Best Explorer Fan Clutch?

[gclauson]

Update: the replacement NAPA fan clutch works exactly the same as the previous. Doesn't seem to lock up and coolant temps rise above 220 (before I shut off).

Perhaps the fan clutches are working as designed and I have an airflow issue thru the radiator? It is a Griffin Bronco-specific aluminum radiator. It has two wide rows of tubes, making it as thick as a four-core brass radiator.

I also have the Explorer 5.0 Flow Kooler water pump and a high-flow thermostat.

I have added seals between the core support and radiator on the sides and bottom and have cardboard versions of the SS air dams between the core support and grill, so engine bay air should not be cycling back into the radiator.
2" body lift should allow air to escape the engine bay better than no body lift.
My hood and prop rod get so hot that I can't open the hood without using a cloth rag for a "hot pad". Seems like the hot air is just pooling in the engine bay.
The air inlet temps (reading from the OBDII) rise to 170 degrees, so the under-hood temps are getting up there.

It runs right at thermostat temp (195) when driving at any speed above 30 mph and doesn't overheat at highway speeds; it is low-speed traffic and trails where the temps climb.

Any new comments? Does anyone else have issue with the Griffin radiator?

Thanks!

 

[EPB72]

you will most likely never get the fan clutch to lock up if you don't have AC . or you live in death valley on a 125 degree day...maybe? the condenser is what adds the heat for the fan clutch to engage..

 

[toddz69]

I was going to chime in and note that I've never been able to get my clutch to lock up either and it gets pretty darn hot here in Phx.

Todd Z.

 

[gclauson]

Thanks, guys. I'll go down the path that the Griffin might not be great. I read somewhere that some fin/tube configuration of aluminum radiators is sub-optimal, but don't know if Griffin lies in the "good" or "bad" design.

 

[73azbronco]

Mine locks at 105 outside warmed up, 195 thermostat. Clutch should lock by about 195. It's bad or wrong one if not.

https://www.google.com/search?q=aut...#fpstate=ive&vld=cid:c32b1b90,vid:QVMN7LmKLYA

 

[stretch]

Just a general observation. I have the explorer accessories/ fan. When I was finishing my build, I noticed that the stock explorer fan clutch was weeping a little oil around the bearing. I took the opportunity to upgrade to the heavy duty clutch. It took a while to getting around to installing the new clutch, but as soon as I did my temps spiked to 220. Been running 203-205 consistently on the same stretch of road/ambient temp. I also noticed that everything I touched inside the engine bay was now heat soaked with this new setup.
What changed? The only real difference I could tell was the hd wasn’t as noisy and it set into the fan shroud deeper, or closer to the radiator. Unlike the original setup that stuck out approx. 1/4” outside the shroud. The old setup also blew a significant amount of air through the engine bay vs the new. I have since swapped back to the original and my temps are back down to 203-205.

 

[36Fan]

On my 347. Explorer front dress, 18" stock plastic fan and clutch, 4.0 v6 Explorer radiator, Ron Davis shroud set up. The fan is 2" from the radiator, 5/8-3/4 gap on the circumference, fan depth is roughly 3/4 way inside the leading edge of the shroud. Stock 192 thermostat, never runs hot. I don't remember hearing the clutch kick in, but Id imagine it has to be somewhat.

 

[gclauson]

Thanks for those three updates.
Before I spend big bucks on a new radiator, I will mock up a different fan shroud. Currently, with the Griffin radiator that is a thick as a four-core, and the Ron Davis aluminum fan shroud, my fan is almost all the way inside the shroud (perhaps 1/2" of the blades are exposed).
I will make a shroud where the fan blades are halfway exposed and see if things improve.

 

[DirtDonk]

You can mess with the spacer thickness too, if you are actually using a spacer. But did you say that your fan blade edges are already pretty close to hitting some things on the engine? Including the belt?
We see that a lot even with standard setups, where the spacer is as thin as it can get for radiator clearance. Any thinner and it starts to get too close for comfort to things like power steering pulleys and such.

Paul

 

[ba123]

man....sooooo many people talk smack around here about electric fans and now we see how it really is. You guys just want the rest of us to join in your misery!!!

(ok, after saying that, I hope my electric fan works out...I don't have room for anything else anyway).

 

[36Fan]

man....sooooo many people talk smack around here about electric fans and now we see how it really is. You guys just want the rest of us to join in your misery!!!

(ok, after saying that, I hope my electric fan works out...I don't have room for anything else anyway).

Hahaha... I actually run both, electric Ford Mark 8 fans, and Spal fans with Volvo relay units on my desert trucks. Clutch fans on my Broncos, both have their place and work well if they are set up correctly.

 

[ba123]

Hahaha... I actually run both, electric Ford Mark 8 fans, and Spal fans with Volvo relay units on my desert trucks. Clutch fans on my Broncos, both have their place and work well if they are set up correctly.

sorry to hijak but I just test fitted my very slim electric fan. 3.1” WITH my shroud!

I’ll be screwed if this doesn’t keep it cool enough.

 

[gclauson]

Hey Paul,
I have the Exploder front dress, so no spacers to add or subtract.
I hope to build my cardboard mock-up fan shroud over the weekend.

 

[DirtDonk]

Yeah, I knew that! Ha ha, sorry I forgot which discussion we were in.
Just a momentary lapse of reason…

 

[gclauson]

Rather than make a cardboard mock-up fan shroud, I removed 9/16" from the circular part of the shroud, exposing the Explorer steel fan blades about halfway.
No change. Idling in my driveway with 85 degree air temp, it went from 198 to 230 in 7 minutes with no sign of stopping.
It just seems like very little air flow. Hood and prop rod are too hot to touch w/o a thick rag for protection.

I forgot to mention earlier, I also have a pusher fan, about 12-14" diameter. When it is on, can barely feel air thru the radiator core and it seems to blow quite well for the size. Points to the Griffin core having too many fins or tubes, blocking airflow too much?

Gonna try to add airflow during idle with my leaf blower!

 

[DirtDonk]

Sounds like a good test!
And it sure does seem like something is blocking flow. An explorer fan by itself should be pulling all sorts of air.
The pusher fan, while the vehicle is sitting still, should just add that much more.

It’s the same with hood open vs closed?

 

[gclauson]

Latest update:
I did not do the leaf blower cooling experiment.

Paul, it does drop about 5 degrees if I open the hood.
I also noticed a lot of hot air blowing upwards in the gap between the core support top of the radiator, so I closed that with aluminum duct tape.

And, have added more timing to the Explorer OBD tune (thanks, Garry!)

Did a hard off-road trail that climbed from about 45 minutes of 6000 to 7000 ft of first gear, low range crawling and the coolant temp never exceeded 205, whereas is used to have gone past 220. Air temp was about 75-80 degrees.

So, I'm tentatively hopeful. Will test it more at the Buena Vista Super Cel in September.

To summarize the current solution (some of which not discussed above):
- new Four Seasons Explorer 5.0 fan clutch
- Explorer front dress
- Flow Kooler water pump
- rubber seals between core support and the sides and bottom of radiator
- aluminum duct tape at top of radiator
- carboard version of the stainless air dams between core support and grill
- rubber seals between bottom of core support and grill
- rubber seal along top edge of core support to the bottom of the hood front brace
- metal plugs in the extraneous holes on passenger side of core support
- 9/16" cut off circular part of Ron Davis aluminum fan shroud to expose about half of the cooling fan blades
- Griffin aluminum Bronco radiator with reversed outlets to match Explorer front dress
- standard 50/50 Prestone coolant
- 12" pusher fan (not used in above trail test}
- 195 degree thermostat
- increased timing advance

Fixes centered around ensuring only cool air from front of the truck enters radiator and prevention of hot under-hood air circulating forward and re-entering radiator. (Truck doesn't have cooling issues at highway speeds.)

 

[DirtDonk]

So far so good! Thanks for the update. I think we all appreciate it.