Electric Fans,...More Power...?

[Darrin Tosh]

I know this has been beat to death, but check this out,..

I was at the auction today and drove a beat up POS 345,000 mile 1992 F350 CC 4x4 7,3 NA Automatic. IT was a used up ole farm truck, but the motor was strong.

On the test drive I stomped on it pretty good, and the back tires just broke loose like I was driving a big block gassar. I thought why is this truck so peppy. I did it a couple of times, and was amazed at the power of the NA IDI. Keep in mind that I drove a NA IDI for a couple of years with LPG Dual Exhaust, Banks Power Pac etc, and was no where near as peppy as this one.

I poped the hood, and found that it didn't have a fan on it, just a homemade fan shroud with 2 electric fans built in with some relays, and fuses. It was actually a pretty nice job.

Would not running a fan get you THAT mutch more power? Not that I will be changing my fan out, I just thought it was interesting.

What do you think?

 

[93turbo_animal]

Darrin I've seen reports of 15HP on a gasser and if you have ever compared our fans to a gasser ours are huge so it wouldn't suprise me if it would free up 30 HP or so

 

[rancherman84]

i've heard on other sites and from other people that the electric fans will not keep up under heavy loads

 

[Carl_F350]

What about a fan from a Greyhound bus or some other larger diesel application? I passed a Greyhound the other day, they have two separate fans and one of them looks like it would fit. I'm trying to find a Bus junkyard to check it out.

 

[Carl_F350]

I'm not sure I passed it on the highway, but I know the fan looked bigger than 15".

 

[Max Power]

How much CFM from a clutch fan?

 

[Nickbf2504x4]

lets get someone on the dyno and test it out then we can all ditch our cluctch fans! :Sly

 

[Agnem]

I guess the question I would have is even if the electric could handle the cooling requirements, what's that 30 amp draw going to do to your alternator? Seems somebody should try something. I've always believed an electric could work, if the right one were found. Those pusher motor homes have a radiator/intercooler package on the side, and I'm pretty sure they have electric fans on them.

 

[DLSF350]

I think you are on to something here. I was always surprised/disappointed with how much power my truck loses when it gets hot (85*+). I tow primarily in the summer and thought the hot intake air was killing the power on my NA truck. I read that the 7.3 puts out 104 hp @ 2000 rpm (my cruising rpm), and explains why a 30' trailer with 8.5x10 square front is limiting the truck to 62mph. I know that changing out a lightweight 19" flex fan for twin electrics on my drag race car netted 26-28 hp, and cooled better. The two 12" electrics moved more air up to 4500 rpm. 100hp less 25 hp for the fan and the AC on full blast (5 hp) in 90* weather = no highway towing speed.

 

[Agnem]

It would certainly make an interesting experiment. You could take your fan off, with a cold engine, and do a few test runs. Once it got to operating temp, put the fan on it and try again. No need to buy the electric to find out what the fan is sucking up.

 

[93turbo_animal]

even though the electric fans would add some draw the alternator will only pull so much and not nearly as much as the propeller we call a fan. I noticed that before I replaced my IP and turned it up that pulling a load I could really feel when the fan kicked inso it has to be robbing a bunch of power I have also heard that electrics would not keep up but I'm not sure why we have such a hard time keeping our trucks cool just pulled the radiator on an International with the PSD and that radiator was half the size as ours

 

[The Warden]

One other thought...those fans might make a good pusher setup, mounted in front of the a/c condenser to get good air going over the condenser while at a stop. My M-B has a setup like that, and while it's not meant to replace the engine-driven fan, it does a decent job of making the a/c work better, and can be used to cool off the radiator (although not as efficient as the engine-drive fan).

Just a thought...personally, I'm all for leaving the engine-driven fan in; why change it if it works just fine as it is?

That said, do you know if they plan to make a setup meant for an '80-'96 truck?

 

[JPR]

That said, do you know if they plan to make a setup meant for an '80-'96 truck?

Dave says they are still testing and did not have a final design yet, so I did not ask about the specific applications. In reference to our IDI's, he said that our fans move a lot of air, emphasis on "a lot".

 

[The Warden]

In reference to our IDI's, he said that our fans move a lot of air, emphasis on "a lot".

I hear that! That's why I would really just have the fans set up to run with the a/c (like have them turn on if the pressure gets too high or something on those lines; haven't gotten that far yet, though) and keep with the engine-driven fan to cool the radiator down when needed...

 

[yARIC008]

I understand the need for a fan at low speeds, but at high speeds does an engine even need a fan, like.. it's 70mph winds flying at it just from driving enough to cool the radiator?