Engine: Jaguar thermostatic fan clutch adapter

[delavant]

I was wondering if there is any demand for an adapter to install a Jag thermos clutch fan in a 63-64 Avanti. I understand at one time there was a gentleman by the name of Dan Miller who sold some kind of kit but they are no longer available. I had one made for my 63 Avanti that works very nicely and doesn't change the fan depth and isn't noticeable without close scrutiny. I have designed an improved version and if there is enough demand I will see if economy's of scale might reduce the production cost enough to make it feasible. Thanks for any input.
Larry

[64V-K7]

I have a very well qualified friend who used a lathe to make the Jag clutch work on his Avanti. In the end, he wasn't confident that there was enough meat left to support the intended purpose. Can you put up a few pics, etc?

[Bullet]

If you get it to work on a Lark style then the demand would be there. I had a non-jaguar one made for my lark but it was too long and was not installable because it made the fan it the radiator.

Mark

[delavant]

I don't know what your friend did but if it's in regard to the flange diameter I saw that issue from the beginning and your friend was right to be concerned. My design addresses that very situation and if enough interest is shown and I progress to the production stage I will provide all the information for a buyer to make an informed decision. It's really too bad that Jag flange is so small otherwise the adaption would be a walk in the park. Thanks for your interest.
Larry

[delavant]

If you get it to work on a Lark style then the demand would be there. I had a non-jaguar one made for my lark but it was too long and was not installable because it made the fan it the radiator.

Mark

I may get there but right now I'm concentrating on the Avanti set up, thanks for your interest.

[JoeHall]

How about designing an adapter to use with any of the generic fan clutches with the .625" hole? Those account for about 99 percent of the clutches available. Other than a slightly larger pilot hole, what's the big deal abut a Jag fan clutch?

[64V-K7]

....what's the big deal abut a Jag fan clutch?

Most all available fan clutches today are viscous. A Jag clutch is also thermostatic, like the original Avanti. The thermostatic bit helps the power range a bit more, as it won't force the fan to turn until the temp of the radiator air flow exceeds a given figure. Once the thermostatic spring engages, then the clutch is engaged and the fan will require engine power to turn. The rpm will be lower because the viscous fluid acts as a 'gear down' so larger fan blades can be used to draw more air through. A straight viscous fan clutch will force the fan to turn, from a cold engine start....

[JoeHall]

Bob J.,
I thought Studes originally came with viscous, which runs all the time. I believe thermostatic clutches are later technology, run only as needed, and are available at most FLAPS. All three of my Stude Hawks (two GTs and a 56J) have Hayden brand, .625" pilot holed, thermostatic clutches; even better, I was able to choose between normal, heavy and severe duty versions. I chose the severe duty, but would likely use HD next time. They kick in upon startup for the first 3-5 minutes, then all but shut off, and kick in & out as needed while driving. Need is determined by air temp coming through the radiator and blowing on the thermatic metal strip across the front of the clutch.

[64V-K7]

Here's a pic of an original Avanti fan clutch...

[JoeHall]

I think terminology is confusing us both. There are two types of viscous clutches: thermal and non-thermal. Pretty sure the one you posted is non-thermal. I used the term, "thermatic metal strip" but shoulda used the term, "bi-metal thermal spring". The expanding/contracting coil spring is what aligns the internal passages to increase/decrease fan engagement in a thermal clutch. There is no such spring on a non-thermal. This info from Hayden may help: http://www.haydenauto.com/upload/Hay...gn%20Types.pdf

[JoeHall]

Here's a pic of an original Avanti fan clutch...

[ATTACH=CONFIG]52988[/ATTACH]

I stand corrected. I did some more reading, and learned the bi-metal strip, as is on the Avanti clutch, does the same thing the coil spring does on the Hayden. It is indeed, a thermal fan clutch. As mentioned before, both thermal and non-thermals are viscous. Having read the difference between thermal and non-thermal, I'd choose a thermal any day of the week. Both types are readily available for just about every make of car, not only Jaguars.

[delavant]

How about designing an adapter to use with any of the generic fan clutches with the .625" hole? Those account for about 99 percent of the clutches available. Other than a slightly larger pilot hole, what's the big deal abut a Jag fan clutch?

For the Avanti owner (which is what I am addressing right now) the big deal are the other dimensions, it is the only fan clutch that comes so close to Avanti clutch in regard to depth into the shroud, distance from radiator, etc. If the pilot hole was the only issue it would be a walk in the park.

[JoeHall]

Thanks for clearing that up. Still, to gain more perspective buyers, one adapter could be made for all Stude applications, since the Jag clutches come with a spacer to step the .750" pilot hole down to the more common .625" hole.

[delavant]

Thanks for clearing that up. Still, to gain more perspective buyers, one adapter could be made for all Stude applications, since the Jag clutches come with a spacer to step the .750" pilot hole down to the more common .625" hole.

Did you know the Avanti pilot is 1 1/16".

[JoeHall]

Did you know the Avanti pilot is 1 1/16".

I measured 1.057" on a Stude water pump. Not sure if an Avanti is .005 larger, but even if so, should not be a problem with an adapter to fit both.