Is the mech/elec fan debate settled?

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Joined
Oct 14, 2007
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Location
Lufkin, Texas
After I get my new carpet installed, I'm planning on sorta doing a total retro of the front of my engine. I want to pull the radiator, have it boiled out and repainted (seems to be in good shape) and while its off, I'm gonna pull all the A/C gear and replace everything, new dryer, and rebuilt compressor, and probably put in a new alternator while I've got it easy to access. Looks like some of the hardware on the alt adjustment is on its last leg. Bought a new idler pully for the a/c belt. I may go ahead and replace the water pump because I don't have any clue how many miles it has on it. Depends on how bad that will set me back, and then when I get it all back together, I'm installing the transmission cooler I just bought. Still, I pulled 6,000 lbs of rock the other day in 100 degree heat and it never ran hot.

After this, I'm moving to the front axle rebuild with the 4 runner brake upgrade.

My question is should I removed the mechanical fan and replace with one of the electric fan set ups. I know there's been a lot of debate on that. I don't have any problems leaving the mechanical fan in because I don't put a lot of miles on this vehicle. Maybe 3000 a year. I'm leaning toward leaving the mechanical fan in there. However, I'm here in Texas and its pretty hot here all year round.

Just wondering what everybody thinks.
 
if its not broken, don't mess with it! :)

i think Either the Taurus Fan Wired Properly with a good Alternator and Battery, Or a Nice Mechanical Fan will pull similar amount of air, its a matter of preference.
 
IF you have a good radiator and fan clutch works like it should, the stock mechanical fan performs very nice for the I-6 engine. When I had the I-6 in my truck I ran anywhere and everywhere and with the A/C on....off-road and on. Never any over-heating problems. Plus you need the fan shroud to be fully functional.
 
stay mechanical.
 
FWIW...Im leaning toward an electric fan for when I do my V8 swap. The reason for this is so Ill have greater engine positioning capeabilities and I also plan on installing a "back up" manual switch in the event of the auto temp sensor failure. Seems like good sense TO ME...
If the mechanical fan fails, it seems youre pretty screwed. Am I right?

Chicago
 
v-8 engine swap is a different story. You will have to pay careful attention to the positioning of the engine relative to the radiator if you plan to use a mechanical fan. Some of the adapters put the engine fairly close to the radiator (marks adapter) to keep the drivetrain in the stock position. I have the dual electric contour fan on my V-8 swap and I think it does a good job. Given the distance between the water pump and radiator core on my swap I think it would almost be impossible to run a mechanical fan, unless you want to run one of those Flex fans, which I do not.

Same difference if any fan fails you are screwed. Generally speaking mechanical fans do not fail, and when there are problems its the fan clutch most of the time.

Electric fans are very tough and have few failures...most of the times the failure is not the actual fan electric motor but the controller or relay that controls the fans. I have a Honda Accord with over 200K miles with original OEM dual electric fans.

If you can run the stock GM fan clutch and fan, then I would say do so....if you can't then resort to what I and others have done on the V-8 Swap...run the Dual contour fan setup, or the Mark VIII fan. My SPAL Controller gave up the ghost and I went with a dual relay setup from SPAL and a single sensor in the cylinder head that turns the fans on and off. The newer PCM / for GM V-8's can controal the electric fans. THe SPAL setup I have grounds the control wire for the relays to turn the fans on. SO you could install a toggle in line to turn the fans on or disable them in the case of a water crossing. I don't know if you can do the same with a PCM controlled radiator electric fan.

The dual for contour fans are nicely configured and cover the rear of the LC radiator very good. I will try to get my A/C running by end of the summer and we'll see how they function then.

My comments apply to the 5.7 swap... I don't know if the same issues apply to the 4.8, 5.3, and 6.0 GM V-8 swaps.
 
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Being in the Chevota business, I deal with this every minute of my life. I've been giving the same advice for 38 years now, and nothing has made that advice change to date.
(a) The only problem I have with electric fans is that normally the only ones with high enough cfm to cool your rig are too big and won't fit inside your engine compartment. Consequently guys run 2,000 to 3,000 cfm when they actually need 4,000 cfm.
(b) There is nothing I like, or ever will like about flex fans!!!!
(c) I like big bad-ass, chain saw massacre, engine driven air conditioning fan blades that have the torque of the engine behind them. You need a gosh darn hurricane to blow out your engine compartment oven, and nothing is going to do that better than an engine driven fan!!!!!
Now, new subject---DO NOT put any portion of a fan blade up inside a fan shroud. That's the number one problem I see every day. If you need, or run a fan shroud, make it end at the front edge of your fan blade!!!!!
 
Being in the Chevota business, I deal with this every minute of my life. I've been giving the same advice for 38 years now, and nothing has made that advice change to date.
(a) The only problem I have with electric fans is that normally the only ones with high enough cfm to cool your rig are too big and won't fit inside your engine compartment. Consequently guys run 2,000 to 3,000 cfm when they actually need 4,000 cfm.
(b) There is nothing I like, or ever will like about flex fans!!!!
(c) I like big bad-ass, chain saw massacre, engine driven air conditioning fan blades that have the torque of the engine behind them. You need a gosh darn hurricane to blow out your engine compartment oven, and nothing is going to do that better than an engine driven fan!!!!!
Now, new subject---DO NOT put any portion of a fan blade up inside a fan shroud. That's the number one problem I see every day. If you need, or run a fan shroud, make it end at the front edge of your fan blade!!!!!

Amen to that! And, for what it's worth, the Marks Bellhousing adapter leaves plenty of room for fan options, at least in a 60. I ran a big Chevy fan on a clutch without any shroud at all and I never had any problems. About that fan-in-the-shroud thing, my Bimmer has the fan OUTSIDE the shroud.
 
If the mechanical fan fails, it seems youre pretty screwed. Am I right?

If your fan clutch fails you can open it up and pack it with dirt/sand to lock it up 100% and you're back on the road (tip credit goes to MarkW). If the belt fails, well, your water pump won't turn so you'll be screwed with either a mechanical or an electric. If your crank pulley bolt unscrews and destroys your fan blade you definitely are screwed (ask me how I know :hillbilly:). Generally speaking though you'll be more reliable with a mechnical fan as there is less to fail.

That being said I now run an electric Ford Contour, DCC variable speed controller and a high output alt with my 3FE and I am happy with the conversion.
 
all very good and insightful points to consider!
Personally, I want the most reliable when Im in the middle of no where and if it requires me having to fab a new cross member t do it...I rather take the extra time.

Sorry I really didnt intend to hijack this thread, but this is good info here!

Highjack over!

Chicago
 
I have a davies craig electric fan and thermo switch on my rig. Have always disliked mechanical fans since one winter i ran my worked datsun with no fans at all and the extra power actually shocked me.
Since then I have always figured the mechanical fan saps a bunch of power/fuel but it isn't as noticable on the low revving 3f.
I have plans to rig up a warning light from the thermo switch to warn me if the temp gets too high and im not paying attention.
I haven't wheeled much since the instal but have left the thing idling in the drive for 45 minutes and the temp stayed where i set it.
 
Since then I have always figured the mechanical fan saps a bunch of power/fuel but it isn't as noticable on the low revving 3f.
.

The whole idea of the clutch fan is that it only works when you need it. Electric fans use up electricity and make your alternator work harder ,which is also a load on the engine.
No such thing as a free lunch.
 
Except that the electric is only a draw when it is on. Under normal operation it is off more than it is on.

I like my electric but I would stick with your mechanical. The underhood temps can climb quite high even though the engine temp is acceptable. The mechanical moves air though the engine bay even when the clutch is disengaged.
 
while its true there is no "free lunch", electrical load of this type is not much of a factor. Its not really one or othe other in terms of loss of power. The smaller the engine the more noticeable the drain of power from like fan clutch engaging or the A/C turning on, because there is less power to go around.

Engine driven radiator fans with fan clutches have been around a long time and are pretty much bullet proof for the most part. Electrical fans for automotve use have really been mainstream since the 80's.

The real advantage of an electircal fan setup is that it runs at 100% when its on (for the most part, given how you power it). Electrical fans are especially good at cooling at slow speeds and idle conditions (which you see off-road). Fan clutch setups are not so efficient at idle and low speed, but do pull more air across the radiator (generally speaking) at higher engine RPM than do electric fans. So if you run electric fans its important to get one or dual fans that are appropriate for the job....ie have the power to properly cool the vehicle in question and you have the proper wiring and correct ALT to power them.

That being said... the OEM cooling setup on the LC is very good and does a good job in all around conditions. If you swap a V-8 in there and can adapt the GM fan clutch setup then you will be good.

I think the biggest limitation on the LC V-8 Swap cooling is the surface area of the radiator you can use in the stock location (FJ 60). Given that.... some of the guys here have proven that the dual ford contur fans , and the Mark VIII type fan works. Of course the GM fan clutch setup off a SUV or pickup that came with a V-8 will work fine as adapted to the LC.

Regardless of what others may say.... the fan shroud is critical. Look at any OEM cooling solution with a mechanical radiator fan.... the vehicle has a radiator shroud. Also notice on most OEM electrical radiator fans....they cover the rear of the radiator (most setups) and generally they have a shroud or the mount in which the fans are installed, is a shroud itself. "Directed Air Flow" You can have a fan with extreme pitch on the blades and it can grab all the air under the hood....but if its not directed across and the through the radiator...then its not going to be efficient as it can be. Sure people have vehciles with all kinds of setups...does not mean its working efficiently.
 
I know that this is not at the heart of the debate, but I was wondering what the sound level is of the electric fans vs the mechanical ones? There have been several threads from new folks, including myself at one time, who "hear" the clutch fan kick on and off. It used to bother me but now it is less noticeable. Do the electrics make noise that can be heard at highway speed?
 
My Ford Contour fan isn't any louder than my stock fan. Not sure that it is any quieter either though. I don't hear it at highway speeds but that is going to vary from rig to rig (tires...).
 
Well, my overall goal for this vehicle is to restore it to original condition, aside from a few upgrades. It will not be used for crawling or anything like that, maybe occasionally towing the sailboat, and little chance I'll be stuck in traffic anywhere with it, so I think I'll stay with the stock mechanical fan setup. I really appreciate the info.
 
so far this winter my elec fan has not come on at all.

noise wise at idle with no radio on and the interior fan on 1 i can hear the leccy fan, as soon as im moving the air/tyre noise wil drown it out or the interior fan on 2 will drown it out.
 
No fan clutch

Been reading the debate .... i have an 85 62 that comes without a clutch .... this thing is directly connected to the engine.... i tried a single fan electric which actually turned out to give Noticeably more power but heated up within 2 hours into my wheeling trip so now im back to mechanical.

I might give the contour ones a go just to regain the power feeling again....
just my 2cents ....
 

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