[s-cars] Viscous fan clutch failure?

Fri May 11 20:37:20 EDT 2007

yes, there's some parasitic drag from the mechanical fan.  the advantage
of the electric fan is that it operates on-demand, and when the car is
moving, it will likely not be running because there will be enough airflow
through the radiator.

replacing the mechanical fan with an electric fan is probably worth a
few hp - if the electric fan isn't running.

i replaced the mechanical fan on my mustang with an electric fan, but
primarily for reliability reasons.  the mechanical fan was driven off
the water pump on my 5.0, and in heavy track use, that tends to kill
water pump bearings because of all the weight hanging out there.
that's not an issue with our cars, so i would be inclined to keep
the current mechanical fan setup unless you're having trouble finding
a replacement viscous clutch.

if you do decide to install an electric fan, make sure you use an OEM
fan.  i would not trust the aftermarket electric fans.  they aren't
built to last.  the construction is cheaper - thinner wires, low quality
bearings.  i'd rather go to the junkyard and look for a fan from a
FWD car with a V6 or V8.  they tend to be very crowded in the engine
compartment, requiring a thinner fan with more power to keep them cool.

-teddy

--- Mark Strangways <StrangConst at rogers.com> wrote:

> Not really a free ride. It does steal HP
> Maybe like you said an electric clutch that would dump it under high rpm / 
> high load usage.
> After all who needs a fan at 150 MPH
> 
> Mark
> ----- Original Message ----- 
> From: <djdawson2 at aol.com>
> To: <StrangConst at rogers.com>; <josh at spiny.com>; <S-CAR-List at audifans.com>
> Sent: Friday, May 11, 2007 7:24 PM
> Subject: Re: [s-cars] Viscous fan clutch failure?
> 
> 
> >I don't think there's anything "wrong" with electric fans... it's just that 
> >they tend to use rather high current motors.  That mean relays and 
> >switches... and increased alternator load.  An engine driven fan is 
> >essentially a "free ride" so it makes more sense to me... when it's an 
> >option.  Some engine compartments just don't have the space.
> >
> > Dave
> >
> >
> > -----Original Message-----
> > From: StrangConst at rogers.com
> > To: josh at spiny.com; S-CAR-List at audifans.com; djdawson2 at aol.com
> > Sent: Fri, 11 May 2007 5:21 PM
> > Subject: Re: [s-cars] Viscous fan clutch failure?
> >
> >
> > What's wrong with electric fans.
> > I guess other than the weight of the motor.
> >
> > I just saw Audi Canada's wrecked (at Mosport) 2007 S8 V10 (5.2 l) it has 
> > one electric fan left...
> > Gonna see how it will fit.
> > Anyone want an S8 interior, or motor ? What is left of the car is all for 
> > sale
> >
> > Mark
> > ----- Original Message ----- 
> > From: djdawson2 at aol.com
> > To: josh at spiny.com ; StrangConst at rogers.com ; S-CAR-List at audifans.com
> > Sent: Friday, May 11, 2007 7:06 PM
> > Subject: Re: [s-cars] Viscous fan clutch failure?
> >
> >
> > Still yet, the best solution is the fan clutch that is activated much like 
> > the A/C clutch.  No engagement at all when not required, and then full 
> > engagement when needed.
> >
> > Haven't seen that on cars yet.
> >
> >
> > -----Original Message-----
> > From: josh at spiny.com
> > To: StrangConst at rogers.com; S-CAR-List at audifans.com
> > Sent: Fri, 11 May 2007 4:33 PM
> > Subject: Re: [s-cars] Viscous fan clutch failure?
> >
> >
> > Mark, that might be true on old cars without modern fan clutches, but
> > the clutch is there to keep the fan from robbing too much power, and
> > also to keep the noise down.  The idea is that the hotter the air
> > gets around the fan, the more air it moves.  Plus, a viscous clutched
> > fan is able to move much more air than an electric fan, and more
> > reliably too. They're not without their problems, but they do have
> > some important advantages over electric fans.
> >
> > On May 11, 2007, at 8:36 AM, Mark Strangways wrote:
> >
> >> Yank that sucka outta there and put in an electric.
> >> Good for about 30-50 HP... Dyno proven
> >>
> >> Mark
> >> ----- Original Message -----
> >> From: "Peter Golledge" <petergolledge at gmail.com>
> >> To: <s-car-list at audifans.com>
> >> Sent: Friday, May 11, 2007 9:05 AM
> >> Subject: [s-cars] Viscous fan clutch failure?
> >>
> >>
> >>> Folk,
> >>>
> >>> My wife reported some unusual noise from her 95 S6 and no A/C.  I
> >>> check
> >>> out
> >>> the car last night... everything seems fine.  Get it up to
> >>> operating temp
> >>> with a drive, still no problems.  Looking at the primary fan I see it
> >>> turning maybe 60 rpm with the engine idling.  Stops with the touch
> >>> of bit
> >>> of
> >>> plastic scrap.  No huge play in the clutch but I suspect its
> >>> dead.    Any
> >>> BTDT on the list?
> >>>
> >>> With the fan blades off I can easily get a big 32" spanner on the
> >>> clutch.
> >>> Anyone removed it by holding the pulley with rubber filter strap or
> >>> similar?
> >>>
> >>> Regards
> >>> -- 
> >>> Peter Golledge
> >>>
> >>> 95 S6, 89 200TQA, 87 LT-1Q, 1979 930
> >>> _______________________________________________
> >>> S-CAR-List mailing list
> >>> S-CAR-List at audifans.com
> >>> http://www.audifans.com/mailman/listinfo/s-car-list
> >>>
> >>
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