Viscous clutch fan time - Need some clarification

[alexbrown64]

On a hot day with my ZJ fan, temps at idling will creep up to mid way on the dash, but my Engine Watchdog says it’s only 92-93C.
If I increase the revs in the driveway a bit, I can see the dash gauge and Watchdog instantly start to come down. This tells me the fan is drawing in huge amounts of air and really working at cooling her down. I’m not sure if there is much difference at idle between a ZJ and XJ fan. But at revs, you can hear the difference and witness the difference on the temp gauges.

Cheers,

[Sobek]

The more I drive the more I would agree - at idle it's about as effective as the stock fan ever was. But as soon as you're moving at all, it's far, far better, moves so much more air and temps drop pretty rapidly even on a stinking hot 35c+ day. The one thing I've noticed most of all is with uphill driving. Where I live it's fairly hilly, and I often drive uphill a fair bit to go to certain shops or parks where I go fossicking, and on the stock fan temps would always gradually work their way up towards 100c while doing sustained uphill stretches. On this ZJ clutch, I can drive the whole way up and it's always sitting at about 75-80c at most. Even if I stop at some lights and it creeps up a bit, as soon as I start moving again the temps drop off rapidly.

So yeah, at lower speeds you won't notice the difference a whole lot. But if you're highway cruising, going fast-ish or doing uphill drives or anything that keeps the rpm's up, it's a world of difference!

I'm very happy so far

[LuluBelle]

Cool Sobek I am still waiting that's what I want highway cooling
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[Sobek]

I think you'll like it

I forgot to mention, reading about this clutch I always saw people talking about power losses. The butt dyno tells me nothing has changed, but I FEEL like I'm having to push it a bit harder. I think my mind is playing tricks on me, because the increase in noise kind of makes you THINK your motor is working harder, so in turn your brain thinks you're doing the same. But I think it's basically the same as stock. I've never really watched my economy in the jeep, because honestly why even bother, but I'm preeeetttty sure it's basically identical.

Good luck!!

[LuluBelle]

still waiting
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/__l_l_,\____\,___
l_---l_l__l---[ ]llllll[ ]
_.(o)_)__(o)_)--o-)_)

[LuluBelle]

Ripped Off my fan arrived from rockauto today I will fit really soon I didn't get a fridge magnet from rockauto I was hoping to add to the collection
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/__l_l_,\____\,___
l_---l_l__l---[ ]llllll[ ]
_.(o)_)__(o)_)--o-)_)

[awg]

[QUOTE=LuluBelle;1657430]Cool Sobek I am still waiting that's what I want highway cooling

afaic , poor highway cooling is not the fault of the the VC fan, but some other cause such as partially blocked radiator or internal engine cooling passages partially restricted with scale and sediment

all my XJ run cool once they are traveling above 60kmph

If the ambient temp is above +35C, they will tend to run around 91-105C

(within spec)

I know it is very hot in your location

the best test (if engine temp is too high at speed) is to run the heater with fan on full..if temps fall..its a circulation issue