans...

[DirtDonk]

I always thought they were both.
I don't think 73AZ's specs were to indicate that there was no thermal property to the clutch. Just that different ones had different lockup vs speed properties as well.

Paul

 

[bronconut73]

Summit sells both a thermal type and a viscous type.
One is temp the other is based on rpm.
Maybe that's the difference.

 

[DirtDonk]

Even the viscous rpm-based ones use temperature in addition to anything else. The fluid inside the coupling gets thicker and more resistant to slippage when it's hot vs when it's cold.

They likely do work differently at different rpm levels, but still have that thermal aspect.
At least as far as I know. I know there are some that are completely computer controlled, so not the same as what we're talking about. But even in those cases, the computer is simply making the clutch react to temperatures.

I bet there's a white paper, or better yet, a discussion in English(!) on just exactly how the designs work. I'm not going to take time to hunt one down today, but now I'm really interested in seeing how they're engineered and what criteria they all look at during their function stages.

Paul

 

[73azbronco]

Sorry to confuse. Clarification, yes, the clutches use the heat to thermally adjust the drag inside the unit.

The more heat, the more drag, which increases RPM output of the fan as a percentage of input based on the design. I'd say like a torque converter but those do not change based on heat, just rpm. The fan clutch uses bimetalic device internally to increase or decrease the friction. i say internally but some have that round springy looking device on the face of a clutch, thats what moves and adjusts the friction. Truck clutches have a higher "lock up" percentage than auto clutches. Truck clutches will move more air when they get hot than passengers fans, upwards of 90% of the motor rpm. The plastic fan is used on the smaller 4 liter motor and has the lower duty clutch, only locking up to provide about 70% of the engine RPM.

On the fan blade design of odd or even, its most likely to control noise, not vibration. If they had even blade numbers the fan would be noisier.

 

[bronconut73]

{ The plastic fan is used on the smaller 4 liter motor and has the lower duty clutch, only locking up to provide about 70% of the engine RPM.}

The 5.0 serp. stuff I got from Sandmann has the plastic fan on it. I like it. Looks like it will move gobs of air but is uber light too.

 

[73azbronco]

I'm just going off my numerous visits to the junkyard, all the 5.0's had steel fans the 4 liters had plastic. Not saying a 5.0 never had plastic, but if they did they might not be the heavy duty towing package versions with HD clutch. Bolt pattern size is different steel to plastic, and I found out the difference going though the catalogs realizing the plastic fan clutch was not heavy duty. In fact, any replacement fan you find that is plastic, specifically warns you not to use it for offroad purposes.

 

[sanndmann3]

The 5.0 Explorers had both steel and plastic fans. From my recollection, the 96-98 (ish) had the steel fans. Later ones plastic. I'm guessing cost and weight were the reasons for the change...

 

[toddz69]

Rockauto isn't necessarily the end-all when it comes to figuring stuff like this out but it's handy to check it for reference. They list the same fan clutch PN for all years of 5.0s from 96-01 and they list steel fans for 96-98 and plastic ones for 98-01, with 98 apparently being a crossover year. I look at dozens of Explorer 5.0s in the yards (looked at a few again today) but rarely pay attention to which fan is in them.

Todd Z.

 

[ntsqd]

FWIW vibration is noise. You may or may not be able to hear it, but it is.

The lighter clutch and fan are good for the water pump bearings' longevity.

I'd be interested in a white paper on clutch fan clutches. My Toyotas have a threaded plug in them, can buy the silicone (?) fluid from the stealership to refill them.

 

[73azbronco]

My info is from the manufacture of the fans and clutches. Forget their name right now.

 

[nvrstuk]

Since we have a question about not having a comparison between electric and mechanical...I'll bump this back into circulation

 

[chuzie]

Not sure if I mentioned this already but I found a decent increase in performance in my recent iteration.

Old was Volvo fan (no shroud) in front and explorer mech in back w/shroud. Temps exceed 210 in summer traffic.

New is just Volvo fan w/shroud on back only. Hasn't exceeded 210 yet.

Sent from my SAMSUNG-SM-G930A using Tapatalk

 

[ntsqd]

Not the first time that I heard of removing a pusher electric fan to cool the engine better.

 

[nvrstuk]

I'll post what I had to do in order to get my floors cool as I was comparing and checking fan outputs...

Floors always got hot from the day we got it...June 28,1976.

Things tried in order to cool the floors in order-

I tried heat mat on the firewall and floors back in the '80's. I put 2 layers of jute backing under carpet...

I put a body lift in

I ceramic coated the headers

I put dynamat in

I wrapped the headers AND exhaust to the mufflers behind the frt seats.

When I did my suspension build in '17 I put alum sheets spaced 1/2" off the firewall and the floor. This ONE change did more than ALL the others combined... almost unbelievable difference.

Multiple readings on the console and passenger floor...temps were from 148- 149 deg F on a 100 deg day.

After putting alum sheets on the firewall from the top of the heads down and underneath the floor pans to behind the seats the console amd floor temps dropped to 102 deg F on a similar 100 deg F day after driving around for 40 minutes... this is with the dual mufflers mounted directly under the seats.

 

[toddz69]

When I did my suspension build in '17 I put alum sheets spaced 1/2" off the firewall and the floor. This ONE change did more than ALL the others combined... almost unbelievable difference.

Multiple readings on the console and passenger floor...temps were from 148- 149 deg F on a 100 deg day.

After putting alum sheets on the firewall from the top of the heads down and underneath the floor pans to behind the seats the console amd floor temps dropped to 102 deg F on a similar 100 deg F day after driving around for 40 minutes... this is with the dual mufflers mounted directly under the seats.

I know Jonathan Ward does this on the ICON Broncos as well. Lars did it on his Bronco and he said he got excellent results with it too. I plan to eventually put some spaced cookie sheets on mine too .

Todd Z.

 

[ntsqd]

What I've learned from doing it that an air gap is good, but airflow thru that gap is much better. I recently did this using, ironically, aluminum heat shielding from the power plant to keep exhaust heat off the Puma compressor under the 4rnnr. The shield is 1/8 of the distance from the muffler that the frame rail is, yet after ~30 mins of fwy driving the shield is considerably cooler than the frame rail itself. In this particular arrangement the airflow is technically on the wrong side of the shield, yet it works very well.

 

[nvrstuk]

Absolutely TS- air flow is the key. Thats why my 1/2" sq tubing spacers run front to back to aid air flow when crawling or flying... ;-)

 

[73azbronco]

I completely believe it. A well engineered mechanical fan is hard to beat. Always has been. There are reasons they are still used in heavy duty applications.
.

Add, with heavy duty clutch designed to lock up, not spin at 60-80% like passenger cars use to make them quieter.

 

[nvrstuk]

So Todd Z. the steel Exploder fans were only available from '96-98? I've been running plastic all these years... would upgrade f I could...plastics seem to crack eventually...

 

[toddz69]

So Todd Z. the steel Exploder fans were only available from '96-98?

I think that's what sounds right. I've just used plastics myself too. Mine has been in there since '07 and seems to be surviving just fine.

Todd Z.