Home » Public Forums » GMCnet » Electric Cooling fan revisited
| Electric Cooling fan revisited [message #84095] |
Tue, 11 May 2010 14:39  |
hertfordnc
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Registered: September 2009
Location: East NC
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I searched the archives here and at other sites and looked over past discussions on this topic. Not sure i did an exhaustive search as the search function seems a little buggy but here goes.
Here's the general consensus-
- it won't do any good the energy is the same no matter where it comes from and the only reason the car makers use them is to accomidate tranverse mounted engines.
- no electric fan can move enough air to do the job.
- I tried it and it did not work therefore it's a proven non-starter
Here's what I found and what i'd like to see discussed:
- The car makers are putting electric fans in bigger rear wheel drive vehicles. I think they prefer the clutch fan for its simplicity but have to use electric in some applications to get mandated fuel economy.
- Apprently, the fans that come on some taurus's and other big Fords move 5500 CFM.
see here:
http://www.modmyf150.com/2010/02/15/ford-f150-electric-radiator-cooling-fan
- This is a fairly popular mod among the offroad guys. They put the Taurus fan on big block modified Jeeps because they are working them hard but with not much airflow across the grille.
So, let's rip this up one more time. If someone can't point out the flaw in my logic I will look for a big ford fan next time i'm in the pick and pull and try it myself.
thanks
Dave & Ellen Silva
Hertford, NC
76 Birchaven, 1-ton and other stuff
Currently planning the Great american Road Trip Summer 2021
It's gonna take a lot of Adderall to get this thing right.
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| Re: Electric Cooling fan revisited [message #84143 is a reply to message #84095] |
Tue, 11 May 2010 21:16  |
JohnL455
Messages: 4447
Registered: October 2006
Location: Woodstock, IL
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A Taurus is a 3.x liter engine in a passenger car. That fan was sized for just to do that job. No way it's big enough alone for the 455 in a vehicle weighing 3x as much. They say that the clutch fan can "waste as much as 15 horsepower" and for good reason. That's what it take to move that much air. Do you know how large and heavy a 12V 15 HP electric motor would have to be??? And the alternator can't support 15HP continuous.
John Lebetski
Woodstock, IL
77 Eleganza II
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| Re: Electric Cooling fan revisited [message #84171 is a reply to message #84143] |
Wed, 12 May 2010 06:37 |
hertfordnc
Messages: 1164
Registered: September 2009
Location: East NC
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The potential 15hp power loss and the fact that the proposed fan comes from a 3.0 liter engine are not part of the argument.
The question is, how much air do we need to move? If it's somewhere around 6000 CFM then these people might be on to something.
If you look around the other forums where people are doing this mod you'll find a third party 5500 CFM fan but it costs $500.
So the jeep guys run off the to the junkyard for the Taurus fan. Not the Windstar and not the Probe, Just the Taurus (and maybe some lincolns)
Apparently, when Ford engineered in all the requirements for performance, MPG and front seat leg room they were left with an engine that ran hot. It has very little to do with the size of the motor. The Windstar uses the same 3.8 V6 but has a smaller fan. I guess because it has more grille.
Ford solved the engineering problem on the Taurus with a really big fan.
I don't know if the 15hp loss is true. If it were it would take 930 amps to make up for it electrically.
If there is no real gain then why did Chevy put electric fans on the 5.3 liter Silverado?
Check out these links or google 'taurus, electric fan, jeep.'
http://www.pirate4x4.com/tech/taurus/
http://www.virtualjeepclub.com/showthread.php?t=6771
http://www.jeep-xj.info/HowtoTaurusFanInstall1.htm
Dave & Ellen Silva
Hertford, NC
76 Birchaven, 1-ton and other stuff
Currently planning the Great american Road Trip Summer 2021
It's gonna take a lot of Adderall to get this thing right.
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| Re: Electric Cooling fan revisited [message #84189 is a reply to message #84095] |
Wed, 12 May 2010 09:47 |
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Tom Lins
Messages: 372
Registered: February 2004
Location: St Augustine, FL
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| hertfordnc wrote on Tue, 11 May 2010 15:39 |
So, let's rip this up one more time. If someone can't point out the flaw in my logic I will look for a big ford fan next time I'm in the pick and pull and try it myself.
thanks
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To make it a reproducible experiment you should probably either have your radiator professionally refurbished or get one of the aluminum radiators. If you don't you really do not know how well you are transferring the heat away from the engine, and weather the electric fan can do the job.
JMHO
My SOB has a hydraulically powered side radiator fan in a 30k pound vehicle so it might be possible to do what you want, but to be honest I doubt the engineers that designed my SOB were worrying about how much power it took to drive the fan. There might not be any "HP savings" involved.
Tom Lins
St Augustine, FL
77 GM Rear Twin, Dry Bath, 455, Aluminum Radiator Quad-Bag Suspension Solar Panel
Manuals on DVD
YOUTUBE Channel: GMC Dealer Training Tapes
http://www.bdub.net/tomlins/
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| Re: Electric Cooling fan revisited [message #84191 is a reply to message #84189] |
Wed, 12 May 2010 09:58 |
Keith V
Messages: 2337
Registered: March 2008
Location: Mounds View,MN
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Remember that the fan only needs to perform at low speeds.
Once the vehicle is moving the fan is just slowing down the airflow.
So if you are climbing a big hill really slow you're screwed...
Keith Vasilakes
Mounds View. MN
75 ex Royale GMC
ask me about MicroLevel
Cell, 763-732-3419
My427v8@hotmail.com
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| Re: Electric Cooling fan revisited- MORE DATA [message #84333 is a reply to message #84191] |
Thu, 13 May 2010 06:56 |
hertfordnc
Messages: 1164
Registered: September 2009
Location: East NC
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According to these people:
http://www.flex-a-lite.com/auto/html/monster-electric.html
Their 5500 CFM fan uses 28 amps.
That comes out to .4 HP (28 X 12 / 750)
So what about this 15hp parisitic drag? Is that a real number? or theoretical hype from peopel trying to sell elctric fans?
And some simple math occurred to me; 5500 CFM is roughly equal to a one sq. foot opening at 60MPG, Right? Any flaws in my math?
Next question, and maybe one of the aviators can answer it;
How much air are we getting into out radiators?
My Radiator is nearly six sq feet but it is obstructed and broken up by the grille and bumper. What happens to that air volume? Is it lost to dissipation or still applied to the radiator at higher speed?
Dave & Ellen Silva
Hertford, NC
76 Birchaven, 1-ton and other stuff
Currently planning the Great american Road Trip Summer 2021
It's gonna take a lot of Adderall to get this thing right.
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| Re: Electric Cooling fan revisited- MORE DATA [message #84344 is a reply to message #84341] |
Thu, 13 May 2010 08:49 |
fred v
Messages: 999
Registered: April 2006
Location: pensacola, fl.
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| Tom Lins wrote on Thu, 13 May 2010 08:39 |
Two 15 inch fans is 4.9 square feet
You probably need to calulate the worst case scenerio. Twenty five miles an hour up a 6% grade for 20 miles. That would be route 14 from Shell, Wy to the pass at the top of the Bighorn mountians. Don't forget the rise in altitude from 4200 feet to 8000
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or just don't go there!
Fred V
'77 Royale RB 455
P'cola, Fl
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| Re: [GMCnet] Electric Cooling fan revisited- MORE DATA [message #84349 is a reply to message #84344] |
Thu, 13 May 2010 08:53 |
Steven Ferguson
Messages: 3447
Registered: May 2006
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Fred,
I presume you mean route 14A. I made that mistake once, on a
motorcycle. Saw one car (had a priest in it) and one deer on the
entire trip. Some of those switchbacks required low gear on our Gold
Wing. When we got to the top, we were treated to a 40mph blizzard.
What a ride! But you're right, I don't think I want to do it again.
On Thu, May 13, 2010 at 6:49 AM, fred veenschoten <fredntoni@cox.net> wrote:
>
>
> Tom Lins wrote on Thu, 13 May 2010 08:39
>> hertfordnc wrote on Thu, 13 May 2010 07:56
>> > According to these people:
>> >
>> > http://www.flex-a-lite.com/auto/html/monster-electric.html
>> > And some simple math occurred to me; 5500 CFM is roughly equal to a one sq. foot opening at 60MPG, Right? Any flaws in my math?
>>
>>
>> Two 15 inch fans is 4.9 square feet
>>
>> You probably need to calulate the worst case scenerio. Twenty five miles an hour up a 6% grade for 20 miles. That would be route 14 from Shell, Wy to the pass at the top of the Bighorn mountians. Don't forget the rise in altitude from 4200 feet to 8000
>
> or just don't go there!
>
> --
> Fred V
> '77 Royale RB 455
> P'cola, Fl
> _______________________________________________
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Steve Ferguson
'76 EII
Sierra Vista, AZ
Urethane bushing source
www.bdub.net/ferguson/
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| Re: Electric Cooling fan revisited- MORE DATA [message #84355 is a reply to message #84341] |
Thu, 13 May 2010 09:11 |
hertfordnc
Messages: 1164
Registered: September 2009
Location: East NC
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| Quote: |
Two 15 inch fans is 4.9 square feet
You probably need to calulate the worst case scenerio. Twenty five miles an hour up a 6% grade for 20 miles. That would be route 14 from Shell, Wy to the pass at the top of the Bighorn mountians. Don't forget the rise in altitude from 4200 feet to 8000
|
That's not what i meant- I was comparing CFM to real world moving down the road.
If a fan CAN move 5500 CFM that is the same air flow as a 1 sq. foot opening moving down the road at 60 MPH. (5280 FEET per mile- 5280 cubic feet passing 1 sq foot in 60 sec)
Can anyone tell me the CFM of the clutch fan at, say, 3000 RPM?
Dave & Ellen Silva
Hertford, NC
76 Birchaven, 1-ton and other stuff
Currently planning the Great american Road Trip Summer 2021
It's gonna take a lot of Adderall to get this thing right.
[Updated on: Thu, 13 May 2010 09:13] Report message to a moderator |
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| Re: [GMCnet] Electric Cooling fan revisited- MORE DATA [message #84359 is a reply to message #84333] |
Thu, 13 May 2010 09:17 |
Terry Skinner
Messages: 379
Registered: January 2004
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Over the past 15 years I have seen this subject brought up and I have
seen all the same "hypothetical/theoretical" answers. If you are
really interested than DO IT!! Keep us posted as to how it goes. Some
will tell you that you are wrong (no mater what the results) and some
will pat you on the back. Last year I had the opportunity to do this
same experiment. Fan clutch not working, 100 degrees, and towing a
4000 lb van on the back. Purchased an electric fan. Mounted it in
front of the radiator and direct wired it to the battery. Every time I
stopped I had to unhook the wires from the battery. 350 miles later I
delivered the GMC to its owner. Not a problem. No over heating. Maybe
I had an exceptionally good radiator. Maybe a headwind. All kinds of
things could come into the equation. Things I could not test with what
I had available. Bottom line is it worked for me. Would I do it
again?? You bet!! In fact I did purchase another fan when I brought a
26' back from Utah just to carry along. Never had an opportunity to
test it again but I was ready...........Terry
PS I have had more trouble with fan clutches.
On Thu, May 13, 2010 at 4:56 AM, dave silva <gmc@davesilva.com> wrote:
>
>
> According to these people:
>
> http://www.flex-a-lite.com/auto/html/monster-electric.html
>
> Their 5500 CFM fan uses 28 amps.
>
> That comes out to .4 HP (28 X 12 / 750)
>
> So what about this 15hp parisitic drag? Is that a real number? or theoretical hype from peopel trying to sell elctric fans?
>
> And some simple math occurred to me; 5500 CFM is roughly equal to a one sq. foot opening at 60MPG, Right? Any flaws in my math?
>
> Next question, and maybe one of the aviators can answer it;
>
> How much air are we getting into out radiators?
>
>
> My Radiator is nearly six sq feet but it is obstructed and broken up by the grille and bumper. What happens to that air volume? Is it lost to dissipation or still applied to the radiator at higher speed?
>
>
>
>
> --
> Free to good home- the rest of a 1974 GMC. good for extension, or trailer. But you gotta' take the whole thing -zip 27944- rear wheels, glass, etc.
> _______________________________________________
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> List Information and Subscription Options:
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--
Terry Skinner
253-686-2624
Roy. Washington
'76 GMC
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| Re: [GMCnet] Electric Cooling fan revisited- MORE DATA [message #84370 is a reply to message #84349] |
Thu, 13 May 2010 09:48 |
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Tom Lins
Messages: 372
Registered: February 2004
Location: St Augustine, FL
Karma: 1
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| Steven Ferguson wrote on Thu, 13 May 2010 09:53 |
Fred,
I presume you mean route 14A. I made that mistake once, on a
motorcycle. Saw one car (had a priest in it) and one deer on the
entire trip. Some of those switchbacks required low gear on our Gold
Wing. When we got to the top, we were treated to a 40mph blizzard.
What a ride! But you're right, I don't think I want to do it again.
|
Nah, 14a is the one with 9-10% grades at times, we did not go on that one last year. We went west on 16 thru Ten Sleep going to Yellowstone and coming back east we took 14 thru Graybull and Shell. And it was in the SOB which is more suited to the mountians than our GMC is.
Tom Lins
St Augustine, FL
77 GM Rear Twin, Dry Bath, 455, Aluminum Radiator Quad-Bag Suspension Solar Panel
Manuals on DVD
YOUTUBE Channel: GMC Dealer Training Tapes
http://www.bdub.net/tomlins/
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| Re: Electric Cooling fan revisited- MORE DATA [message #84378 is a reply to message #84373] |
Thu, 13 May 2010 10:25 |
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Tom Lins
Messages: 372
Registered: February 2004
Location: St Augustine, FL
Karma: 1
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| Tom Lins wrote on Thu, 13 May 2010 10:56 |
| hertfordnc wrote on Thu, 13 May 2010 10:11 |
| Quote: |
Two 15 inch fans is 4.9 square feet
You probably need to calculate the worst case scenario. Twenty five miles an hour up a 6% grade for 20 miles. That would be route 14 from Shell, Wy to the pass at the top of the Bighorn mountains. Don't forget the rise in altitude from 4200 feet to 8000
|
That's not what i meant- I was comparing CFM to real world moving down the road.
If a fan CAN move 5500 CFM that is the same air flow as a 1 sq. foot opening moving down the road at 60 MPH. (5280 FEET per mile- 5280 cubic feet passing 1 sq foot in 60 sec)
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The problem I see it as is that the fan is 4.9 Square feet and moves 5500 cubic feet of air thru that 4.9 square feet which is equal to about 12 MPH not 60 MPH
JMHO
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I am going to reply to myself because I don't like the way my reply sounds. Too snippy.
I don't have the formulas to really calculate this out to actually get an answer. There are just too many variables and formulas that I do not have.
I am certain it can be done since my SOB has a hydraulic fan, However I doubt it will save any power. Every Time you convert power from one form to another you lose some in the conversion process.
Tom Lins
St Augustine, FL
77 GM Rear Twin, Dry Bath, 455, Aluminum Radiator Quad-Bag Suspension Solar Panel
Manuals on DVD
YOUTUBE Channel: GMC Dealer Training Tapes
http://www.bdub.net/tomlins/
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| Re: Electric Cooling fan revisited- MORE DATA [message #84379 is a reply to message #84373] |
Thu, 13 May 2010 10:30 |
hertfordnc
Messages: 1164
Registered: September 2009
Location: East NC
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[quote title=Tom Lins wrote on Thu, 13 May 2010 09:56 The problem I see it as is that the fan is 4.9 Square feet and moves 5500 cubic feet of air thru that 4.9 square feet which is equal to about 12 MPH not 60 MPH
JMHO[/quote]
That was just get a frame of reference- what does 5500 CFM look like? it looks like one fifth the air that would flow across your radiator at 60 mpH if you had no obstructions.
The unkowns are;
1. What is the CFM of the clutch fan for comparison
2. What is the volume of air carrying away heat at cruising speed. (aqfter it's broken up by the grille)
If we had good answers to those two questions it would be fairly easy to calculate what would work.
Dave & Ellen Silva
Hertford, NC
76 Birchaven, 1-ton and other stuff
Currently planning the Great american Road Trip Summer 2021
It's gonna take a lot of Adderall to get this thing right.
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| Re: [GMCnet] Electric Cooling fan revisited- MORE DATA [message #84405 is a reply to message #84378] |
Thu, 13 May 2010 13:04 |
Steven Ferguson
Messages: 3447
Registered: May 2006
Karma: 0
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Senior Member |
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Tom,
You are probably correct but what I'm striving for is control. The
fan clutches don't have that. The new ones seem like they're coming
on far too often and at ambient shroud air temps that don't make
sense.
On Thu, May 13, 2010 at 8:25 AM, Tom Lins <tlins@optonline.net> wrote:
>
>
> Tom Lins wrote on Thu, 13 May 2010 10:56
>> hertfordnc wrote on Thu, 13 May 2010 10:11
>> > Quote:
>> > > Two 15 inch fans is 4.9 square feet
>> > >
>> > > You probably need to calculate the worst case scenario. Twenty five miles an hour up a 6% grade for 20 miles. That would be route 14 from Shell, Wy to the pass at the top of the Bighorn mountains. Don't forget the rise in altitude from 4200 feet to 8000
>> >
>> >
>> > That's not what i meant- I was comparing CFM to real world moving down the road.
>> >
>> > If a fan CAN move 5500 CFM that is the same air flow as a 1 sq. foot opening moving down the road at 60 MPH. (5280 FEET per mile- 5280 cubic feet passing 1 sq foot in 60 sec)
>>
>>
>> The problem I see it as is that the fan is 4.9 Square feet and moves 5500 cubic feet of air thru that 4.9 square feet which is equal to about 12 MPH not 60 MPH
>>
>> JMHO
>
>
> I am going to reply to myself because I don't like the way my reply sounds. Too snippy.
> I don't have the formulas to really calculate this out to actually get an answer. There are just too many variables and formulas that I do not have.
>
> I am certain it can be done since my SOB has a hydraulic fan, However I doubt it will save any power. Every Time you convert power from one form to another you lose some in the conversion process.
>
>
> --
> Tom Lins
> Milltown, NJ
> 78 xPB
> GMC Dealer Training Tapes on CD
> GMC Maintenance Manuals on CD
> www.bdub.net/tomlins/
>
> http://www.escapees.com
>
> _______________________________________________
> GMCnet mailing list
> List Information and Subscription Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
--
Steve Ferguson
'76 EII
Sierra Vista, AZ
Urethane bushing source
www.bdub.net/ferguson/
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