Replacing 4Runner fan clutch with electric
 

Well, I finally decided to make the switch on my 4 Runner from the thermo fan clutch to an electric radiator fan today. Found a used Mark VIII electric fan and ordered a variable speed fan controller for it today. I went the variable speed unit since I can adjust its temp setpoint to where I want, that and I just like to control stuff. :)

I'm hoping to accomplish two goals with this change.

One, the obvious one, improve FE by reduced parasitic load.

Two, increase my engine temp a bit by increasing the radiator outlet temperature. I've checked my existing setup and found that my radiator is really over cooling the water outlet temp. On an average 95f day the outlet is about 115f now with a 180f inlet. Its also taking a long time to get my engine up to the upper 180's on the Scangauge and almost never sees 190f.

Between the two, I'm hoping for a 2 mpg improvement.

I'll post some pic's when I finish.

Most people have a lot of trouble with variable temp controllers. I would stick with a standard automotive switch. Good luck.

I'm watching your results. I too have a belt driven fan and have wondered what the FE gains would be by going with an electric fan.

While continuous control is no doubt more complicated compared to an on/off switch the benefits outweigh the increased complexity in my mind. Being able to adjust the temperature control setpoint is something I must have for this project to reach its full potential. Also its only going to run the fan as fast as required to maintain the outlet water temp at setpoint so its going to reduce amperage load spikes of the fan switching full on.
Another thing about the controller I will be using is that it will run the fan at 50% speed when the A/C compressor is running. For my application this signal input to the controller will be the compressor clutch.

I'm using a 35amp controller from here: https://www.dccontrol.com/

If it turns out to be a POS I'll be posting it here! I have seen this company's products used on other forums so its not a blind choice.;)

I run the DC Fan controller on my Jeep. Its a pretty well designed piece; easy to setup and use and its cake to wire in an on/off switch to it. Plus its survived a few dunks in water, along with sand and rock dust without blowing anything.

What temperature thermostat are you running Mentalic in the 2 Runner? If the inlet is only seeing around 180F I don't think you have a 195 degree themo installed. Switching to one of those could boost you another few points in the FE department.

FWIW my inlet temp comes in around 200-215, outlet around 130-150

On the part about towing, granted I've got a block built in the 80s, but the Mark8 fans can't move enough air when you are climbing a grade. I haven't overheated, but its gotten fairly warm.

The problem I had is I could only find stock temperature setting thermostats from even the non oem parts suppliers, and thats 82c/179.6F. I recently replaced the original stat and the new one runs the same temp as the original did or maybe a degree less... Now the Scangauge temp gets up to 190 every now and then when I come to a stop towing then drops quickly to 186F. It runs 186F on the Scangauge just about all the time after the first 10 miles, just about when I get to work its warmed up. :(

I also suspect the radiator in my 4Runner may be the same one they use for the v8 engine and I've got the v6. The radiator outlet temp has only been 115f when I have checked it. Another thing thats seems odd is that the thermostat is on the lower end of the engine and takes in the cold line from the radiator directly on top of the thermostat! Seems like on older vehicles that I actually paid attention to were set up just the opposite way.
So the thing is that since the temp control point is low on the engine may have something to do with why they run the lower temp setpoints on the thermostats?
The Mark 8 fan is a two speed unit, is that the one your using and if so which speed are you using?

Since it does take the radiator outlet water through the t-stat rather than the inlet thats probably why it has a cooler temp range. Kinda weird though since every other car or truck I've worked on has it the other way around.

Mines the 2 speed as well. I forgot exactly how I wired it, but I think I hooked the high speed wires to the controller. I can check in the morning for you if you want.

My bad. I misread your original post. I thought you were talking about a simple variable temp switch. The kind you stick between the radiator fins. I've head good things about the delta controller but never tried one. Interested to see the results. Good luck.

Reason I asked is I have seen several Tacoma install's that only use the low speed and its was plenty enough for there 3.4 v6's which is the same thing I'm running.
Hows your fan shroud fit? Does it cover the whole radiator? Just seems like it should do the job from all the postings I've read.

I've seen a video of an Mark8 van on high, its VERY loud, sounds like a light aircraft on takeoff! Don't actually have mine yet, its on the way. If you happen to take a look at your fan please note the wire colors you used. Figured Id just have to check the windings with a ohm meter then test it.

Well my Mark 8 Fan came in today. I must of had the Mark 8 and Taurus fans confused since the Mark 8 is a single speed unit. Sort of simplify the wiring issue. :)

Waiting on the Dc fan controller....


This thing moves a ton of air!
https://img509.imageshack.us/img509/232/mark8fankx1.jpg