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flex fan
https://slantsix.org/forum/viewtopic.php?t=13463		 Page 3 of 3
Author:  edwinjmartz [ Tue Aug 09, 2005 6:43 pm ]
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SlantSixDan, I did say I'd mounted my fan in front of the radiator. There is a lot of room behind the grill. Plus, too, when you remove the belt-driven fan and spacer, you get even more room. I can even change my water pump with-out removing the radiator.
I don't believe an upgrade would be necessary for the alternator as long as idle speed is properly set. My other car is a Subaru that has a 55 amp alt and runs 2 stock electric fans.
Author:  steponmebbbboom [ Wed Aug 10, 2005 7:11 pm ]
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Look at how much more efficient the hybrid cars are compared to their straight-petrol counterparts, even though the hybrids run an engine to spin a generator to charge batteries to run a motor. Look at diesel-electric locomotives, configured that way (diesel engine runs a generator charges batteries run traction motors) because it's more efficient.
I believe the gain in efficiency in a hybrid is mostly due to a) true regenerative braking i.e. the gennie acts as a brake and recovers energy rather than dissipating it as heat and b) the ability to run the engine at constant-load, constant-speed conditions, allowing you to optimise the engine to take advantage of this (IIRC the first-gen Prius had variable valve timing among other things, it's in my NCF manual for the car which is tucked away somewhere.)

Really too bad that the Honda engineers decided to approach their latest hybrid designs as a "free turbo" to pander to the selfish pricks who want to "go green" but don't want to sacrifice one little bit of unnecessary acceleration and throttle response. Let's make the car go faster with the same gas mileage.

Disgusting.

As far as diesel-electric locomotives, no, this setup isnt the most theoretically efficient, it is the huge amount of starting torque required to get a 95+ car consist in motion that necessitates the use of electric motors. Actually, locomotives waste a huge amount of energy during retard braking, whereby the traction motors are used to brake the consist, but having no battery bank to store the energy in, this power is just pissed away by means of the huge resistors mounted at the sides of the carbody near the top. On the SD40s they appear as torpedo-like bulges with grilles in them. You could drag two or three battery cars behind you to recoup this energy I suppose, but maintenance of these batteries would be a nightmare, and diesel even now is far cheaper to waste this way than recover. Maybe it will happen. All I know is this continent has a rail system that Bulgaria would be ashamed of, and we are going to wish we had a good one when oil hits $200/b.
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True, but the fan's still turning (and taking energy) when it's not needed, which eats into system efficiency.
I wonder how much? There is some drag on the fan clutch when it's declutched, but very little. True it is more than the zero extra drag from the electric fan when it's off, but that alternator locks up pretty good when the fan's on. Itd be interesting to do a lab study on this. Maybe someone already has? Google anyone?
Author:  caveman [ Thu Jan 05, 2006 10:55 am ]
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I did an experiment recently with an electric fan and my A100 van: I have a flexalite "S" bladed fan which pushes something like 5200 cfm. I mounted it to the front of the radiator and set the blades to be a "pusher" since the clearance between my 4 row radiator and the water pump pully is minimal. The results were HOTTER than the stock four blade fan i'd removed. The temp guage climbed until i shut off the motor after passing the 230 mark.

It seems when mounting an electric fan, the "puller" method is important (at least in a van with that toaster oven doghouse) as it creates a simple air current blowing over the motor and exhaust which cools it down as well as drawing air through the radiator.

Unfortunately the slant six doesn't leave much room for this in a van.
Author:  caveman [ Thu Jan 05, 2006 10:55 am ]
Post subject: 
I did an experiment recently with an electric fan and my A100 van: I have a flexalite "S" bladed fan which pushes something like 5200 cfm. I mounted it to the front of the radiator and set the blades to be a "pusher" since the clearance between my 4 row radiator and the water pump pully is minimal. The results were HOTTER than the stock four blade fan i'd removed. The temp guage climbed until i shut off the motor after passing the 230 mark.

It seems when mounting an electric fan, the "puller" method is important (at least in a van with that toaster oven doghouse) as it creates a simple air current blowing over the motor and exhaust which cools it down as well as drawing air through the radiator.

Unfortunately the slant six doesn't leave much room for this in a van.
Author:  SlantSixDan [ Thu Jan 05, 2006 3:01 pm ]
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It seems when mounting an electric fan, the "puller" method is important
Yep, pullers definitely work better than pushers. With a pusher, you've got the fan structure/motor itself blocking/disrupting airflow through the radiator core. With a puller, the physical obstruction is downstream of the radiator core. That is, the air has already passed over the heat exchanger before it runs into the physical obstruction.
Author:  ramcharged [ Thu Jan 05, 2006 3:19 pm ]
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All I can say is stay away from rivit constuction flex fans.a good freind of mine almost died when he revved the motor and one of the blades let go into his neck.not good. Besides they are not very effective as an improvement.my preference always goes to clutch fans(or electric if you can fit & afford it,good ones have curved blades & thermostatic controls,easly set u back $200-300.00)A quick way to check a fan clutch is with engine idling put a piece of heater hose into the blades,if the fan stops the clutch is bad, if it does't the clutch is good and you can look elseware for problems.Just my 2-cents for what it's worth.

Ted
Author:  SlantSixDan [ Thu Jan 05, 2006 3:42 pm ]
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All I can say is stay away from rivit constuction flex fans.a good freind of mine almost died when he revved the motor and one of the blades let go into his neck.not good.
Definitely, flex fans have a spotty safety record at best, for exactly the reason you describe. It may interest some here to know who made the infamous fly-apart-and-kill-bystanders Ford flex fans of the 1970s: Fram! :shock:
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A quick way to check a fan clutch is with engine idling put a piece of heater hose into the blades,if the fan stops the clutch is bad, if it does't the clutch is good
H'mm. I don't like this test. It would not really check the fan clutch for proper operation, because whether or not the fan would stop depends on the position of the control valve, which in turn depends on the draw-through air temperature coming off the radiator. Also, some fan blades used with clutches are made out of aluminum, and these could easily be spoiled (bent) by putting a chunk of heater hose into the spinning fan. Finally and not least, this is a very dangerous thing to do. Deliberately chucking a foreign object into the path of a fast-moving fan blade is asking for several different kinds of unpleasant and sudden things to happen.
Author:  ramcharged [ Thu Jan 05, 2006 4:00 pm ]
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that method of checking a fan clutch has never steered me wrong or hurt me or anyone else.BTW you don't throw the hose in the fan, you hold it.I actually learned that method at B.C.I.T. which if it was dangerous or could damage parts I don't think it would be taught.please try this if you don't trust or believe me.Use a known good clutch and a known bad clutch.Then let me know if this is cheaper and easier than replacing a approx.$60.00up clutch to find out that it's not the problem.Again just my 2-cents.
Ted
Author:  SlantSixDan [ Thu Jan 05, 2006 4:44 pm ]
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that method of checking a fan clutch has never steered me wrong or hurt me or anyone else
If it's worked well for you, and you've avoided injury, that's great. But with all due respect, you have no way of knowing that it's never hurt anyone else.
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you don't throw the hose in the fan, you hold it.
Even less safe than throwing a foreign object into a spinning fan is placing a foreign object into the path of a spinning fan while you're still holding onto it. It's just not a wise idea, from where I sit.
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I actually learned that method at B.C.I.T. which if it was dangerous or could damage parts I don't think it would be taught.
Over the years, I've had a lot of teachers teach me a lot of things. Some of those things were good and correct and useful. Other times, the teacher's full of poo.
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please try this
No.
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if you don't trust or believe me.Use a known good clutch and a known bad clutch.
It's not that I disbelieve you—as far as I know, you have no reason to lie; you're just sharing your experience and what you've been taught. The thing is, fan clutches can fail in two different ways (fan drives when it should spin freely, fan spins freely when it should drive), and with a properly-operating clutch the fan may be under drive or mostly free-spinning at idle, which means the results of this heater hose test can't indicate anything about the health of the clutch.
Author:  sandy in BC [ Thu Jan 05, 2006 8:48 pm ]
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Now we know why I run with no fan,,,,,and keep my pants zipped up........
Author:  68barracuda [ Mon Aug 11, 2008 10:16 pm ]
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OK hear me out

First of all sticking anything in a spinning fan is bad OK- over here in RSA it is a guaranteed method of getting your dingle berries removed by the management - ie the wife, the boss etc.

What worries me about this method is the way the fan reacts to this.

You stop the fan - relatively to the fan the clutch is now running faster - bigger rpm difference, centrifugal clutch disengage. Cool

Now due to internal fiction the coupling fluid heats up and gels and get the fan spinning or tries to.....

Get the picture.

Just wondering
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