Radiator Fans Wars: Electric vs. Mechanical or Both!

[TemboTusk]

I have had a 350/383 tbi 5.7 v8 and in my wagon for about 3 years. During that time I have run a Contour double fan on the radiator. It is a perfect fit dimensionally. Around town, on the local freeways the temp is always at 180 degrees. I live in the SoCal area and the terrain is level.

If I run out to the desert in 100 plus temps or pull a load up a hill, the electric fans just don’t keep up. The temp goes over 220 plus. I have a new 4 core three pass radiator, new water pump, new 383 engine etc. Everything is in good working order.

I have installed a mechanical fan with a clutch in addition to the contour fans. The temps around town have dropped 20 degrees. I have not tried it yet in the desert, but in 95 degree temps the gage reads below 180.

My question: should I keep the electric fans along with the mechanical fan or remove the electric fans and install a shroud for the mechanical fan?

Second question: will my stock Toyota shroud work or should build a new shroud? I have a 1985 FJ-60 and my stock shroud is metal. I have plenty of room between the radiator and the mechanical fan. The fan will be outside of the shroud. It lines up more or less with the opening of the shroud. Not perfect.

Thanks for any input!

 

[Bret]

Cooling is covered a lot, try searching in the 40 section too. As a general rule if you are at speed and have trouble cooling you may need more surface area with your radiator.

 

[Elbert]

Post up some pictures... You say you have plenty of room between the radiator and the mechancial fan. What type mechanical fan are you running, stock GM type?

I have a similar setup but use the large alumunium radiator from MAF. Mine runs aroun 190 degrees in town and will climb to to 200 or 210 or so, on long pulls off road ..but does cool down. I run a 180 degree thermostat. Truck will generally run around 180 in the winter and 190 in the summer.

I have the 5.7 vortec and I don't have much room at all between the radiator and the hub of the water pump. I used the advance adapters bellhousing and engine mounts, no mods to drivetrain.

I don't think the stock yota shroud will clear your GM fan... I would want the fan to fit partially inside the shroud to improve the flow across the radiator. Look at soemthing like a 99 GM pickup or suv to approximate that setup.

Don't see any harm in leaving the electric fan on there...for low speed cooling, but you might gain some effeciencies in air flow my removing the electiric fans, and getting a good shroud setup for the mechnical fan.

I've run a large 16inch SPAL fan behind a radiator along with mechanical fan setup with no adverse effect, but I think the SPAL fan setup allows more air flow through its "body" than does the Contur fans. I also use the dual ford contour fan setup, as it looked like a GM fan clutch and fan would not work due to clearance issues with the radiator and fan. Plus I don't think we got my engine sitting just square with the radiator anyway.

Assume your engine sits back from the radiaotr a good bit, as you describe your setup.


I would love to install a large radiator in the 60, but without a lot of fabrication to the radiator core support you are not going to be able to do that, also you might have to sacrifce your A/C condensor as well.

I've not seen a 100% solution for cooling with V-8 swap anywhere. I would say that if you can adapt or use a GM mechanical fan setup and fab up a good shroud you should not really have cooling problems....except you might have issues with air flow across the radiator at low speeds and idle conditions like you encouter off-road quite a bit. Electric fans are great for this..

I know there are some other guys on here with V-8's too?

I also have an aftermarket 4 core brass radiator I bought from Autozone (direct replacement) that I setup with a large 16 inch SPAL fan that works good, due to the size of the OEM style radiators...could only fit one 16 SPAL fan.... When I did my engine swap I decided to go with the dual electric fans and aluminum radiator, as my setup would not facilitate a mechancial clutch fan, to the extent I measured and looked... I might have had around 1/4 of an inch clearnce between the fan and radiator and that was too close.

 

[TemboTusk]

I really like my Contour fans as it opened up a lot of room up front. Around town and locally the temps never go over 180. It’s only when I take a long trip and over time the heat creeps up and up. Just not enough CFMs.

I’ve attached a picture. I’m using a standard 6 blade GM fan. The fan is 5 inches away from the radiator. I used a Downey bell housing and fabbed a cross member fix when I installed the v8.

I think the radiator is more than adequate to do the job. It is a matter of getting enough air to flow through. The GM fan sounds like a wind turbine at 2000 rpms. I’m currently having trouble getting the temps above 160 around town. The engine never really warms up with the GM fan. I’m sure I have solved my high heat issues.

My worry is that the Contour fan shroud may be blocking good air flow, but than again, if it is hot, the fans run. With the Contour fans, the GM fan does not have a shroud, or maybe the contour fan can act as a shroud. I don’t know.

So, the real question is: Should I just leave the electric Contour fans in with the mechanical GM fan or remove the electric fans and install my stock shroud? (The stock shroud is 3 inches thick. The GM fan will still have 2 inches of clearance between the shroud edge and the fan.)

 

[Elbert]

I think your mechanical fan may be working overtime due to air flow restrictions, but thats just a guess.
I would want a fan shroud to make the mechanical fan more efficient, and then you migt want to remove the electric fans to see what happens.

Its not too big of a deal I would remove the electric fans, install a shroud for the mechancial fan and see what happens. I know on my GM trucks...the fan is at least 3/4 of the way in the shroud. You may have to figure out a way to do that, as the shroud is not effective unless the fan is at least partially inside the fan shroud opening. I'll take a pic of my yota and then one of the suburban to show the mechanical fan setup on it.

Your engine sits back from the radiator more than mine does.

One note on the GM fan clutches....they do make some noise....but that tells me its working and the temps reflect that. I have an 01 suburban with 496 and you hear the fan clutch come on and off throught the day when its hot and driving around town. Fan clutch is brand new GM and truck never runs over 195 or so. If it's not making noise, then you have problems because you then know the clutch is not working, and most likely you'll see your temps rise.

ON another note...do you have your A/C working?

 

[TemboTusk]

I think your mechanical fan may be working overtime due to air flow restrictions, but thats just a guess.
I would want a fan shroud to make the mechanical fan more efficient, and then you migt want to remove the electric fans to see what happens.

Its not too big of a deal I would remove the electric fans, install a shroud for the mechancial fan and see what happens. I know on my GM trucks...the fan is at least 3/4 of the way in the shroud. You may have to figure out a way to do that, as the shroud is not effective unless the fan is at least partially inside the fan shroud opening. I'll take a pic of my yota and then one of the suburban to show the mechanical fan setup on it.

Your engine sits back from the radiator more than mine does.

One note on the GM fan clutches....they do make some noise....but that tells me its working and the temps reflect that. I have an 01 suburban with 496 and you hear the fan clutch come on and off throught the day when its hot and driving around town. Fan clutch is brand new GM and truck never runs over 195 or so. If it's not making noise, then you have problems because you then know the clutch is not working, and most likely you'll see your temps rise.

ON another note...do you have your A/C working?

The Contour fans causing restrictions was my biggest worry. It seems very redundent to have both electric and mechanical fans. I think I will remove the electric fans just to see what happens. I hope the stock shroud works good. I don't really want to make one.

My A/C works great. My requirements are that the A/C works, up hill at 110 degrees ambient and the engine temp not be higher than 195 degrees.

 

[Elbert]

how are you controlling the cycling of the compressor on your A/C setup?

 

[MANUCHAO]

I run the Mark VIII Electric Fan and was in Zion last weekend on my one month long trip.
Temps from Zion to Barstow were in the 106F.
Needless to say there are a few hills on the way and for the most part my temps were on the 205F-213F.
It did hit 220F on the big hill coming into the state of CA.
But it did not go past that....

I run a Delta FK60 current control for my fan and couldn't be happier with it.....
Oh and I did have to shut my AC on the big hills...

Hope any of this helps....
Good luck

 

[TemboTusk]

how are you controlling the cycling of the compressor on your A/C setup?

The A/C electrics is hooked up into my stock wiring. It is controlled just the same as the original Toyota A/C. No issue whats so ever. The A/C freon lines needed to have the Toyota ends replaced with GM connections. Everything other than the compressor remained the same.


One other thing to keep in mind; be sure your tachometer is hooked up and operating properly through the stock wiring. If the tach is not running, the A/C will not operate properly. It took me a long time to track that one down! The tach would work intermittently due to a loose connection and the A/C clutch would disengage whenever the tack was not working. Finding that solution involved some very deep searching of the MUD files!

 

[TemboTusk]

I run the Mark VIII Electric Fan and was in Zion last weekend on my one month long trip.
Temps from Zion to Barstow were in the 106F.
Needless to say there are a few hills on the way and for the most part my temps were on the 205F-213F.
It did hit 220F on the big hill coming into the state of CA.
But it did not go past that....

I run a Delta FK60 current control for my fan and couldn't be happier with it.....
Oh and I did have to shut my AC on the big hills...

Hope any of this helps....
Good luck

My goal is NOT to turn off my A/C on the big hills!! Well, at least not when it is 110 outside!

I was also on these same hills when I discoved my electric fans were not up to the task. Actually, I was going up Interstate 40 out of California. I had been running the wagon all over SoCal for over two years without a hint of a problem. It was only when I took it out on the open road and in very warm temps that things got out of control.

 

[rover67]

don't have anything really to add, but I have been running the contour fans and a stock rad on my 60 with the vortec for over a year now and have been happy with the temps on and off road anywhere. I have not been in the desert much though.

I am about to make the switch to just a mecanical fan (bought the GM fan and clutch) because wometimes the ECU does not turn on the electric fans and mine are starting to act "old" already. I think ive decided they are not reliable enough. I've praised the setup many times before but am starting to think that a mechanical setup with a good shroud will outpreform what I have now.

If I were you I'd take off the contour fans if you have a mechanical, sine the contour fan and shroud setup tends to block a lot of airflow at higher speeds.

don't knwo if it really helps you out or not but it is what i'm thinking.

 

[TemboTusk]

don't have anything really to add, but I have been running the contour fans and a stock rad on my 60 with the vortec for over a year now and have been happy with the temps on and off road anywhere. I have not been in the desert much though.

I am about to make the switch to just a mecanical fan (bought the GM fan and clutch) because wometimes the ECU does not turn on the electric fans and mine are starting to act "old" already. I think ive decided they are not reliable enough. I've praised the setup many times before but am starting to think that a mechanical setup with a good shroud will outpreform what I have now.

If I were you I'd take off the contour fans if you have a mechanical, sine the contour fan and shroud setup tends to block a lot of airflow at higher speeds.

don't knwo if it really helps you out or not but it is what i'm thinking.

As I mention above, I didn’t know I had a problem for two years. The wagon never left the comforts of the flat land. Once I introduced it to the real world, all bets were off. Another issue is the stock Toyota gage; it is a bit deceptive. I now rely on a numbered gage.

As a temperature reference for the stock gage:
1/4 = 180 degrees
1/2 = 220 degrees
3/4 = 240 degrees

I double checked both the stock gage and the numbered gage with an infrared temp gun on the thermostat housing.

It is too bad about the Contour fans as I also really liked them. It modernized the front of the engine. I hate seeing that big GM fan and makes working the front of the engine that much harder. But, a properly cooled engine is way more important!

 

[MANUCHAO]

Re: Gauge. Mine is the same....
I dont know if your engine runs an OBD II or OBD I, but I also run a scan gauge and it gives me acurate readings from the PCM on Water, Air Intake and Tranny temps... and a whole bunch more...

I thought of pushing my rad a couple of inches closer to the engine and installing an additional electric fan not nessesarily for my water temps but for the tranny temps.......

Im also thinking of running an Oil cooler to help with engine temps...

I dont know how much gear you were hauling with yah..but I know I was really heavy with tons of climbing gear, roof top tent bike rack and two mtn bikes and other winter camping gear, two jerry fuel gas cans and I have a 4+ rear bumper, ice chest with food, two spare tires 33's, extra parts and tools in case I broke down in the middle of no where, probably about 1,000 to 1200 lbs of gear.

I think if I had been lighter I would of been ok....
I have also ran this same route towards St George with a trailer at night and my temps have never gone past the 198F.

 

[MANUCHAO]

I am about to make the switch to just a mecanical fan (bought the GM fan and clutch) because wometimes the ECU does not turn on the electric fans and mine are starting to act "old" already.

You might want to try running a Delta current Control independent from the ECU...

 

[ntsqd]

I just searched my saved threads and didn't find it, but there is a thread around here on how a guy built a fiberglass shroud. The technique looked fairly simple, reasonably fast, and probably messy like any 'glass project. I believe he did it for his GM diesel swap, so that may help in finding the thread.

 

[Mace]

Your mechanical fan is absolutely wothless in the setup you currently have.


I am curious to know where you got your radiator tho..

Stock dimensions?

 

[snowakii]

The mechanical fan really does need a shroud to work properly. If the mechanical fan is helping ... as it sounds like it is.. I wouldn't worry about the restriction of the electrics. Put a shroud on the mechanical fan and you should see a big improvement. As it is without the shroud there is a huge amount of air just swirling about the fan.

Steve

 

[TemboTusk]

Your mechanical fan is absolutely wothless in the setup you currently have.


I am curious to know where you got your radiator tho..

Stock dimensions?

It is not completely worthless, but I can't imagine it is optimal especially in extreme temps. Since I installed the mechanical fan, I am seeing a 20 degree difference in temps with similar road and ambient temp conditions. But, that does not mean much with the outside temps being 79 degrees with a sea breeze! I will be removing the electric fans tonight and installing my stock shroud. Than I will start looking for Vegas like outside temps.

The radiator company I used is called Mattson’s Radiator ( http://www.mattsonsradiator.com )located in the City of Stanton in Orange County. They used the original mounting hardware and built the radiator around that. It bolts right in, other than the top tank, it looks original. Demensions are the same; width, height and thickness.

 

[Mace]

It is not completely worthless, but I can't imagine it is optimal especially in extreme temps. Since I installed the mechanical fan, I am seeing a 20 degree difference in temps with similar road and ambient temp conditions. But, that does not mean much with the outside temps being 79 degrees with a sea breeze! I will be removing the electric fans tonight and installing my stock shroud. Than I will start looking for Vegas like outside temps.

The radiator company I used is called Mattson’s Radiator ( http://www.mattsonsradiator.com )located in the City of Stanton in Orange County. They used the original mounting hardware and built the radiator around that. It bolts right in, other than the top tank, it looks original. Demensions are the same; width, height and thickness.

It's pretty much worthless...
You really used to hit 240* without the mechanical fan?

BTW, at speed, the fans are not doing anything really anyway..

How much crap is in front of the radiator?

Is the radiator Aluminum? If you were replacing the stock radiator with a new one, why would you use the exact same size radiator as the stock one?

I like the idea about putting a shroud on your radiator and trying it. But honestly, I believe your radiator does not have enough cooling capacity for your motor..

 

[rover67]

the contour fans and shrouds block a lot of airflow when not running. That's why i'm going to ditch them when I go mehanical. If I were you I'd remove them and build a nice shroud for it.

I've driven my truck in some pretty hot temps in non flat lands pulling some pretty decent loads and the setup keeps up on the cooling for me. You may be pushing more HP...

I'd go with a nice fan controller, but when one of the contour fan motors fell out of the shroud on a run(bolts holding it came loose) I got pretty frustrated. gonna try mechanical.

I personally think that a shroud for that big GM fan (and running or not running fan) is going to flow a lot more air at hwy speeds than the contour setup, but as has been said you may simply not have enough cooling capacity for your motor in those conditions.