Viscous vs Elec fan

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B

Brendan

Guest
Hello i was wondering does anyone know about these things, i want ot swap my
visous for an electric fan i have been offered.
it is a fan from a jag with which is 13"Dia is this sufficient or not

Cheers Bren

RRC 3.5


 

Brendan wrote:
> Hello i was wondering does anyone know about these things, i want ot swap my
> visous for an electric fan i have been offered.
> it is a fan from a jag with which is 13"Dia is this sufficient or not
>
> Cheers Bren
>
> RRC 3.5


There was a thread on this recently. ISTR that the view was, if it's
working why replace it? There is very little additional benefit from an
electric fan.

Cheers

Peter

110 CSW "Reggie the Veggie"
A40 Farina
Rover P4 110
Hillman Imp

 

"puffernutter" <[email protected]> wrote in message
news:[email protected]...
>
> Brendan wrote:
>> Hello i was wondering does anyone know about these things, i want ot swap
>> my
>> visous for an electric fan i have been offered.
>> it is a fan from a jag with which is 13"Dia is this sufficient or not
>>
>> Cheers Bren
>>
>> RRC 3.5

>
> There was a thread on this recently. ISTR that the view was, if it's
> working why replace it? There is very little additional benefit from an
> electric fan.


Do a search for recent articles, this has been discussed at length on
various occasions. My personal opinion as an engine builder is that
electrical fans promote thermal instability (constant cycling) within the
cooling system, something definitely to be avoided with a V8, more so with
the 3.9 and larger due to block issues, and are next to useless compared to
a properly working viscous setup. The fuel savings are so immeasurable as to
be non-existant.
1. A viscous fan only draws power from the engine when it is required to
lock up and cool. At other times, it consumes virtually no energy.
2. It is a direct mechanical drive with very little energy loss, only a
miniscule ammount is lost to heat.
3. An electric fan has at least 2 energy conversions, mechanical to electric
to mechanical, with heat losses at each conversion stage.
4. The electric is less reliable, I know of more motor failures than viscous
coupling failures.
Just my tuppenceworth.
Badger.


 
On or around Tue, 29 Nov 2005 13:10:12 +0000 (UTC), "Badger"
<[email protected]> enlightened us thusly:

>Do a search for recent articles, this has been discussed at length on
>various occasions. My personal opinion as an engine builder is that
>electrical fans promote thermal instability (constant cycling) within the
>cooling system, something definitely to be avoided with a V8, more so with
>the 3.9 and larger due to block issues, and are next to useless compared to
>a properly working viscous setup. The fuel savings are so immeasurable as to
>be non-existant.
>1. A viscous fan only draws power from the engine when it is required to
>lock up and cool. At other times, it consumes virtually no energy.
>2. It is a direct mechanical drive with very little energy loss, only a
>miniscule ammount is lost to heat.
>3. An electric fan has at least 2 energy conversions, mechanical to electric
>to mechanical, with heat losses at each conversion stage.
>4. The electric is less reliable, I know of more motor failures than viscous
>coupling failures.
>Just my tuppenceworth.


I'll add my pennorth here an' all.

on the 110, when I put the original V8 in, it was a P5B engine with a
well-bent fan, and since I had a leccy fan anyway, I kept it. One hot day
the leccy fan motor gave up and siezed.

after that, I looked around in the shed and found a fixed fan to bolt on the
engine. Very littel to go wrong, and the only thing it does is waste a
small amount of power spinning when it doesn't need to.

Viscous fan should psin for the first 30 sec or so, (you will hear it at
moderate revs) and then spin down to idle unless it gets too hot. Provided
it works, it's very effcetive, and they seem to fail most often into "stuck
on" mode, which is a bit noisier and less efficient but at least doesn't
overheat the engine.

--
Austin Shackles. www.ddol-las.net my opinions are just that
Blue: The sky is blue for a reason. Blue light is a source of strength
and harmony in the cosmos. Create a blue light in your life by
telephoning the police
from the Little Book of Complete B***ocks by Alistair Beaton.
 
In message <[email protected]>
"Badger" <[email protected]> wrote:

>
> "puffernutter" <[email protected]> wrote in message
> news:[email protected]...
> >
> > Brendan wrote:
> >> Hello i was wondering does anyone know about these things, i want ot swap
> >> my
> >> visous for an electric fan i have been offered.
> >> it is a fan from a jag with which is 13"Dia is this sufficient or not
> >>
> >> Cheers Bren
> >>
> >> RRC 3.5

> >
> > There was a thread on this recently. ISTR that the view was, if it's
> > working why replace it? There is very little additional benefit from an
> > electric fan.

>
> Do a search for recent articles, this has been discussed at length on
> various occasions. My personal opinion as an engine builder is that
> electrical fans promote thermal instability (constant cycling) within the
> cooling system, something definitely to be avoided with a V8, more so with
> the 3.9 and larger due to block issues, and are next to useless compared to
> a properly working viscous setup. The fuel savings are so immeasurable as to
> be non-existant.
> 1. A viscous fan only draws power from the engine when it is required to
> lock up and cool. At other times, it consumes virtually no energy.
> 2. It is a direct mechanical drive with very little energy loss, only a
> miniscule ammount is lost to heat.
> 3. An electric fan has at least 2 energy conversions, mechanical to electric
> to mechanical, with heat losses at each conversion stage.
> 4. The electric is less reliable, I know of more motor failures than viscous
> coupling failures.
> Just my tuppenceworth.
> Badger.
>
>


I agree with all the above, plus the 3.9 on V8's have some *really*
scary temperatures in the spark plug "holes", which an electric fan
will not cool when not running, leading to spark plug & lead problems.
(Source - project at Rists (lead makers) when working there)

Richard

--
www.beamends-lrspares.co.uk [email protected]
Running a business in a Microsoft free environment - it can be done
Powered by Risc-OS - you won't get a virus from us!!
Boycott the Yorkshire Dales - No Play, No Pay
 
puffernutter <[email protected]> uttered summat worrerz funny
about:
> There was a thread on this recently. ISTR that the view was, if it's
> working why replace it? There is very little additional benefit from
> an electric fan.
>
> Cheers
>
> Peter


Yup I found no difference, Just quieter running. Other than that a waste of
my time.

Lee D



 
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