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Bracewell 10-24-2010 05:42 PM

electric fan
 
Does replacing your factory motor mounted fan with an electric fan really increase your horse power? Lee

poncho62 10-24-2010 06:10 PM

It takes a certain amount of horsepower to drive a pulley run fan, so I guess there is a horsepower increase sent to the transmission.

The down side is that an electric fan puts more strain on the charging/electrical system

There are fans that draw less hp than others

wayneooo 10-24-2010 07:54 PM

i dont think so on my 01 s10 4 banger i tryed it and during the summer the engine runs very hot(210) all the time bad enuff that i blew the radiator had to put a bigger rad in and run it w/o the thermo right now in the cooler months no problem

F-BIRD'88 10-25-2010 02:26 AM

The electricity to power a electric fan is made by spinning the alternator. Takes power to do that. There is no free lunch.

99% of the electric fans do not pull enough air thru the rad to keep a V8 engine
cool. Especially a high perf engine. Get a good OEM GM 7 blade heavy duty A/C clutch fan.
Get the crank pulleys and water pump+alternator pulleys and belts too.
Don't forget the fan shroud. If the fan clutch bearing is gone, replace it.

80's GM V8 pickup or Mid 80's camaro firebird with carbed 305 V8.

Silverback 10-26-2010 01:19 PM

As with most things, it depends...

Converting mechanical energy to electrical energy and back is never a good for efficiency (Every conversion there is some loss that is dissapated as heat, sound...), but on the other hand, most engines don't need a fan all the time, and an electric fan setup can adjust for conditions faster than a clutch fan, and even with a clutch, when it's not needed a mechanical fan exerts drag on the engine using some power.

The end result is that the more the engine needs the fan, the less likely you are to gain something by going with an electric fan. If it only needs one occasionally, then you're better off going electric, where if it needs one most of the time, mechanical.

The second consideration is that mechanical fans tend to be both simpler (less likely to fail) and can move MUCH more air than electric fans (it has a few hundred hp worth of engine driving it, where the electric fan has a fraction of a hp motor on it). Basically if you need heavy duty/bullet proof go mechanical (RWD police and other fleet vehicles typically will come with a large mechanical fan even if their civilian counterparts come with an electric fan)

Bracewell 10-27-2010 06:55 PM

I't's going on a 406. I live in Florida. I bought the biggest, baddest radiator they build. Also have airconditioner. I'll stick with mechanical. October 27, @ 9 o clock. 78 degrees. It got up to 90 today. Thanks Lee

ap72 10-27-2010 07:36 PM

Use a stock mechanical fan with a clutch. Those fancy flex fans are junk. A clutch fan in good working order is great!

aintmisbehavinn 10-27-2010 08:02 PM

Maybe a tenth, my motor is more responsive without logging a huge fan 24/7 for no reason, free wheeling or not. Made 0 difference in my alternator because it hardly ever runs, just when I stop in intersections and it's adjustable, in or out, switched so I can manually engage or I can run it in the staging lanes to cool things down while waiting for the burn box.
One huge 14" fan keeps my cammed 350 between 160 and 180 all day on the hottest days, one of the best mods I even did was taking that stupid mech fan and huge drumlike wind tunnel cave off and running a steamline Durale. I can reach everything without the mech dumbell. It takes HP to turn a fan on the end of your cam, mine runs cooler and seems to spin quicker. All the new stuff is going electric.

I would recommend it just for the instant response and options vrs the old style power robbing one direction on all the time junk from the factory.

Miley Tipton 10-28-2010 04:08 AM

hi everyone,
Every fan has to do mechanical work and thus loss lots of energy as heat and mechanical energy, Whether you choose Electric motor or Clutch Fans both have to do mechanical work, So some power loss will be there, but as considering the other factors you should go with Clutch Fans... Thats my personal personal opinion.

Thanks

75gmck25 10-28-2010 05:04 AM

Most folks with hot rods prefer a stock clutch fan and good shroud instead of an electric fan. However, I think that is because the air flow of many add-on electric fans are over-stated by the manufacturer, and they don't work as well as the claims. You may gain a little HP with an electric fan under cruise conditions (no need for the fan to be on), and the engine seems to spin up a little faster when it does not need to move a fan, but you also need a strong alternator to keep up with the amp draw when the fan is on high.

I have a Ford truck with 5.4L engine and clutch fan, and a 2005 Mustang GT with a 4.6L engine and OEM electric fan, and I do not see any difference in the cooling system's ability to keep up with Texas heat. However, my electric fan is a Ford factory system that is designed to take the heat load. Many conversions use relatively cheap fans with shrouds that don't cover the radiator very well.

Bruce

80ta 10-28-2010 05:15 AM

Most tests I've found by searching alternator loads is about 1.5 hp. Mechanical fans I believe take more, espescially at 6000 rpm

check this link. http://www.carnut.com/ramblin/dyno.html

Shelby1 10-28-2010 06:36 AM

Bracewell look at this post http://www.hotrodders.com/forum/wwil...-a-183860.html post #9
I picked up almost 2 miles per gallon,much faster rev up and over all better response time buy doing the conversion. The mech fan weighed close to 10 #,but if you convert a vehicle that has one of the new plastic fans you won't notice any difference. But I am with the rest of the guys,if it's a DD where most driving is slow.....stick with the stock fan.
Good Luck
Kenny

pitts64 10-28-2010 07:24 AM

If you have a clutch fan, I would keep that....

dsgb610 10-28-2010 10:30 AM

Flex fans
 
Sorry not trying to hijack but while we are all here how do you guys feel about Flex Fans?

Irelands child 10-28-2010 11:13 AM

Quote:

Originally Posted by dsgb610
Sorry not trying to hijack but while we are all here how do you guys feel about Flex Fans?

Fine - if they don't come apart - which the are prone to do :pain: It doesn't happen often, but I have seen two fail. One did significant hood damage, the other, came very close to hitting a guy tuning his engine. The failure causes - unknown, but my guess high cycle fatigue.

Dave W


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