next power mod

[tm america]

does anyone know the diameter or the fan on a deuce .i'm looking to free up as much hp as i can now since i think i have turned the fuel up as much as i can safely.so i'm gonna put a flex fan on there should be able to free up 20hp with that .and the new alt is alot less rotating weight to maybe i'll do something with the flywheel to when i have the trans out this week doing the rear seal on the engine

 

[mudguppy]

... so i'm gonna put a flex fan on there should be able to free up 20hp with that ....

how'd you come up w/ that figure?

 

[drgreg]

20hp, is your fan 5ft diameter?

 

[Numbers]

The partial engagement or parasitic drag of a viscous drive can contribute to engine overcooling, resulting in unnecessary fuel consumption. For example, with a truck engine speed of 1400 rpm, an average vehicle speed of 50 mph and yearly travel distance of 30,000 miles, a viscous drive consuming 0.5 hp (0.4 kW) in the off mode burns approximately 48 gal. of fuel per year.

A comparison of viscous drives and on/off fan drives for diesel engine cooling | Diesel Progress North American Edition | Find Articles at BNET

The entire article is about 4 pages long. Yes, there is a HP advantage but the real advantage lies with an electric fans capability to save fuel. Please correct me if I am wrong on this reading.

 

[Numbers]

One table which I have adjusted for approximate (but not everyones) rate of Diesel

Table 2. - A comparison of fan drive system fuel consumption,
at a cost of $1.25 per gal., according to an SAE-DOT test.

Fan Drive System Fan HP Fuel Consumption Cost of Fuel
(gal/10,000 miles) for Fan Drive

Direct Drive 20 225.71 $282.14
Viscous Drive 21 68.46 $85.57
On/off Drive 20 11.29 $14.11

$564.28 at $2.50 a gallon (Direct Drive)
$171.15 at $2.50 a gallon (Viscous Drive)
$28.23 at $2.50 a gallon (On/off Drive)
I think one can safely say that an electric fan is capable of saving some serious coinage at the pump. If I am not mistaken the above figures are for a vehicle that makes considerably more MPG than your standard Deuce.

 

[crazyplowboy]

does anyone know the diameter or the fan on a deuce

20 inches

 

[Westech]

There was a figure of 15 hp the fan takes to run at WOT. The fan broke off on my deuce during a road trip (yeah like fin by fin) I ran the truck for a month or two with no fan at all. Could not really tell a difference.

 

[zb39]

You could probaly save some hp by going to smaller fan but 20 seems like a lot..

 

[tm america]

i'm thinking a flex fan not only will it be lighter but wont take as much hp to push all that air .i'm gonna keep the same size fan .plus flez fans dont get sucked into the rad in water like solid blade fans have a tendincy to do.on alot to the newer cars and truck if the fan clutch locks up it will make the car feel like the cat is clogged .it will take so much power that that trans wont even shift right .and that is just with a 12-16 inch fan when you are working with 140-200hp even a 10hp increase is a big gain.5 hp here 10 hp there 2 there it all adds up

 

[tm america]

in that article it says 16hp to as much as 41 hp to drive the fan and they did the economy ratings based off of 20hp -21hp which is about what i was figuring based off the fan size and weight

 

[tm america]

20hp would be a 14% increase in hp .that would be a big help in the hills and with a heavy load .it would have made all the difference on my last trip

 

[Numbers]

20hp would be a 14% increase in hp .that would be a big help in the hills and with a heavy load .it would have made all the difference on my last trip

Have you made a choice on which one to go with? Lots of choices out there but the CFM rates vary, the temp switch setup varies, and of course size variances.

 

[atankersdad]

According to the logic in this post, if I Bob my truck I will pick up 200+ HP due to dropping 1400 lbs. I am confused...

 

[shootiniron]

Huh!

 

[Avn-Tech]

TM America,

Instead of changing the diameter of the fan, go electric and free up more HP.
Also if you kill the feild power in the Alternator, you would free HP as needed.
The batteries could run the fan/lights ect for a while (like climbing a hill).

Latrrrrr
Avn-Tech

 

[tm america]

you would free up power by loosing the weight dont think it takes the much power to turn the rear end since it is geared.and there is a difference between net and gross hp my truck makes about 200hp gross but has probably 150net cuz of the power lose of the fan,alt,and air compressor.hp is like money its not about how much you make it,s about how much you keep less power lose=going faster and getting better mpg.it's like the difference between an engine dyno and a chassis dyno all that matters is what you put to the tires!

 

[tm america]

i got my fan today i didnt change the diameter just the type of fan.i got a flex fan.the difference is the blades straighten out as the rpms come up thus taking less power to turn the idea is that as you start going the air is being pushed through the rad cuz the truck is moving.with the stock deuce fan the blades are fixed and the more you rev it the more power it takes to turn the fan.so the more power you make the more it takes to run the fani'm not doing anything that hasnt been done before just look at any drag car weather you make more power or just free up what you have it has the same effect and ldt's are hard to safely get alot of power from but easy to free up power so i'm doing both

 

[mudguppy]

... i'm not doing anything that hasnt been done before just look at any drag car weather you make more power or just free up what you have it has the same effect ...

point being this - flex-a-lite fans have been around for years, but as you said, they were designed for gassers. i'm skeptical that the blades are going to be freeing up that much hp at 2500 rpm - these fans were made to free up hp on cars turning much higher rpms than that... more like 4 - 5k.

i think you should do some drag testing. i'm serious. do at least 3 if not 5 runs from stand still to a specific point and get a baseline average time. then take the fan off completely and retest another series. then put the flex fan on and retest for a final series.

i'd be interested to see, not only the difference in stock vs AWOL, but stock vs flex fan. you could probably do all this in less than an hour?

 

[jwaller]

the only way to test for HP increases in our trucks is to use the same piece of road and stay in the same gear. the way I used to do it with my deuce is to cruise at 45mph in 5th gear and accelerate up to 55.

this way you take shifting out of the equation.

 

[tm america]

gas or deisel doesnt matter it's more about fan speed.the ratio of the pulleys are different between gas and deisel engines fan speed of a deisel at 2500 is pretty close to the fan speed of a gas engine at 4500.it wont be a perfect set up i do need the blades to stay bent a little later in the rpm range than you would want on a race car since i dont want to have overheating problems.i'm guessing the blades will flatten out around 1800-2000rpm.but we will see when i put it on this weekend