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

[nvrstuk]

Battling the heat issue with 105deg F temps, multiply that with low speed wheeling, well built 418 stroker and efficient heat removal is a priority... hence "The Torture Test"... at least here in the PNW...

I've spent literally dozens of hours studying and talking to Ron at Ron Davis radiators, Griffin tech dept, and reading excellent articles like BellaVista put together on Pirate....

With that, here's my simple test that I am working on to cure my heating issues. I learned a LOT from these experts that research these issues and solve them on a daily basis...

I run a brass/copper old school radiator that the core measures at 24.5"x18". With an Exploder front dress I run the Exploder clutch fan with a hand made fan shroud that the fan clears by 3/4" around it's circumference and protrudes into the shroud exactly 1/2 the depth of the blade.

I ran a simple back to back test comparing the Tauras fan with it's stock shroud and an Exploder clutch fan on this radiator. Both shrouds were fitted to the radiator. The Tauras fan shroud comes within 1/2" inch vertically (top and bottome) of covering the core and horizontally I have 3/4" of exposed core on each side. Ron said that ANY shroud must cover every row but it can only cover up to 70+% of the entire radiator (horizontally on a cross flow) and still be extremely efficient.

My custom Exploder shroud covers the entire radiator- both are sealed to the radiator.

So, I drove 20 miles up hill with the last 7 miles at 10-15 mph on a 10% grade in 105 deg F temperature. The first 15 miles of driving just got me to the grade and up to temp.

Results:


The Tauras fan allowed my temp to climb to 212deg F. and this was when I turned around yesterday at the base of the 7 mile climb...never finished the test yesterday since it was continuing to climb...

The Exploder fan allowed my temp to climb to 196 degrees and this was at the bottom of the steeper part of the grade (where I stopped yesterday) and stayed at that temp for the entire 7 mile steep climb at 10-15mph. I ended up picking up 6 teenagers 2/3 of the way up and they all climbed in the back(this was a stop on their West Coast skateboard/longboard tour-professional filming was happening...anyway) and my temp rose appr 2 more degrees with the extra weight. Every corner or every time I had to slow down to turn on one of the switchbacks, my temp would drop 2 or more degrees (just in the 15 seconds that I would let off the gas and turn).

Both fans allowed my Bronco to sit and idle for a long time without any temp increase at all. Put a load on the stroker and it's a different story.

For me, this shows that the Exploder fan draws more air than the Tauras fan does. I have two Mark VIII fans sitting on the shop floor but I have to modify the core support to try them for the test. Maybe some other day...

Here's the kicker. My old school radiator only drops the temp of the water coming in from the engine a WHOPPING 22-24 degrees! Everything I have read says the radiator should cool better and have a larger temperature drop from inlet to outlet.This was measured by an infared gun. Yup, that seems to be my biggest problem right there. Guess I'll try an aluminum radiator after the SEFI conversion is completed and move "stuff" out of the way so I can get even more surface area.

I'm looking at upgrading to an aluminum radiator since once they are constructed, they cool more efficiently than brass/copper radiators do.
I'm actually looking at a Raptor/F-150 (2013) radiator since they are sooooo wide and are relatively short height. 38"x15.5" perfect fit for my rig with a LOT more cooling surface area-almost 40% or more over stock.

Even though I ran the TC unlocked the entire way, my 4r70W tranny only got up to 150deg F since I have two coolers in line. One has it's own fan on it and of course it's mounted outside of the engine compartment (hot air trying to cool something isn't very efficient) and the other is a Super Duty tranny cooler which is mounted over the recommended distance from the radiator according to Ron Davis and Griffin...so long as you have over an inch btw them, air flow through the radiator is not an issue.

Guess I"ll stick with the mechanical fan and not have to worry about relays, wires melting, fan motors dying, etc... just a bit less to go wrong...

Hope this helps somebody.... have fun, go wheeling!

 

[Broncobowsher]

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.

The cool one now (starting to look into how to make it work) is a hybrid system. Mechanical fan, but electrically controlled. I know the fan clutch off a cummins dodge will screw right onto the Explorer waterpump (I posted pick of it a few years back). The fan is a different story. These take more work than just a thermostatic switch and a relay, even more than a variable speed fan controller. To properly control it there is a speed sensor on the fan clutch and a controller to watch that speed (and the engine speed, and various pressures and temps). The controller than changes the amount of lockup in the clutch. Neat stuff, but not in the hobbiest swap range yet.

 

[NicksTrix]

curious what core configuration did your copper rad have? row count, fin count per in and tube size? was this a new radiator?

interesting test. thanks for sharing

 

[TN1776]

Great test, great info. I run a pretty mild EFI 351w with an aluminum radiator and a 2500 CFM dual speed electric fan. The only time I ever over-heated was on a trail, when my old fan controller burnt up. I replaced it with a much better controller with two relays and have not had another problem (many years running this config) - however burning up that fan controller frightened me to the point where I still want to swap on the explorer front dress so that I can clear a clutch fan and big shroud. There is no equal, clutch fans absolutely pull more air through.

 

[nvrstuk]

Radiator was designed for a stock Ford 351W .... copper/brass...

13 fins per inch

2" deep...brass isn't usually made with cores more than 5/8...I'm guessing it's a 3 or 4 core.

It's actually a Ford Granada radiator designed for 351W back in the '70's....thought I'd try it since it fits my already modified mounts and is cheeeep... if this was alum and built with 1 or 1 1/4" alum fins I'm pretty sure it would keep my stroker cool since I ha e zero trou le at idle or crawling but more of an issue when I run at higher rpms (which usually coincides with more mph).

 

[toddz69]

Interesting test, Brian. My ol' truck (with Explorer dress) is running warmer and warmer each year. Not overheating, I guess, but I'm seeing a trend.

Todd Z.

 

[nvrstuk]

I admit after looking at my post, it's l o n g.... !! : ) but I really wanted to share an "apples to apples" comparison. Same temp, same everything, just different fan and shroud...

 

[badmuttstang]

Just curious which Taurus fan did you use the two speed or the single I thought the two speed put out the same cfm as the mark VIII. Great comparison by the way.

 

[nvrstuk]

Thanks, I used the 2 speed and had it on high, wired through a relay with a 40 amp fuse. No voltage loss and it was pulling 22.8amps.

Bench test btw the Tauras on high and the MarkVIII single speed (which is the highest flowing model) and the Mark VIII definitely puts out more air...

This was real accurate--- I had my hand and face behind the fans and compared them. : )

 

[badmuttstang]

Good to know for future reference. I do have a two speed can on mine same one Wildhorses sells and an aluminum radiator already with a 351 no issues but always good to know.

 

[chuzie]

Thanks for posting that info. Not enough data out there in general on this stuff.

I was researching recently and it seems the 94-95 Super Coupe has a cooling fan that has the motor of the MarkVII but a different blade design that pushes more air than a MarkVII. I purchased one but quickly realized the hub depth was too much without modifying the core support and didn't like the idea of relying solely on an electric fan, so now it lives in my shed with the rest of my collection of parts.

My explorer fan and ron davis radiator always struggled to keep the 351 cool during city driving and on the rocks. I did mod the core support and placed a volvo fan (smaller hub) in front of the radiator to act as a second stage when the mechanical fan can't do the job. It kicks in at 210*F. It has worked great and I am pleased to have finally gotten my cooling under control.

I set it up so I can bypass the temp sensor and force it on if the mechanical fan fails or off in the event of a water crossing. Also carry an extra motor for trail events.

 

[DanHall]

I assume this was the 4.0L Exploder set up?

 

[nvrstuk]

I tried a Ron Davis radiator years ago and sold it since it couldn't keep my rig cool. At the time I thought it was because of the fin count...

Why do we expect a radiator with a core area of appr. 320 sq inches to cool our rigs adequately? Heck, a basic Mustang for '79-93 core size is 440 sq inches and that's just for a 5.0... we're trying to cool 500HP strokers with one that's smaller!!

 

[allenfahey]

Great info and real world testing. I used to have a brass radiator and it couldn't keep cool. I now have the explorer front dress but used a 95 V6 Explorer radiator. It's a great combo that cost me less than $120. This past weekend at the MEB Roundup it never got above 195 degrees with a 190 degree thermostat in the three days we wheeled.

 

[nvrstuk]

The next "Heat Torture Test" is going to be floorboard and tunnel temps! OUCH!!! My floorboards and tunnel the past two days during my fan tests have ranged in temps from 123deg F to 147deg F... no wonder my wife always wanted to ride in the back seat on our 14+hr one way fishing trips up to British Columbia... we packed spray bottles, would jump in the Columbia River or some lake a couple times along the way...guess we were tough back then!

Anyway back on topic... : ) I currently run BC Broncos S/S coated shorty headers I have foil backed insulation on my firewall (in an attempt to reduce heat for my wife 20 years ago!)...

I will start a new thread and update it as I go along. I plan several stages. 1st step is to wrap my 2.5" exhaust on each side all the way back to my mufflers...yeah, it will accelerate replacement but if I die of heat before the pipe rusts out, who cares...right?

Update- July 2017-

I am rebuilding my Bronco front and rear ends, exhaust, suspension (completely).
I will be running 3" duals but hope to build in heat shields around the pipes and mufflers (which could be mounted under the seats as I lowered floor on DS and raised floor on PS by 2" which gives plenty of room for a 5x22" body muffler)... I will see how it works out and post it up...

May 2018 update...the floor is COOL (er)...MUCH cooler...I will try to post up my results but it is MUCH cooler in the cab.

 

[galen1970b]

Ditch the stock waterpump and get the flowkooler waterpump WH sells. It will save you time and money trying to adapt a raptor radiator. I'm in Arizona at the moment and was fighting 230+ temps on my rig while towing a 5x8 trailer(and I couldnt even turn my A/C on...). I'm using a champion 3 core aluminum radiator. I spaced my fan shroud out an inch so the fan is in an inch or so.(sealed the gaps with aluminum tape in the mean time..) After installing that waterpump on my explorer serp setup(with a new fan clutch to boot..) My truck has yet see over 195 with the A/C on in the midday heat(it was 109 today). Its crossed my mind now that when I get my truck up to washington this week(Yep! road trip!!) Ill have to install a hotter thermostat before summer is out.

 

[toddz69]

Ditch the stock waterpump and get the flowkooler waterpump WH sells. It will save you time and money trying to adapt a raptor radiator. I'm in Arizona at the moment and was fighting 230+ temps on my rig while towing a 5x8 trailer(and I couldnt even turn my A/C on...). I'm using a champion 3 core aluminum radiator. I spaced my fan shroud out an inch so the fan is in an inch or so.(sealed the gaps with aluminum tape in the mean time..) After installing that waterpump on my explorer serp setup(with a new fan clutch to boot..) My truck has yet see over 195 with the A/C on in the midday heat(it was 109 today). Its crossed my mind now that when I get my truck up to washington this week(Yep! road trip!!) Ill have to install a hotter thermostat before summer is out.

Galen: What kind of condition was your water pump in that you removed from your truck? Any visible corrosion on the impeller blades or anything else that might provide clues to its performance? I'm surprised (but pleased) that the Flowkooler made that much difference. It's my understanding that the stock Explorer water pump/timing cover cavity shape essentially mimic the design of the Flowkooler?

Thanks,
Todd Z.

 

[galen1970b]

Galen: What kind of condition was your water pump in that you removed from your truck? Any visible corrosion on the impeller blades or anything else that might provide clues to its performance? I'm surprised (but pleased) that the Flowkooler made that much difference. It's my understanding that the stock Explorer water pump/timing cover cavity shape essentially mimic the design of the Flowkooler?

Thanks,
Todd Z.

My water pump was only maybe 1 year and a half old and it spent 7 months sitting due to a deployment. It was in good shape when I pulled it off so I decided to keep it in case a manufacturers defect crops up. I wish I had taken some detailed pictures of the flowkoolers impeller vs the stock one....its a night and day difference. Flowkooler has a nice billet anodized aluminum impeller that has nice curved blades, where the stock pump is made from a stamped steel, strait blades, not very good clearances etc.. Now, before I installed the A/C system with the stock pump and the champion radiator my temps were also down in the 190s, never breaking 200 even on hot muggy arkansas summer days wheelin. The condensor pretty much blankets the entire front of the radiator and restricts airflow driving my temps up.

 

[nvrstuk]

Interesting results on the flowkooler pump install. Galen- what engine are you running?

I went with a new Motorcraft pump after both national radiator firms said they were the "best" affordable pump. I believe ntqsd is running one of the other recommended brands but it was over 300 bucks when I checked into it...anyway... wish maybe I'd tried the flowkooler now....

Here's a test that Ron Davis does with most of the difficult cooling problem vehicles. They pressure test the wtr pump with the t-stat in BUT immediately upon start up so the radiator cap which is removed isn't building any pressure, just the pump.

At idle you get zero pressure all the way to about 1600rpm, then the pressure builds so at 2200rpm you should have appr 14# of pressure in the block. Maybe your flowkooler pump is pressurizing the block that much sooner and better than a stock Motorcraft pump. The Chebby small block pumps put out even more pressure than SBF's... that's what I was told anyway.

Thanks for adding that bit of info Galen! It seems to back up the "block pressure" theory that the more pressure the block has in it, the better the heat transfer is. Then it's up to the radiator to cool what the pump is sending it.

Reason I asked about your engine size is back in the day of running a semi-stock 351W, I ran cardboard in front of my radiator literally from Nov- thru April JUST to get the engine up to temp while running an old skool Duff 4 core. (no-I'm not exaggerating- I remember noticing my temp gauge once at 200F while pulling our 18' boat up a 10 mile long hill on a 95degree May day and thought OH-CRUD, the cardboard is still in front of the radiator!- pulled it out and continued...) This was also pulling trailers thru AZ, NM, CO, E.WA, etc during 100 degree days.... engine displacement has forced me to up the radiator capacity to match the horsepower output that has doubled since those days.

 

[galen1970b]

Im running a tired 302. Only mods are the performer rpm intake...bcb headers/exhaust and a lot of TLC... It has some minor blowby when hard accelerating but thats about it. I think you are little off about the pressure though...the system is pressurizing because of the heat not the speed of the pump....its a flow/volume thing...the flowkooler is doubling the amount of coolant between the sink and the source between idle and 3k rpms....and thats whats dropping my temps so much.....but it was 100 bucks for the waterpump....cant beeat that!