Radiator fan debacle....

[BPerry]

So, without the support group I have likely made a slew of bad decisions... Lol
This will be a long one... Gotta catch up!!

Particulars = 351W, New 4 core rad "not Aluminum", new shroud, PO's 16" flex fan, PO's 16" pusher elec fan (PO has cut the lower horizonal support to accommodate this).

Temp likes to sit between 203-208 while driving at 0 grade (which is fine), starts climbing with any fluctuation in grade or pull on the motor "mind you with 5.13's she is running 2850 ish RPM's at 55mph", bring her down to 2400-2500 and that's where she wants to be. This is why I'm moving to 3.89's or 4.11's, that rpm range seems to be the sweet spot.

All good right, change the gears and be a happy camper! Nope, I live in Arkansas, it gets hot... I understand a stationary rig is going to warm up (especially with the motor is locked up in a tin can with no room to put a toothpick in), but I have to account for this somehow right! So, stationary she just climbs until I'm in motion, I know this is going to happen; I just want to do what I can...

Before I go into the below, let me say! I do NOT like cutting crap off.....

I acquired a new 6 blade 17" fixed fan in plans to ditch the flex fan and keep the pusher fan. Nope, needs a 1.5" spacer to clear the A/C pulley and this puts lower blade rotation all up in the radiator.

So, fling the new fan and go to a shrouded 2 speed elec puller fan! "No" I did not account for the alignment nipple. I need 4" of clearance with the fan mounted externally and 3.5" if I mount the electric fan inside the shroud (this will take some fab work, but I have that figured out). Again, Nope; I've laid under the thing for two nights just looking and thinking....

Here is what I'm gonna do, so ya'll tell me if I'm about to make a mistake!!

Back to the fixed fan, Cut off most of the inside upper radiator support channel (this will allow for the angle change). Cut off what is left of the lower horizonal radiator support (this would include the lower radiator mounts). I already have fabricated 2 pieces of 4" angle iron 6" long, planning on mounting these to the Frame using existing factory holes. Reusing the factory lower mounts with the new brackets attached to the Frame.

In doing this all measurements will work and the rad actually should be in angle alignment with the motor.... Still leaving room up front for the later date A/C install or two small pusher fans if need be!

AM I making a mistake with the Frame mount????

Glad we are back up and running, happy Friday good people!!

BP

 

[SteveL]

I didn't have good luck with the 4-core radiator. I'm also running 351w's. I've got the beefier bc 3-core in both broncos. They bolt right in the stock brackets. I've heard bc no longer stocks em but driven auto parts does. I also run the steel shrouds from Tom's to accommodate the body lifts. Other than that the cooling set-ups on both are stock eb parts. I drive em in so cal traffic with no problems.

 

[Timmy390]

Trying to understand.....why the change is needed? 203-208 is all good. Guessing a 190 stat or 195. There are owners here that would give up a kidney for those temps. AR is only slightly hotter than the earths core.

My rig runs 200-220 (low end I winter high end in summer) running a 195 stat. The 220 is when the high speed on the fan kicks in and cools it back down to 210.

The stock radiator mounts have the radiator leaned in at the top. You CAN move the upper mounts to the outside of the core support and get more room. I did this to make the van front dress fit. I run a 17 inch derale fan (the one WH sells) and it only needs 2.7 inches of clearance. Mounted it to my Champion American Eagle radiator with no issues.

Tim

 

[BPerry]

Trying to understand.....why the change is needed? 203-208 is all good. Guessing a 190 stat or 195. There are owners here that would give up a kidney for those temps. AR is only slightly hotter than the earths core.

My rig runs 200-220 (low end I winter high end in summer) running a 195 stat. The 220 is when the high speed on the fan kicks in and cools it back down to 210.

The stock radiator mounts have the radiator leaned in at the top. You CAN move the upper mounts to the outside of the core support and get more room. I did this to make the van front dress fit. I run a 17 inch derale fan (the one WH sells) and it only needs 2.7 inches of clearance. Mounted it to my Champion American Eagle radiator with no issues.

Tim

Hey Tim,

I'm perfectly fine with the 203-208 and even the rise with engine load, currently I have a 180 RS tstat installed.

I don't like the idle rise, I know I won't be able to completely get away from it; but want to help it along a bit.

A 17" Mechanical Derale is what I'm installing. Top radiator spacing is not the issue, clears just fine. It's the bottom... I'm having to use a 1.5" spacer to clear the A/C pulley, with this the bottom of the fan contacts the radiator.

With the radiator in the stock position, I have just under 2.5" of clearance from the alignment nipple.

I could change the pulley, but I will eventually re install A/C; so might as well make it work now.

Yes, I could go with a non-shroud elec fan, did you run into any contact issues with the core support or hood clearance when moving outside the core support. I studied on that...

BP

 

[Timmy390]

OK got it....so it's the front dress that's the issue....Hummm...I like spending other peoples money so I say, Go Explorer front dress and be done with it IF the AC compressor will mount up or swap to Explorer compressor (I plan to run a van compressor at some point) That E-front dress cools like a son of a gun and it all fits. Do have to deal with the balancer issue 3 bolt vs 4 but so many have done it. I should have but was money strapped at the time of my conversion and mad do with what I had.

Tim

 

[DirtDonk]

Two things.
One is ditto what Timmy said and if it's going to take you all sorts of modifications and mocking up, you might as well spend time sourcing an Explorer front accessory drive.
Best clearance, best accessories, best fan.

Two is do you know for sure exactly what temperature you are running? I know the gauge says just above 200, but do you KNOW for a fact that the gauge is reading correctly? Even within ten degrees is decent, but enough to put you on the hunt where if it was actually 193 instead, you would likely not be having this conversation. Only a ten degree difference...

Ok, and three...
Where is the temperature probe/sensor/thingy installed? Factory position? Or somewhere else?

Paul

 

[DirtDonk]

Oh, and number four...
When you're idling and the temp is going up, does the electric fan come on?
If it does and you're not cooling down then it sounds like a water flow issue. If the fan is not coming on, then find out why and set the temperature threshold lower if you can.

Paul

 

[Yeller]

I'll chime in...... ignition timing is critical as well. X a million on the Exploder front dress, solves all cooling issues as long as ignition timing is correct. Another easier option that hasn't been mentioned that seems to have good success is get the 6 blade fan that Vintage Air sells with their AC kit, it works well, clears the compressor and has a good track record.

With proper ignition timing, and everything else working as it should, temperature rise at idle should be all but a non issue.

as a side note aftermarket automotive gauges are notoriously inaccurate and inconsistent, mechanical ones are a little better but still not great. Sad, I can buy a calibrated, liquid filled industrial gage for 1/2 of what a big name automotive crap gage costs.

 

[BPerry]

OK got it....so it's the front dress that's the issue....Hummm...I like spending other peoples money so I say, Go Explorer front dress and be done with it IF the AC compressor will mount up or swap to Explorer compressor (I plan to run a van compressor at some point) That E-front dress cools like a son of a gun and it all fits. Do have to deal with the balancer issue 3 bolt vs 4 but so many have done it. I should have but was money strapped at the time of my conversion and mad do with what I had.

Tim

I stopped keeping track of what I'm spending long ago!!! Lol

 

[BPerry]

Two things.
One is ditto what Timmy said and if it's going to take you all sorts of modifications and mocking up, you might as well spend time sourcing an Explorer front accessory drive.
Best clearance, best accessories, best fan.

Two is do you know for sure exactly what temperature you are running? I know the gauge says just above 200, but do you KNOW for a fact that the gauge is reading correctly? Even within ten degrees is decent, but enough to put you on the hunt where if it was actually 193 instead, you would likely not be having this conversation. Only a ten degree difference...

Ok, and three...
Where is the temperature probe/sensor/thingy installed? Factory position? Or somewhere else?

Paul

Hey Paul,

I will be all in on my mods for less than $100...

I have three points of temp verification, the sniper is just behind the tstat (I know this will show warmer), second is the factory gauge (5 deg cooler ish), third is a heat gun taken at multiple points (hits right in the middle).

 

[BPerry]

Oh, and number four...
When you're idling and the temp is going up, does the electric fan come on?
If it does and you're not cooling down then it sounds like a water flow issue. If the fan is not coming on, then find out why and set the temperature threshold lower if you can.

Paul

Yes, the elec fan is controlled by the sniper. Kicks on at 195, holds for jus a bit an then climbs.

I can also manually engage the fan, I let it warm up to 213, hit the fan; it will bring it down a few deg, the starts moving back.

 

[BPerry]

I'll chime in...... ignition timing is critical as well. X a million on the Exploder front dress, solves all cooling issues as long as ignition timing is correct. Another easier option that hasn't been mentioned that seems to have good success is get the 6 blade fan that Vintage Air sells with their AC kit, it works well, clears the compressor and has a good track record.

With proper ignition timing, and everything else working as it should, temperature rise at idle should be all but a non issue.

as a side note aftermarket automotive gauges are notoriously inaccurate and inconsistent, mechanical ones are a little better but still not great. Sad, I can buy a calibrated, liquid filled industrial gage for 1/2 of what a big name automotive crap gage costs.

Hey Yeller,

I've played with the idle timing to the point where there is no positive effects. Worse yes... lol

 

[BPerry]

As mentioned, under power at 2400-2500 (fan engaged) with no uphill or acceleration load she will hold firm.

 

[Yeller]

Hey Yeller,

I've played with the idle timing to the point where there is no positive effects. Worse yes... lol

Ok another timing question. The vacuum advance is working correctly? If not it will have major cooling issues at low speed/low RPM.

 

[BPerry]

Ok another timing question. The vacuum advance is working correctly? If not it will have major cooling issues at low speed/low RPM.

No vac, I'm running a complete Sniper install.

That's why I can play with the time very easily!

 

[DirtDonk]

What is the age of the engine? Age of water pump? Just curious in the way of adding more details.

When mine was almost all stock (engine bone stock, Bronco lightly modified) it would run all day long at thermostat temp. When I was either on a tight technical trail, or the highway for more than a half an hour or so at 70mph (at 3,000 to 3,500 rpm level just above where yours starts to run hotter it sounds like?), it would creep up 20-25 degrees. Those were the only two times.
Never really found out what would do it, but it never really hurt anything either, since it did not go higher. It did not seem to be cavitation in the pump, but it did get more consistent and creep up over a narrower range after I installed an early Flowkooler water pump.
It could easily have been airflow, being that both situations (low speed and much higher speed) are the bane of a Bronco's aerodynamic happy place). Low speed has the stock fan not moving much air, and high speed building up high-pressure under the vehicle and impeding flow through the radiator. Bronco aero is not your friend usually.

Which is why I was curious what happens when your electric fan comes on at idle. With no load on the engine and good air flow through the radiator, that leans more towards low liquid flow through the radiator. Does it cool down while sitting when you rev the engine up?
And you're sure that, as a pusher, the electric fan is blowing the the correct direction?

Just checking...

Paul

 

[BPerry]

Well, it's all over but the crying...

It ain't pretty, it ain't professional.... Functional maybe???

Been idling in the driveway for 15 minutes or so and didn't crack 195...

Pulls at least 3 times the air as before, now to clean up my brackets, put some welds on and call it a win!

 

[DirtDonk]

Hmm, a 351 that runs hot... Sounds kind of familiar.
Was the engine over-bored at some point? If so, by how much? And what about the cam? How much of a performance cam is it?

paul

 

[DirtDonk]

Fantastic! So the new fan position was all it took? Which fan did you end up using?
My next questions were going to be about air pockets. But that seems to be moot at this point.
You can start crying now, but they may be replaced by tears of joy if it runs good at both extremes and keeps a steady temp.

Congrats!

Paul

 

[DirtDonk]

Ok, now looking at the pics, did you only cut the shroud? Or did you reposition the radiator?
Or both?