Earle Horton

This post is incoherent to the point of surrealism.

Unless you use a 120 volt overnight block heater, there is no such thing as
"instant" heat, and there is no "viscous heater".

Saludos cordiales,

Earle

"stilllearning" <shahswim@yahoo.com> wrote in message
news:1181746281.704135.6060@q19g2000prn.googlegrou ps.com...
> Where exactly is the viscous heater clutch located? Is it part of the
> A/C clutch?
>
> Where exactly is the viscous heater?
>
> Trying to understand passenger cabin heating:
>
> Normally the coolant heats the cabin, but that happens only after the
> coolant heats up (maybe a few minutes after a engine start) and the
> thermostat opens up to send fluid to the radiator.
>
> The viscous heater heats the cabin immediately after engine start and
> until the coolant is hot.
>
> Why then, in cold weather, if the heater **** is set to high, the
> cabin is heated only after a few minutes? Shouldn't the viscous heater
> heat the cabin immediately?
>



--
Posted via a free Usenet account from http://www.teranews.com

Earle Horton

This post is incoherent to the point of surrealism.

Unless you use a 120 volt overnight block heater, there is no such thing as
"instant" heat, and there is no "viscous heater".

Saludos cordiales,

Earle

"stilllearning" <shahswim@yahoo.com> wrote in message
news:1181746281.704135.6060@q19g2000prn.googlegrou ps.com...
> Where exactly is the viscous heater clutch located? Is it part of the
> A/C clutch?
>
> Where exactly is the viscous heater?
>
> Trying to understand passenger cabin heating:
>
> Normally the coolant heats the cabin, but that happens only after the
> coolant heats up (maybe a few minutes after a engine start) and the
> thermostat opens up to send fluid to the radiator.
>
> The viscous heater heats the cabin immediately after engine start and
> until the coolant is hot.
>
> Why then, in cold weather, if the heater **** is set to high, the
> cabin is heated only after a few minutes? Shouldn't the viscous heater
> heat the cabin immediately?
>



--
Posted via a free Usenet account from http://www.teranews.com

Earle Horton

This post is incoherent to the point of surrealism.

Unless you use a 120 volt overnight block heater, there is no such thing as
"instant" heat, and there is no "viscous heater".

Saludos cordiales,

Earle

"stilllearning" <shahswim@yahoo.com> wrote in message
news:1181746281.704135.6060@q19g2000prn.googlegrou ps.com...
> Where exactly is the viscous heater clutch located? Is it part of the
> A/C clutch?
>
> Where exactly is the viscous heater?
>
> Trying to understand passenger cabin heating:
>
> Normally the coolant heats the cabin, but that happens only after the
> coolant heats up (maybe a few minutes after a engine start) and the
> thermostat opens up to send fluid to the radiator.
>
> The viscous heater heats the cabin immediately after engine start and
> until the coolant is hot.
>
> Why then, in cold weather, if the heater **** is set to high, the
> cabin is heated only after a few minutes? Shouldn't the viscous heater
> heat the cabin immediately?
>



--
Posted via a free Usenet account from http://www.teranews.com

stilllearning

On Jun 13, 10:52 am, stilllearning <shahs...@yahoo.com> wrote:
> On Jun 13, 10:51 am, stilllearning <shahs...@yahoo.com> wrote:
>
>
>
>
>
> > Where exactly is the viscous heater clutch located? Is it part of the
> > A/C clutch?
>
> > Where exactly is the viscous heater?
>
> > Trying to understand passenger cabin heating:
>
> > Normally the coolant heats the cabin, but that happens only after the
> > coolant heats up (maybe a few minutes after a engine start) and the
> > thermostat opens up to send fluid to the radiator.
>
> > The viscous heater heats the cabin immediately after engine start and
> > until the coolant is hot.
>
> > Why then, in cold weather, if the heater **** is set to high, the
> > cabin is heated only after a few minutes? Shouldn't the viscous heater
> > heat the cabin immediately?
>
> Jeep WJ 2004, I6, 4WD.- Hide quoted text -
>
> - Show quoted text -

Seems the viscous heater is esoteric enough that googling "viscous
heater clutch" returns no entries! More information on the viscous
heater clutch; here are three relevant pages from the factory service
manual:

http://new.photos.yahoo.com/shahswim...60762403547730

stilllearning

On Jun 13, 10:52 am, stilllearning <shahs...@yahoo.com> wrote:
> On Jun 13, 10:51 am, stilllearning <shahs...@yahoo.com> wrote:
>
>
>
>
>
> > Where exactly is the viscous heater clutch located? Is it part of the
> > A/C clutch?
>
> > Where exactly is the viscous heater?
>
> > Trying to understand passenger cabin heating:
>
> > Normally the coolant heats the cabin, but that happens only after the
> > coolant heats up (maybe a few minutes after a engine start) and the
> > thermostat opens up to send fluid to the radiator.
>
> > The viscous heater heats the cabin immediately after engine start and
> > until the coolant is hot.
>
> > Why then, in cold weather, if the heater **** is set to high, the
> > cabin is heated only after a few minutes? Shouldn't the viscous heater
> > heat the cabin immediately?
>
> Jeep WJ 2004, I6, 4WD.- Hide quoted text -
>
> - Show quoted text -

Seems the viscous heater is esoteric enough that googling "viscous
heater clutch" returns no entries! More information on the viscous
heater clutch; here are three relevant pages from the factory service
manual:

http://new.photos.yahoo.com/shahswim...60762403547730

stilllearning

On Jun 13, 10:52 am, stilllearning <shahs...@yahoo.com> wrote:
> On Jun 13, 10:51 am, stilllearning <shahs...@yahoo.com> wrote:
>
>
>
>
>
> > Where exactly is the viscous heater clutch located? Is it part of the
> > A/C clutch?
>
> > Where exactly is the viscous heater?
>
> > Trying to understand passenger cabin heating:
>
> > Normally the coolant heats the cabin, but that happens only after the
> > coolant heats up (maybe a few minutes after a engine start) and the
> > thermostat opens up to send fluid to the radiator.
>
> > The viscous heater heats the cabin immediately after engine start and
> > until the coolant is hot.
>
> > Why then, in cold weather, if the heater **** is set to high, the
> > cabin is heated only after a few minutes? Shouldn't the viscous heater
> > heat the cabin immediately?
>
> Jeep WJ 2004, I6, 4WD.- Hide quoted text -
>
> - Show quoted text -

Seems the viscous heater is esoteric enough that googling "viscous
heater clutch" returns no entries! More information on the viscous
heater clutch; here are three relevant pages from the factory service
manual:

http://new.photos.yahoo.com/shahswim...60762403547730

stilllearning

On Jun 13, 10:52 am, stilllearning <shahs...@yahoo.com> wrote:
> On Jun 13, 10:51 am, stilllearning <shahs...@yahoo.com> wrote:
>
>
>
>
>
> > Where exactly is the viscous heater clutch located? Is it part of the
> > A/C clutch?
>
> > Where exactly is the viscous heater?
>
> > Trying to understand passenger cabin heating:
>
> > Normally the coolant heats the cabin, but that happens only after the
> > coolant heats up (maybe a few minutes after a engine start) and the
> > thermostat opens up to send fluid to the radiator.
>
> > The viscous heater heats the cabin immediately after engine start and
> > until the coolant is hot.
>
> > Why then, in cold weather, if the heater **** is set to high, the
> > cabin is heated only after a few minutes? Shouldn't the viscous heater
> > heat the cabin immediately?
>
> Jeep WJ 2004, I6, 4WD.- Hide quoted text -
>
> - Show quoted text -

Seems the viscous heater is esoteric enough that googling "viscous
heater clutch" returns no entries! More information on the viscous
heater clutch; here are three relevant pages from the factory service
manual:

http://new.photos.yahoo.com/shahswim...60762403547730

SnoMan

On Wed, 13 Jun 2007 11:05:37 -0400, Mike Romain <romainm@sympatico.ca>
wrote:

>The 'viscous' part of the fan is normally the part that causes the
>'radiator' fan to freewheel when the engine is cold and to stiffen up
>almost solid when the engine heats up so it sucks cold air to cool down
>the radiator.

I can see that you really do not know how these work either. It works
on the theory of a silicone fluid between discs that transfer power
via fluid between them due to shearing forces. The fluid is constantly
pumped out of the "disc" area into a reservior so that is can free
wheel, it starts to engage so to speak when the bi metal coil allows
fluid to return to clutch area and when it is returned at a rate that
exceeds the rate at wheich is it removed at it reaches it sate of
least slippage. It is never a solid or even should be described as
one. The fluid used has been choosen because of its shearing
properties (as rate of shear increases, the power to shear it
increases dramatically unlike motor oil) and for very high resistance
to the tempatures generated by this shearing. It is a old and proven
concept. The amount of torque this design can transfer it limited by
the diameter and amount of clutches and the cooling for them because
the shearing can generate a lot of heat. BTW, when fan engages it also
improves A/C efficency and output (if you have one) as it cools the
refrigerant more before it is expanded again which makes it cooler
when it is expanded. When clutch fans first made their appearance in
the 60's, they were mostly on cars with A/C on them and later were
used on basically all cars by early to mid 70's or so A/C or not

>
>This is a 'gas saving' device apparently saving the gas needed to spin
>the fan when the engine is not running hot. The fan does take several
>HP to spin up under load.

Yes it was designed as a gas saving device of sorts and also a way to
allow for increased cooling capacity during times of need and reduce
fan noise when it is is not needed. The only weakness of the design is
too fold, first detriot tends to be conservative with the bi metal
coil setting on some applications lets vehcile get pretty warm some
times and the second is as the mi metal coil ages by nature it will
increase engagement temp and make you think that your clutch fan is
worn out when it may only need a adjustment. As long as the clutch
does not wobble on shaft and fluid has not leaked out it is likely
still good and may at most need a little tweaking to restore its
operation. I have been tweaking them for many many years and if you
want to know how you can find instructions in link below.

http://forum.snoman.com/viewtopic.php?t=79

-----------------
TheSnoMan.com

SnoMan

On Wed, 13 Jun 2007 11:05:37 -0400, Mike Romain <romainm@sympatico.ca>
wrote:

>The 'viscous' part of the fan is normally the part that causes the
>'radiator' fan to freewheel when the engine is cold and to stiffen up
>almost solid when the engine heats up so it sucks cold air to cool down
>the radiator.

I can see that you really do not know how these work either. It works
on the theory of a silicone fluid between discs that transfer power
via fluid between them due to shearing forces. The fluid is constantly
pumped out of the "disc" area into a reservior so that is can free
wheel, it starts to engage so to speak when the bi metal coil allows
fluid to return to clutch area and when it is returned at a rate that
exceeds the rate at wheich is it removed at it reaches it sate of
least slippage. It is never a solid or even should be described as
one. The fluid used has been choosen because of its shearing
properties (as rate of shear increases, the power to shear it
increases dramatically unlike motor oil) and for very high resistance
to the tempatures generated by this shearing. It is a old and proven
concept. The amount of torque this design can transfer it limited by
the diameter and amount of clutches and the cooling for them because
the shearing can generate a lot of heat. BTW, when fan engages it also
improves A/C efficency and output (if you have one) as it cools the
refrigerant more before it is expanded again which makes it cooler
when it is expanded. When clutch fans first made their appearance in
the 60's, they were mostly on cars with A/C on them and later were
used on basically all cars by early to mid 70's or so A/C or not

>
>This is a 'gas saving' device apparently saving the gas needed to spin
>the fan when the engine is not running hot. The fan does take several
>HP to spin up under load.

Yes it was designed as a gas saving device of sorts and also a way to
allow for increased cooling capacity during times of need and reduce
fan noise when it is is not needed. The only weakness of the design is
too fold, first detriot tends to be conservative with the bi metal
coil setting on some applications lets vehcile get pretty warm some
times and the second is as the mi metal coil ages by nature it will
increase engagement temp and make you think that your clutch fan is
worn out when it may only need a adjustment. As long as the clutch
does not wobble on shaft and fluid has not leaked out it is likely
still good and may at most need a little tweaking to restore its
operation. I have been tweaking them for many many years and if you
want to know how you can find instructions in link below.

http://forum.snoman.com/viewtopic.php?t=79

-----------------
TheSnoMan.com

SnoMan

On Wed, 13 Jun 2007 11:05:37 -0400, Mike Romain <romainm@sympatico.ca>
wrote:

>The 'viscous' part of the fan is normally the part that causes the
>'radiator' fan to freewheel when the engine is cold and to stiffen up
>almost solid when the engine heats up so it sucks cold air to cool down
>the radiator.

I can see that you really do not know how these work either. It works
on the theory of a silicone fluid between discs that transfer power
via fluid between them due to shearing forces. The fluid is constantly
pumped out of the "disc" area into a reservior so that is can free
wheel, it starts to engage so to speak when the bi metal coil allows
fluid to return to clutch area and when it is returned at a rate that
exceeds the rate at wheich is it removed at it reaches it sate of
least slippage. It is never a solid or even should be described as
one. The fluid used has been choosen because of its shearing
properties (as rate of shear increases, the power to shear it
increases dramatically unlike motor oil) and for very high resistance
to the tempatures generated by this shearing. It is a old and proven
concept. The amount of torque this design can transfer it limited by
the diameter and amount of clutches and the cooling for them because
the shearing can generate a lot of heat. BTW, when fan engages it also
improves A/C efficency and output (if you have one) as it cools the
refrigerant more before it is expanded again which makes it cooler
when it is expanded. When clutch fans first made their appearance in
the 60's, they were mostly on cars with A/C on them and later were
used on basically all cars by early to mid 70's or so A/C or not

>
>This is a 'gas saving' device apparently saving the gas needed to spin
>the fan when the engine is not running hot. The fan does take several
>HP to spin up under load.

Yes it was designed as a gas saving device of sorts and also a way to
allow for increased cooling capacity during times of need and reduce
fan noise when it is is not needed. The only weakness of the design is
too fold, first detriot tends to be conservative with the bi metal
coil setting on some applications lets vehcile get pretty warm some
times and the second is as the mi metal coil ages by nature it will
increase engagement temp and make you think that your clutch fan is
worn out when it may only need a adjustment. As long as the clutch
does not wobble on shaft and fluid has not leaked out it is likely
still good and may at most need a little tweaking to restore its
operation. I have been tweaking them for many many years and if you
want to know how you can find instructions in link below.

http://forum.snoman.com/viewtopic.php?t=79

-----------------
TheSnoMan.com