Engine: Hydrostatic cooling fan drive

[skycar]

I am about to change the original pulley driven 4 blade fan on my 289 engine '62 Hawk, to a "hydrostatic driven 5 blade fan".
I have a choice of 2 drive hubs to use, one moves quite freely and the other is noticeably stiffer and harder to turn by hand.
From this description can someone please tell me which is the better unit to use?
Thanks in advance for the wealth of knowledge here,
regards from Australia

[jimmijim8]

There are 2 types of fan clutches. Thermostatic and viscous. Do a search for Hayden products{ the manufacturer}. On their website they have information explaning of the differences between the 2. cheers jimmijim

[bezhawk]

I don't see any advantage over a belt driven fan, as the water pump will still need to be driven in some manner. Unless you are going to an electric driven water pump, you will still have loses. How are you driving the hydrostatic motor? The pump is still a power drain, so nothing really gained.
If you are talking about thermal viscous couplings, that is an entirely different nomenclature.

[skycar]

It seems like I have my description incorrect, it is a thermal viscous coupling type.
Regards Roger

[bezhawk]

I prefer the type that is easier to turn when cold. The thermal clutch in it makes it couple better as the temperature rises. The stiffer when cold type just use an oil coupling much like a torque converter, and don't cool as well.http://www.haydenauto.com/Fan%20Clut...2/Content.aspx

[Corley]

I went through about 4 of those suckers on my GMC motorhome, before finally getting one that actually would cut in and start spinning the fan when temps got around 200F. It is the type that turns hard cold, and the fan is engaged when you first start the engine, and for about 30 seconds, then it mostly disengages, until you hit 200F, then the fan comes up to speed with a huge roar. Since on that vehicle you are sitting just above the fan, you can't miss it when it engages. It is a Hayden. The first three that did not work (new), were not Hayden, CRS prevents giving specifics. Got this one at Autozone about 15 years ago and it still functions as it should. My experience is that most of those other brands are junk.

Since all that hassle getting a good one for the MH, I've noticed that the ones on my other vehicles seem to operate the same, stiff when cold, lock up for about 30 seconds, then free wheel and quiet down until needed... Just what I've found, nothing more...

PS If it doesn't have the little bimetal coil spring on the front of it, throw it away! Without that, it would be just a fluid coupling, not thermally activated clutch. JMHO

PS/2 Someone told me a million years ago to not lay these on there side, after they have been used, rather keep them upright. The seals tend to leak on older ones, and if the fluid leaks out it is also junk.

[skycar]

Thanks Corley and others here, this is the info I was after ....... regards Roger

[RadioRoy]

[QUOTE=Corley;811670]

PS/2 Someone told me a million years ago to not lay these on there side, after they have been used, rather keep them upright. The seals tend to leak on older ones, and if the fluid leaks out it is also junk.[QUOTE]

I'm confused. Aren't they "on their sides" all the time they are installed?

[StudeRich]

The Original Hydraulic Oil Filled Thermostatic "Studebaker" Fan Clutches, always said: "Store face up" with an Arrow ^ apparently long term storing and running have two different affects on them.

[Corley]

[QUOTE=RadioRoy;811747][QUOTE=Corley;811670]

PS/2 Someone told me a million years ago to not lay these on there side, after they have been used, rather keep them upright. The seals tend to leak on older ones, and if the fluid leaks out it is also junk.

I'm confused. Aren't they "on their sides" all the time they are installed?

Maybe I should have said, "you should keep them in their 'as-installed' orientation, when you remove one"... I don't know anything about new, on the shelf, storage.

[DEEPNHOCK]

Last time I drove a '63 Avanti on a hot day, when the fan kicked in...
I thought a C-130 was buzzing the car...
Man, that fan blade makes some kind of air noise...