The low speed would be plenty an put a 180 stat in or lower . I run mine a low all the time though a toggle switch wired to a Ignition on power source. I never have had to use the high setting the T-bird /mark 8 fan does move a lot of air . When it get in the 90's I run at 190 all day long! I have never had a overheating problem since I have done this conversion . Just make sure you use 2 relays.

 

I'm sure it'd be fine to run it only on high and leave low disconnected. If I were going to do it that way I'd at least put in a cheap thermostatic control so that it didn't even kick on until a certain temp though.

 

I've wanted to do this for my F100 for quite some time, but I am concerned how it'd be to tow with.

 

FTE users! Thank you so much for all the great info on this mod. I'm a new user and new owner of 73 F100 390 Automatic w/ factory AC. I cannot get my 73 to stay cool - Granted it's 100+ in AZ but I cannot get it to run normal temps, tipping the gauge to extreme. Using OEM fan clutch, installed fan shroud, new stat, new radiator copper/brass big'un 24 1/4" and now contemplating electric fan. This thread has helped greatly and I sure do appreciate all the words of wisdoms. With such a larger core, any idea of elect fan, with some slight fab work that would be best?

 

Hi,Welcome.I have never had great luck with electric fans keeping big engines cool. I run a 10 to 1 460 in my 79 bronco. I live near sacramento,It sees 90-100 degree heat Never gets hot even with the a/c on. What thermostate are you running? Is the HD fan clutch working?(can you hear it come on?) Have you used a thermometer in the radiator to seee what temp its running? Scott

 

Ever hear of the Lincoln Mark VIII/ TBird fan?

Josh

 

Scott - Thanks so much for the reply. I was concerned about that, plus I'm planning to use my 73 to tow the boat rather than my daily truck, ashamed to say what that is, LOL, so I want to be abosultely sure. I'm using a 195 degree superstat. The HD Fan clutch is working great. I haven't tested the temp yet, I plan on doing that tonight. If there's any other gotchas you might be able to share that would be great. I'll post an update later tonight along with my pics. Thanks again!!!

 

Hi,I would use a 180 degree. It should read 1/3 to at the most 1/2 of the factory gauge (providing it is somewhat accurate) hope it helps,Scott

 

The factory gauge does a better job of telling the outside temp than it does engine temps.

You want the 195 t-stat with a high quality radiator.

The Mark VIII electric fan is considered the BEST fan for the job and shouldn't be confused with aftermarket rinkey dink electric fans. No matter if that garbage cost $50 or $500 they do not hold a candle to it.

Josh

 

With the summer temps climbing I would like to report the the Mark vIII / T-bird electric fan on the low setting has performed flawlessly an the truck stays cool! The electric fan upgrade is one of best! I will be doing this to my bronco .

 

I live near Sacramento too and am running a mild 460 in my f250 4x4. I am running a desert cool radiator and a mark VIII fan controlled by a delta curent control. My motor temp stays pegged once she's warm right at 190.

 

Towing anything?

 

Yes I tow with the truck an haul heavy load's ,plus in the winter time I plow lot's of snow.

 

After all my tinkering, I've decided to try the Mark VIII so I'm off to the yard to see what I can find. I did get the temp down with a new 180 thermostat which is nice, but running the A/C and idling it's a little hotter than I like. Thanks again for all the insight!

 

I've had a few issues with engine temps varying more than I'd like but after reading this article I only use balanced thermostats and they do make a difference.

Performance Unlimited 4-Wheel & Off Road Center - Hartford, Wisconsin - USA