M0178 Cheap Pneumatic to Electric Fan Conversion

OD Green

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Hello Troopers! After buying my 2nd NOS, (New Old S#$t) pneumatic fan clutch that arrived missing parts from one of the military parts boneyards I started experimenting with electric fans. The first attempt failed, it was a 15" Flex a Lite rated 3,300 CFM. Too small as was the hole I cut in the DIY plenum. The 2nd attempt went much better, I bought a brand new Crown Victoria fan for $40 bucks on Craigslist. Unsure on the CFM, which really needs a pressure rating to be meaningful.. but some believe it's about 4,000 CFM. It's a two speed fan that I think pulls between 40 and 50 amps. It's an 18" diameter with S shaped fan blades. Today's test was at over 90 degrees ambient temperature and 20 miles on the highway at 55 mph. I ran the fan on high the once the temp got to 190. The truck never went over 200 degrees, Once I got off the highway I was back down to 180 in 4 mins. And while this modification isn't for everyone, it's working for me, at least for now. The fan is presently manually controlled but I have a TS-139 dual temp themostat switch on the way, I'll keep the dashboard override switches in place.
 

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simp5782

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The kitty cat runs at 195 degree operation temp. So running 190 or higher on the highway is alright with your fan on. Running Below 190 while even driving around town will show lack of efficiency on burning fuel. Also the closer to 200 degrees your oil temp is the less moisture it will have. Truck should be at operation temp when driven due to the heat load to prevent cylinder scoring

Going with an air to air transmission cooler and deleting the heat exchanger takes a tremendous heat load off the engine
 

OD Green

New member
7
6
3
Location
Massachusetts
The kitty cat runs at 195 degree operation temp. So running 190 or higher on the highway is alright with your fan on. Running Below 190 while even driving around town will show lack of efficiency on burning fuel. Also the closer to 200 degrees your oil temp is the less moisture it will have. Truck should be at operation temp when driven due to the heat load to prevent cylinder scoring

Going with an air to air transmission cooler and deleting the heat exchanger takes a tremendous heat load off the engine
Thanks for the post, I put in the two stage thermostat yesterday- works perfect. At about 75 degrees outside I drove about 10 miles before the low speed came on. Only at one point did it switch to high speed. Once off the highway and on back roads it cooled low enough that the fan turned off. I wired LEDs to the relays and brought them out to the dash to know what's going on. I need to clean up some wiring, put the LEDs in the dash switch box, but this looks like a permanent mod for "Blackout". It might not be for everyone, but to my view a Crown Victoria fan moves enough air to keep my M1078 happy under the conditions tested. I don't know how it compares the OEM fan, but for my needs it's a great solution so far.
 
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