I've read the fan threads/articles under the Technical Info Hyperlink concerning electric fan conversions. It seems that there are some different fans of choice that CAN work. Which one seems to be the best fit?

On another Mustang forum I'm on, most folks swear by the Mark VIII or the Contour fans. I'm thinking since the F100 radiator is downflow and more square that a single fan may be best. What I would like to do is incorporate the metal flanges on the sides as a way to mount the fan, whichever one I go with. Suggestions about how to use the actual fan mounts for that?

 

I fabricated custom brackets to use the Mark 8's ears. The lower mounts.are.just saddles and two bolts is what holds it in place. Visit my 70's build thread.

 

I would recommend the Mark VIII fan. They are easy to come by, cheap, and most importantly they move a lot of air. I trimmed the plastic shroud so it isn't as thick, but other than that, you'll just need to fabricate a few brackets like HIO suggested. Pretty straightforward, I just used some bar stock I had laying around.

Here's how I did mine, and it's mounted to a 351 radiator (not sure which rad. you have in your F100).

 

Thanks guys. HIO, are you referring to the lo-buck bumpside or another build thread?

The radiator is just a stock replacement one for a 302 ci standard trans.

 

Okay, so page 7, post 256 of the LBB. Very nice HIO. Looks like that fan is made for that size radiator almost. If I have trouble finding a Mark VIII fan, isn't there another alternative with the same dimensions just a different motor? Like maybe the Thunderbird/Cougar or Taurus fan?

 

Yeah the lo-buck bump.

.. on another note, I got stuck in a massive backup in SF. Made me decide to go with an auto trans and overdrive in my 71 F250.... plus a 3g alternator, dual batteries, Mark 8 fan, and oil coolers.. ya know, typical upgrades.

 

i got mine from a Thunderbird. same fan.
that day i got the fan, 3G alternator and the Volvo relay for $60 from the yard. i can get $10 back when i return my alternator.

 

Right, we've got some upgrades on this 75 F100, not many, mainly in the motor. I'ts still running the mechanical fan with no clutch but we're looking to do some other things like the 3G alternator and the electric fan. A 5 speed would be nice too. And I'd like to upgrade the brakes to power.

I've scoured over every page of your LBB build, thanks for the inspiration.

 

Thanks, I thought I remembered something on that. What years apply for the Thunderbird?

 

its the late 90's body style. mine came from a 97.
i use this site for cross referencing years and models. plus it can show what yards in your area will have the item you are looking for.
Car-Part.com--Used Auto Parts Market

 

How did you wire up the controller or is it just a fan that runs all the time?

 

It should be 93-98, IIRC. The fan cfm may vary slightly by year/model, but a fan from a 93-98 Mark VIII or Thunderbird will do the job fine. Also, Lincoln Continental's of the same year range have very similar fans (used one of them on a different vehicle) that would work.

I've got a Hayden fan controller for it, but have not yet wired it up.

I currently have it wired to a switch on the dash with a 70 amp Ford relay that you can find in Focuses, Mustangs and most other Ford cars of the late 90s/early 2000s. It's actually the electric fan relay for those cars. The fan has a lot of startup draw, which is why I opted for using a 70 amp relay. I would also make sure to use a nice and heavy gauge wire.

I would also recommend a 3G alternator swap before adding one of these fans.

 

The Taurus or Mk8 fan would be ample fan for you. Use a bmw thermo sensor to trigger it on low and high. That switch will sit in your upper radiator hose. You can purchase one from Holister Road, a guy on ebay for about $45, or buy one for $12 and tap it yourself. The one from Holister road (website too) has two holes so you can run a spare switch. Oh, and when at the J/Y pull an extra volvo relay pack for a spare.

Things to remember: The wiring is as important as the fan. The newer fans (from the 90's) draw less amps. Use 10 gauge for the + wires. You can get an 80 amp continuous use relay on ebay for $13. Use the Volvo relay. It prevents cold starts of the high speed from a stop that can cause a power spike of over 100 amps and fry relays. Some guys run a 40 amp relay with the Taurus or MK8, along with the volvo control. I prefer over kill since these fans routinely spike well over 40 amps.

My favorite quote regarding the Taurus fan: "This thing will suck a cat through the grill."

The MK8 is the most powerful--moves the most air. However, the Taurus fan moves 2500 cfm on low, and 4500 cfm on high, with is more than enough. Make your decision from the amount of area each covers. Having said that, let me also say that I had an efan on that covered less than 1/3 of my radiator and it cooled fine, so ....

One other note: If you're running an electronic ignition like msd or another brand, then you need to be careful of where the unit draws juice. When the fan starts there is a rush, a spike in power sucked to the fan and your ignition may miss or hesitate. Your fan wires should be downstream of the ignition feed. That is my experience with a 130 amp alt.

If you go with a thermo switch in the rad. hose, be aware that they will kick in about 13* hotter than they are rated, so a switch said to open low speed at 195* will not open before 208*.

The Contour fan is a dual set up. I've been running one for about two years. Although Ford set it up with a coil resistor for a two speed application, that is impossible without the oem wiring harness, so it used as a single high speed fan. It moves 3500 cfm. It is a great fan for an installation with space restrictions. I have an I6 engine and that is why I use it. However, I'm missing having the extra speed the two speeds deliver and am now trying to configure a Taurus fan for use.

One other option that is becoming popular is the Volvo fan. Ford put the Taurus motor on early 90's volvos, but configured it differently. It is slightly smaller in blade diameter, with one less blade as well. The fan has a thinner profile as well. There are videos on youtube about it. It is quite surprising the volume of air it moves. Note that it has the same blade design as the Taurus fan. The later 90's models have a different blade design.

There are many threads about the install using a Taurus/Mk8 with volvo relays. Just google it and read. Most include a wiring diagram as well.

 

Thanks for all of the responses. I'll probably try to find a Thunderbird fan, seems like that will be easier to find in a salvage yard. What I would like to do is run some sort of controller with a temp probe that has a soft start to help with the initial amperage spikes. I'm not too good with wiring but I can follow a diagram pretty well.

 

I also am needing to go to an electric fan on my 78 - 351w due to having no shroud on my clutch fan and heating up at idle. I want to use the Mark 8 or Thunderbird style which should be readily available here in the yards in my area. My question here is what is the easiest fan controller option. You guys talk about a toggle switch, but Is that just an override? I am clear on the fan and install but need help on the controller. Thanks, Mike