Replacing 4Runner fan clutch with electric

[GasSavers_Red]

Originally Posted by Mentalic

Finally installed the fan today, took most of the day as well. Only ran it a bit to verify operation so I don't know the FE impact just yet. I removed the lower grill block until I feel confident in this new setup.

First thing I did was test the Spal fan and controller, good thing I did. It was not calibrated at all and ran full speed at power up. The paper work indicated it was set up to work with the Spal temp sensor from the factory at 160F on, 200F high, yet mine was not.
So I had to calibrate mine, and to make it easer I removed the sensor from the truck and rigged up a hot water bath so I could set the low speed turn on at 155F and full speed at 195F. Its not had to calibrate, just get the sensor to proper temp and press the low or high button.

The original fan was 18" in a 21" cutout.


Installed the Spal controller behind the battery tray on the fender.



New Spal fan mounted in stock shroud. Used some aluminum sheet and reinforced the stock mounts because they looked flimsy.



Front of new fan. Looks tiny but man it moves some air!.



Fan installed in truck. Fits with no problem.



Temp sensor mounted on radiator outlet line. Its wrapped with rubber tape and topped off with regular electric tape to insulate it so it picks up the temp better.



Top view where you can see the shaft that gave me clearance trouble with the Mark 8 fan I had originally tried to use.

click free...nice setup

[GasSavers_Red]

Originally Posted by Mentalic

Finally installed the fan today, took most of the day as well. Only ran it a bit to verify operation so I don't know the FE impact just yet. I removed the lower grill block until I feel confident in this new setup.

First thing I did was test the Spal fan and controller, good thing I did. It was not calibrated at all and ran full speed at power up. The paper work indicated it was set up to work with the Spal temp sensor from the factory at 160F on, 200F high, yet mine was not.
So I had to calibrate mine, and to make it easer I removed the sensor from the truck and rigged up a hot water bath so I could set the low speed turn on at 155F and full speed at 195F. Its not had to calibrate, just get the sensor to proper temp and press the low or high button.

The original fan was 18" in a 21" cutout.


Installed the Spal controller behind the battery tray on the fender.



New Spal fan mounted in stock shroud. Used some aluminum sheet and reinforced the stock mounts because they looked flimsy.



Front of new fan. Looks tiny but man it moves some air!.



Fan installed in truck. Fits with no problem.



Temp sensor mounted on radiator outlet line. Its wrapped with rubber tape and topped off with regular electric tape to insulate it so it picks up the temp better.



Top view where you can see the shaft that gave me clearance trouble with the Mark 8 fan I had originally tried to use.

click free...nice setup

[ZugyNA]

Originally Posted by Mentalic

Finally installed the fan today, took most of the day as well. Only ran it a bit to verify operation so I don't know the FE impact just yet. I removed the lower grill block until I feel confident in this new setup.

I'm going to be adding 2 smaller fans to a 4 cyl Nissan 4x4. Only issues I see with your setup is that by shrouding the fan...you might reduce the airflow you have from just the truck moving forward...though your efficiency is increased when the fan runs.

I'm going to be using a mechanical adjustable fan switch where I put the sensor bulb (covered by silicone gasket goop) inside the coolant hose coming from the engine. I adjust these on the road by watching the temp gauge...I only want the fan to run if the gauge starts to rise above normal. This switch is on/off at one temp.

I also use a fan indicator light so I know when it is running.

I find that placing the sensor on the outside of the rad or a hose does not allow very accurate control of the fan.

My opinion is to max out the natural air flow as much as possible by not using a shroud...and be sure the fan(s) only run when really necessary. Otherwise you run the risk of spending time and $ and might be not much better off than you were mpg wise. Not using a shroud might cause overheating on the trail though.

But I haven't actually done this yet...so who knows. The fan switch I have installed in another vehicle and it works as expected....rarely runs.

[Mentalic]

Originally Posted by ZugyNA

Only issues I see with your setup is that by shrouding the fan...you might reduce the airflow you have from just the truck moving forward...though your efficiency is increased when the fan runs.

I

Yea I realized this and its the reason I removed the front lower grill block to get more pressure on the front of the radiator. Flow is driven by differential pressure so since I now have a smaller air hole I adjusted the pressure.
Think I'm going to box in the lower section in front of the radiator to prevent it from leaking air down under the truck. Blocking this section up would be sorta like a grill block as it would reduce the air flowing through the grill, likely not as effective as the block though.

From running the truck yesterday I found out that if your moving at all I don't need to run the fan even for the A/C. I installed a switch on the dash that I use to disable the fan from automatically running when the A/C compressor is on. The plan was to switch off the fan for highway speeds but there is evidently so much air being rammed through the radiator that its just not needed unless sitting in traffic.

[Mentalic]

Originally Posted by ZugyNA

I find that placing the sensor on the outside of the rad or a hose does not allow very accurate control of the fan.

Trying to read the temp on the outside of a rubber radiator hose would definitely not work. Using a hand held IR thermometer the hoses read 20-50F lower than the metal they connect to. Where I'm reading the temp is metal and I'm using a flat brass clamp that gets good contact. For good measure I also applied heatsink compound for better heat transfer. Monitoring the pipe with the IR thermometer the radiator fan switches on within a couple of deg where I calibrated the Spal controller to activate. Worked better than I expected actually.

[ZugyNA]

Originally Posted by Mentalic

Think I'm going to box in the lower section in front of the radiator to prevent it from leaking air down under the truck.

My guess on this is that you could create a kind of ram air intake for the rad that would force much air into the fan opening you have as possible...any excess would spill out over the front of the cowl and flow back?

My 300ZX had a rad that was tilted forward about 45* and had an opening above the air dam that forced air up into it. When I added an extension down from the air dam and blocked this opening...it overheated in winter. Partial vacuum?

Guess you need to go with the design...but efficiency is the name of the game.

[Mentalic]

After two days running the E-Fan the numbers don't look too good. Absolutely no noticeable FE difference under 60mph at all. At 70mph there begins to be about 1mpg advantage from my old numbers though. Since my daily drive never gets over 50mph this mod had no FE benefit on my truck.

Obviously, the Toyota thermostatically controlled fan clutch must work very efficiently. I had thought this type of result was a possibility from the start but still I had to give it a try.

[GasSavers_Red]

Originally Posted by Mentalic

After two days running the E-Fan the numbers don't look too good. Absolutely no noticeable FE difference under 60mph at all. At 70mph there begins to be about 1mpg advantage from my old numbers though. Since my daily drive never gets over 50mph this mod had no FE benefit on my truck.

Obviously, the Toyota thermostatically controlled fan clutch must work very efficiently. I had thought this type of result was a possibility from the start but still I had to give it a try.

That almost matches my unofficial data. At highway speeds I didn't see a change between my mechanical fan and the e-fan, under 30 I would see a +1 MPG but nothing consistent.