can an electric fan cool my ride?

[dkn1997]

I have been subscribing to a thread by hpproron titled "clutch vs. flex fan" and it got me thinking....

Is there any way that I could measure airflow (cfm) through my radiator with my fixed fan? the reason is that I would rather be running an electric, but the 2100 cfm one I had would not do it.

If I could determine the flow of my current setup (car runs cool) maybe I could get an electric that is the same. Or would it be better to step up to the absolute biggest (most cfm) that I could find?

I heard that Spal makes very good fans and that thiers are the only ones that truly flow what they advertise, anyone have experience with this?

also, are two small fans better than one big one? I have a be cool direct fit rad with 22" of core space, so that's what I have to work with

thanks, kevin

[tsteiner61]

If your electrical system can handle it, I would step up to the big boy fan. You said your fan is 2100 cfm, is it that Summit fan? If so, that's the same one I have and it is a POS! I've been having major cooling problems with my 408 and am going to replace that thing with a bigger fan soon with Summer fast approaching. I should've known better than to buy it as there is an ad on the same page of the Summit catalog advertising a 2800 cfm fan and saying that fan is only good to 260hp. I'm going to go with as much fan as will fit and I can afford. Judging by those numbers I will try to go 4000 cfm if I can find one.

Do you have a website for spal fans?

Thanks.

[charger_dan]

Hey Kevin, Dan here.
I've gone down this same road with cooling my Dodge. Here's what I've learned:

- 95% of all electric fans on the market are crap. Fans by Mr. Gasket, Flex-A-Lite, Perma-Cool, etc. are marketed to the street rod crowd, and thusly, are designed to "cool" a 350 Chubby motor. They're toys. Save up your money to buy some real fans.

- SPAL fans are killer. Designed for continuous duty use. Huge motors, sturdy construction, efficient blade design. Designed in Italy, SPAL fans are OEM equipment on many of Europe's finest high performance cars (Ferrari, etc.). They cost about twice as much as a street rod "toy" fan, but you definitely get what you pay for.

- Electric fans, like Monica Lewinsky, do their best job when they suck. Mounting fans at the front of the radiator creates an airflow restriction at freeway speeds, and with a properly-sized radiator, you won't need fan airflow at freeway speeds anyway.

- As for hard numbers, when cooling a big block Mopar with electric fans, shoot for a minimum of 3,400-3,500 CFM of airflow. Go with more if you can swing it. Vintage Air sells a single fan that flows 3,700+ CFM. It's a monster. You can never have too much airflow.

- Dual fans are an excellent idea, especially if you don't plan to fab a shroud. Also, with dual fans you avoid clearance issues between the fan motor and water pump pulley snout. Dual fans help pull air through the core over a larger area = more efficient cooling.

- On the radiator: you want to maximize surface area, not depth. This will also give you max room for big fans. I broke out the Sawzall and opened up my core support to fit my alum. radiator and have been glad I did.

- Comparing mech. fan to electric: I too tried to get some CFM numbers on mech fans for comparison to electric fans, but came up with nothing.

- Big advantage of electric: max rpm and CFM at idle. Not so with engine driven fans. You'll appreciate this in the staging lanes on a hot day.

- Wiring: always use relays - one per fan. Use a thermostatic switch to control the fans, with a manual on/off toggle switch for manual cut-in when you need it. Painless Wiring makes a great thermo sensor and relay kit. Circuit protection with fusible link or circuit breakers is mandatory for safety.

What I'm running: (see picture)
Howe 31" x 19" universal alum. radiator. 2 rows of 1" tubes.
Dual SPAL 13" high performance puller fans. 3,420 CFM airflow.
FlowKooler water pump, Robertshaw hi-flow 180 thermostat.
Painless thermo fan switch, relays, circuit breaker protection.

Websites:
http://www.spal-usa.com
http://www.vintageair.com (sells SPAL fans)
http://www.racerpartswholesale.com (where I got my SPAL fans)

I've been real happy with my combination, and it has proven to be very reliable and effective at cooling my 440. Bear in mind Oregon summer temps rarely get above 95-100 degrees.

Sorry so long. Just hate to see others waste their money and time to learn what I already have learned the hard way.

Good luck!

[fastmopars .inc]

wow, im so sorry i didn't get to you guys first.
i went and picked up a set of electric fans from a 3.8L ford windstar. i don't have any hard numbers, but on my 11 second 440 satellite with 10:1 and iron heads, the first stage sucks enough air to cool the engine. it is a two fanned system, with a 12 inch and a 14 inch fan, and when the 14 inch fan kicks in it will cool the motor right down to the thermostat opening point. i paid about 50 bucks canadian for two sets of fans.
they come factory with a shroud too!

[rdrunner1974]

What do you have for radiator? If it was a 318 and you now have 440, did you change it. I had a cooling problem with my Roadrunner, put in electric fan which helped but still runs hot on hot days.
I have a 2 core radiator in it, but bought a 3 core last fall.I will be putting it in next week .
My son in law had comparible problems with his 67 Chevelle, we put in an alum. rad. with electric fan,no more problems.It was a 350, changed to 400 with mods.

[dkn1997]

I have a be cool direct fit rad with 22" of core space, so that's what I have to work with

rad is actually 26 inches wide, but the last 4 inches are the tanks on the sides.

as far as I can tell, that' s the only one listed for a be cool direct fit for all mopars.

The rad is definately big enough, as evidenced by the fact that the car currently has no cooling problems at all, I just would rather run an electric than the flex fan/shroud I currently have. Even in the past, when I did have cooling problems, it was always at idle, could not move enough air to cool it.

If I knew then what I know now, I still would have gone for a bigger radiator like chargerdan has. would have saved me some bucks. (forgive me, I was not a member of moparchat then)

I do like the spal fans, and thanks for the links, dan- good stuff there. I have real clearance issued between rad and waterpump, so I think I will try some duals.

since I have this lousy 22" to work with, what are the biggest duals I can fit. I see spal offers many different sizes. would two 11" jobs fit, or do they actually take up more room than that? or would I be better off mounting them diagonally?

keep the replies coming!!!

[dkn1997]

almost forgot. dan, how much was that howe? I would not rule out selling my be cool on ebay for a bit of a loss and buying the one you have and getting out the sawzall, and being able to fit the two 13" fans....

would not mind the extra cooling insurance, especially if I ever do that stroker fuel injected hemi I always dream about!!!

[charger_dan]

Originally posted by dkn1997@aol.com
almost forgot. dan, how much was that howe?

My radiator is the model HRE-342EF. Ford/Mopar inlet and outlet.
Paid $199 for it 5-6 years ago.
Just checked Summit's site, and the price hasn't changed.

The only thing I don't like about the Howe is that it doesn't come, for some
reason, with a threaded bung for a drain petcock. I think
Griffin universals are the same way. Griffin universals also utilize some
plastic in their tank construction.

[coupe32]

I am running a 340 in a streetrod and had a lot of trouble overheating. I tried several electric fans but kept overheating. I was at the Walker radiator booth at the street rod nationals and was discussing the problem with one of their techs. He suggested I put a electric fan with shroud on it made by cooling components. I put one of these units on the radiator and it was the best money I have spent on the car. Before I just drove around with my eyes glued to the temp gauge and now I do not worry anymore. It cured all of my overheating problems. The fan is rated at 2700 cfm and with the built in shroud it works great.

[dkn1997]

Hey dan, I noticed a couple of things from your pic:

#1. what the hell is that old school, low output, stock alt doing on your charger!!!!!! lol, I assume that this an older pic....

#2. was the battery re-location necessary for that howe rad to fit? I know for my small be cool, I did have to notch my tray, looks like your rad really gets into that battery area.

[charger_dan]

Originally posted by dkn1997@aol.com
Hey dan, I noticed a couple of things from your pic:

#1. what the hell is that old school, low output, stock alt doing on your charger!!!!!! lol, I assume that this an older pic....

#2. was the battery re-location necessary for that howe rad to fit? I know for my small be cool, I did have to notch my tray, looks like your rad really gets into that battery area.

Heheh … sharp eye! Yep, this pic was pre-Denso alternator conversion.

On the battery tray clearance:
My battery was already relocated to the trunk before I installed the Howe
radiator. As far as clearance goes, I honestly can't say how the driver's side
radiator tank would fit/relate to the battery tray. It's been a long time since
I've had a battery and tray mounted up there.

It seems like you would probably have some options in this area if things
fit a little too snug (relocate battery to trunk $$, alter shape of existing
tray and mounting point, etc.

[deadhorse66]

I really like your cooling system, dan. Dare I ask how much you paid for the fans?

[charger_dan]

Originally posted by deadhorse66
I really like your cooling system, dan.
Dare I ask how much you paid for the fans?

deadhorse,
the fans cost me $150 each from Racer Parts Wholesale.
I just checked their website; they still cost the same.
I've been really happy with their performance and reliability.

I highly recommend running these or any other fans with
a good thermostatic switch, like the one Painless offers.
It's nice to go cruising/racing and not have to worry about
watching your temp gauge … you know the fans will activate
at 185° and turn off at 170°. Ni

[dkn1997]

hey dan, I did some looking and found a site that has the 13" spal fans for 125$

http://www.jaycorptech.com/

while I would love to duplicate you system, dan, I do have a lot of money into my radiator.... I had a proform POS rated at 2100 cfm and it would not cool at idle. I was wondering if the dual 11" spal jobs would cool me. they would probably fit, and move 2700 cfm.
I was thinking that since my proform probably did not move close to the 2100 it was advertised for, and the spal would do what they say, I might be ok

Is that enough? or should I sell my current setup and go for the 31" rad and 13" fans....

[charger_dan]

Hey Kevin, that's a good deal on those fans. $25 off is nothing to sneeze at.

As far as your idea of going with the dual 11" Spals with integral shroud,
I think they'd look and fit awesome but, in my opinion, their combined
2,780 CFM rating falls short of the 3,400-3,500 CFM minimum I mentioned
in an earlier post.

By the way, I got that 3,400-3,500 CFM number from a tech guy at SPAL-USA,
and it is a pretty good guideline, in my opinion. My fans generate a combined
3,420 CFM, and I'd even take a little more CFM if I could get it.

Basically, I've got the largest aluminum radiator I can fit in my engine bay,
and the largest fans that will fit. I'm very happy with the performance of the
system. About the only upgrades I could make would be fabbing up an
aluminum shroud, and running the trick Evans synthetic coolant instead of
distilled water. But, like I've said, this thing behaves itself in pretty hot
weather! The stock Charger engine compartment is, unfortunately, VERY
efficient at holding in engine/header heat!

How much $$$ do you have invested in your current radiator?

[dkn1997]

rad was 550, I already have a flowkooler waterpump. I could probably get 250 for the rad on ebay, maybe a bit more, so I would be on the hook for about 200 bucks to update to what you have.

I did look at the vintage air site, that fan would fit my rad, and they claim 3700 cfm, but I did not see a price....what do you think that thing costs? the thickness is 5.1", It won't fit unless I could move it off center a bit....It would be much easier to use what I have, and the rad does cool the motor at idle currently, but I have to use an engine driven fan to do it, so it can do the job, provided I move enough air through it.

plus, I would love to utilize my fancy new denso alt to it's potential, I just finished wiring up those fusible junction blocks I told you about and I fabbed a bracket for some snap-together relays, check the pic

[BThompson]

1972 Demon 440. Fans are from an Eagle Priemer. Radiator 6 year old Griffin, Ford configuration. I can let the engine temp rise to 200 in traffic and turn fans on and pull the temp down to thermostat temp(180) in 3 minutes in 85 degree weather. Fans cost me 20 dollars at boneyard.

[charger_dan]

Kevin,
Your junction block and relay bank looks good. Clean routing and
mounting. Nice work.

The Vintage Air Monster Fan would certainly provide enough airflow for
a hot big block Mopar. Web site says it'll cool 950 horses. I'll bet that thing
sounds like a B-29 prop when it winds up!

As far as cost, looks like you'd need to call them. I had a price sheet and
printed catalog, but it's all in storage now. I would think you could buy
it now, and see about mounting it slightly off-center, to avoid any inter-
ference with your pulleys. You're the crafty type, so you could just buy the
fan and fab your own custom shroud from sheet aluminum. If your current
radiator cools effectively at freeway speed, then this fan should do fine for
you at idle. 3,700 CFM is an awful lot of air.

Some may think this fan overkill, but I still say go with as much CFM as you
can suck through your radiator. Call me crazy, but I'm very conservative
when it comes to designing the vitally-important systems on my car.

PS: you'll probably want to consider a conversion to remote voltage sensing
for your regulator if you go with electric fans. It's a real good idea.

[gsmopar]

I've herd of a lot of guys using factory electric fans. I'm going to the bone yard this week to look for a Ford Aerostar or Lincoln Mark VIII. I work with the guy in the link listed below. I've seen him drive that 11 second chevy to work in the Arizona Summer (120 F). All he's using is the Lincoln Fan.

Lonnie's Hot Rods


Later,

Greg

[dkn1997]

Call me crazy

Dan.....Your'e crazy.

But seriousely, what is remote voltage sensing??? and why would the use of this monster fan mean that I need it?

[HankL]

Back to the original question - how can you measure the cfm going thru the radiator ?

If you know anyone who works in coal mining or quarrying underground, you need to ask them if you can borrow an 'anenometer' from their shift foreman or engineering crew.

This is a small brass instrument that has a propellor driving a watch dial marked in feet. These devices are used to measure the air blowing thru tunnels. All shift foreman in underground mines must have one and know how to use it.

It would be easy to measure the cfm on the radiator with an anenometer, take less than half an hour to do.

You can also use these to measure exhaust output or intake flow.

Under federal law, the anenometers have to be calibrated every 3 years at a Mining Safety and Health Administration (MSHA) certified lab and are accurate to at least 2%

[charger_dan]

Originally posted by dkn1997@aol.com
What is remote voltage sensing???

Here is a good explanation of remote voltage sensing:
http://www.madelectrical.com/electri...esensing.shtml

Why would the use of this monster fan mean that I need it?

With the addition of more and more electrical accessories (fuel pumps, fans,
line locks, etc.), you want proper voltage (13.8-14.4V) maintained at the
junction that's powering up all these accessories.

In OEM configuration, your regulator is monitoring system voltage (via the
IGN wire on your reg. plug) from your dash/ignition switch area. Thus, the
regulator tells the alternator when to charge based on the voltage require-
ments at the dash.

If you modify your regulator's IGN wiring path so that the regulator monitors
voltage from the main load "buss" (the point where all your elec. accessories
are pulling from), then the regulator will instruct the alternator to maintain
proper voltage at that crucial point where the most load is being encountered.
As an example, my main load buss is the large starter relay stud, and it's the point
where I'd relocate my reg's voltage sensing wire to.

So in other words, you're rearranging a couple of wires to allow the regulator
to monitor voltage and maintain 14.4V at the high-load point in your car's
wiring. This ensures your accessories receive the proper amount of voltage
for efficient operation.

To make this mod on a Mopar, all it requires is purchasing a simple relay,
like the ones you're using.

[dkn1997]

so, would I use my existing ign wire on the reg to trigger a relay, and that relay would provide power to the reg? that relay getting power from the same junction as all my high draw stuff like fans, etc...?

essentially substituting a wire from my distribution block (that actually supplies direct bat voltage to my fan,fuelpump, etc) for the existing ign wire on the reg????

also, since my starter relay is where alt wire and wire that powers up my new distribution block meet, which place would I use to power up the reg, the stud on the starter relay, or another wire coming out of the distribution block?

[charger_dan]

Kevin, take a gander at the attached schematic.
The relay is activated by the ignition key "run" wire.
When activated, the relay allows the regulator to monitor
system voltage (via red wire in this drawing) from the point
where the most current is being consumed.

You'd want your regulator to monitor voltage at the junction
where you're supplying power to the greatest number of accessories.
In your particular case, it sounds like the distribution block would be
the likely location for the regulator's sensing wire (since that's where
your relay bank is drawing current from, right?)

[dkn1997]

sounds easy enough, and I already have two relays I am not using on that bracket.

just got my distributor back from don today. will try to get it in the next couple of days and see how she runs....

[charger_dan]

Let me know how the re-wire works.
I recently helped my bro do this same mod, along with rewiring his headlights
through a relay, and he's pretty happy with the results.
Good luck