yea remember me and ryan were trying to find out what the stock fan CFM was... we never did figure it out..regardless... 2 reasons tell me that the elec fan was WELL worth it... number 1 ... BUTT DYNO... really helpd out big time... and number two... i read two reports/articles.. one being a mustang and another being a truck.. cant remmeber what kind... and both gained HP enough to even over come the small amount of stress that is put on the alt...if any... the only way to actually dyno a yes or no answer is to run w/ mechanical fan.. run with elec fans of the alt and run with no fans at all.. and i havnt seen a test like that to come up with a good constant or base line to work off of.

the funny thing that i dont realize about this "strain on the alt" .. there isnt any real strain on it... mechanically speaking that is... the alt may strain to work harder.. but i cant imagine anything internally that would make an alt mechanically create extra drag on the belt system... i mean the alt doesnt move any substance besides "current" like the water pump ac pump PS pump.. these all move liquids which create the resistance to their respective pumps intern creating resistance on the belt system. the alt just spins... the alt may work harder..but the motor really doesnt... not enough to worry about the mpg/hp...

oh yea... i gained 2mpgs from the conversion... along with like 6 other fellas at ps.com that have done the conversion also agree that there mpg's and hp's have gone up...

with the 180 tstat. a properly working and clean cooling system and my fans..i do not see any cooling problems what so ever... knock on wood ofcourse...summer is still a ways a way.

 

yeah i agree it probably is better on the whole, but looking at it from my point, the alt runs off the block belt, stupid set up but it's what we got, and thus if the alt needs to draw more power it will make the engine run at higher rpm's.

just saying that my engine on start up will run at higher rpm's to compensate for the draw from my stereo to bring up the volts comin out of the battery.

any less rotating mass off the engine will free up horsepower, no matter how much it is. i read somewhere or heard on the radio that the air conditioning takes up 8 hp to run. hmm that would be the next thing after the fan to go, but hate those hot days with out it.

yeah i think the reason i was doing all those calculations (which got stalled because i need the air speed to do the math) was for you shott.

i'll keep working on it and call some kite shops this summer and see what we can figure out. hell i might just go to an electric fan too to figure it out. gotta love being an engineer.

 

For those who are looking for Direct Bolt Flex a Lite fans, here it is : http://www.peytonperformance.com/ite...n--FAL285.html . It's part 290, 285 will work but you dont have the relays and what not included (it says on website). It's a dual 15 inch setup, but i dont know what kind of amp it draws. Little pricey too and i think that the estimated gains in HP are overrated (15 hp from a fan at the wheels? gimme a break).

Hope this helps

EDIT:

Ok i found the site with the specs on it, click the specs link.

Mounting Surface Required- 17" x 31 7/8" x 4 1/2"
Fan Diameter- Dual 15"
Fan RPM @13.5VDC- 1000-1900 Variable
Number of Blades/Fan Blade Angle- 8/26°
Airflow-Cu. Ft./Min. at 0º Static Pressure- 3300-5500
Amp Draw- 12-28
Mounting System- Universal Brackets
Adj. Thermostat 180º-240º
Air Conditioning Relay
Var. Speed Control 60-100%


12-28 amps?!?! Yeah buddy, thats what i'm talking about =)

 

When figuring on an electric fan conversion,
look at a pay back time based on about a 4% gain in MPG
which generally means to keep the costs down with a salvage yard fan.

The Lincoln Mark VIII fans have what appears to be the highest capacity:

http://www.geocities.com/smithmonte/...rkVIII_Fan.htm

An Audi A4 electric fan has been reported as having a shroud size that nearly fits Rams.

Keep in mind that most of the Ram alternators are either 90 amps or 136 amps.
Typical running amps are in the 29-60 amp range already.

Me personally, I have been thinking about mounting a small electric fan on a piece of strong foam board and mounting it inside the stock Ram radiator shroud just in front of the factory viscous clutch fan.

I believe this way I could take off the viscous fan for all purposes except heavy trailer towing, and when towing just re-install the viscous clutch fan without removing the electric fan in front.

I have also thought about cutting in two places the mounting flange of the stock 5 blade fan unit so that it could be re-installed in two pieces. This would avoid having to take the 36 mm clutch nut off at all.
===
old post
====
Following up on the air dam on/off MPG tests I did on Monday the 23rd,
today I did a MPG test run at a cruise-controlled 70 mph over the same stretch
of Interstate 40 without my radiator fan.

I filled up at the same gas station, set the air conditioning the same, and
the weather was nearly the same - 70-79 degrees. Today there was a 10-15 mph
wind coming from the west (more on that later).

The truck was about 4 lbs heavier because I was carrying the big 1 7/16 inch
wrench, hammer, and small 1/2 inch flare wrench I used to remove the fan
bolts.

By the Exxon gas pump I used 11.105 gallons of 87 octane.
By my (corrected) truck's odometer I went 218.5 miles.

MPG at 70 mph without the radiator fan was 19.68
Compared to 18.94 MPG on Monday's test with fan,
this represents about a 3.8% gain.

The Oztrip meter results from measuring fuel injector on-time were similar,
showing a consumption of 11.6 gallons over 218.7 miles
for a fan-less mpg of 19.34
On Monday with the fan the Oztrip had showed 18.86 mpg, or a gain of 2.5%

When I first started this test run at about 10 am, the Oztrip meter showed
surprisingly good MPG - about 20 - so I had high hopes for what fan removal
was going to do.

Unfortunately, I found that part of the gain on the southeast bound leg of the
trip was due to the 10-15 mph winds at my back.

When I turned around at Wilmington NC and headed back, the average mpg
steadily dropped as I now drove against a head wind. Looking at the Oztrip
trip computer numbers it seems I averaged 19.96 on the southeast bound drive
with the favorable tailwind, and 18.7 driving northwest with the unfavorable
headwind. This was the 1st time I had bothered to watch for what winds do to
mpg. Looks like they can raise/lower mpg by 1.6 even at a "calm" 10-15 mph
level.

As to the temperature of the coolant without the fan - it stayed very steady
at 180 degrees during the MPG test run even with the air conditioner on.

When I slowed to a stop at the end of the trip while turning back into the gas
station, the temp gauge indicated a momentary rise to about 195.

I actually took the fan off late yesterday afternoon and drove around without
it to experiment. As long as the truck kept moving the temp gauge stayed at
180. I parked the truck and let it idle for about 10 minutes. This raised
the temp gauge to about 210-220. I then put on the heater full blast to see
if this would lower the temperature back to 180. It did not - the temp stayed
the same and neither fell nor raised any more. I then drove the truck again.
Within 1 mile the temp had dropped to 200 and within another mile it was back
at 180 degrees F.

The fan on a 5.9V8 Magnum is kind of funky looking. It has 5 blades, but 2 of
them are bunched together and the other 3 are spaced out normally. There is a
stiffening wire embedded in the blades. It takes less than 15 minutes to take
this fan off, but if the fan had been made in two parts that split - you would
not have to take the big nut off the fan clutch - and the fan could be removed
in 5 minutes.

Instead of buying a 36 mm wrench {1.417 inches}, I cut two strips of metal
from a tin can. These strips turned out to be 0.010 inches thick. I taped
two such home-made 'shims' to the inside faces of my 1 7/16 wrench {1.4375}
which closed the opening up to 1.4375 - 0.020 = 1.4175 This worked fine to
loosen the clutch-to-waterpump nut. Make the shims 'fish hook' shaped and you
can tape them in place from the backside.

I may try to drive without the fan in city driving a bit to see what happens,
but I am carrying it with me just in case I have trouble.

I still have the Evan Cooling 'waterless' NPG coolant in my engine. This
won't boil over until 370 degrees so I have some safety factor that a normal
antifreeze would not have.

HankL

 

dang hank! half of these guys have to take a sick day in order to read most of your posts lol!!!!

when worrying about an alternator being powerfull enough to run fans,, is pretty much most important at idle,,since alternators only put out there rating amperage at or above approx 1300 rpms/.... im our case its 1450 - 1500.. any think lower like idle... is when youll drain straight off the batt.

 

dang hank! half of these guys have to take a sick day in order to read most of your posts lol!!!!

Shott - you are freakin killing me!! I have to agree - I've thought about saying something like this several times - but couldn't find the right words.....You hit it right on the head! Laughed my a$$ off for the first time in a while when I saw that - Thanks! [sm=icon_cheers.gif]

 

lol... reading hanks posts is like curling up with a good book on a rainy day... although taking my computer to the couch would be uncomfortable... lol!

we all appreciate hanks info... he's either WICKED SMART or really keeps good tabs on the stuff he reads on the net... i vote for both

 

I agree - he comes up with some good info that the rest of us mere mortals don't have time to find or can't find. You cracked me up though!

 

I second shotts response, damn boy, you should be working at like... I dunno....

Where do you work at? lol