A fan question

Phillip and Mario are correct, when have my cooling issues recently i had the fans come on a few times.
Once i fitted a new viscous unit the difference was amazing, temp would very slowly rise to operating temp after about 15 mins of driving then the fan would cut in and temp would drop by about a needle width.

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Originally Posted by johntins

I have read that as well, but it makes no sense. VC fans do nothing at low revs. regardless of the engine temp, because they need revs to make them work. They work at high revs, but by then you are already stressing the engine. IMHO they are the most useless addition to a cooling system ever, unless you count the FIAT electro/clutch fan on the 124.

Electro fans, such as the EF/EL Ford type that Mario mentions, run off a switch set at the right temp, located in the right place, will beat a VC fan every time.

It's a pity they don't also run to a water pump. That would be a perfect world.

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I think the reason mentioned was they just don't suck or push enough air through when needed in off roading a viscous I think draws more through as it has big blades as opposed to the piddly El fans.
Maybe you could fit a hiclone to the fan?;)

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Originally Posted by loanrangie

Phillip and Mario are correct, when have my cooling issues recently i had the fans come on a few times.
Once i fitted a new viscous unit the difference was amazing, temp would very slowly rise to operating temp after about 15 mins of driving then the fan would cut in and temp would drop by about a needle width.

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If your old VC was faulty, then obviously a new one will improve things. A working VC fan is better than no fan at all.

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Originally Posted by Roverlord off road spares

I think the reason mentioned was they just don't suck or push enough air through when needed in off roading a viscous I think draws more through as it has big blades as opposed to the piddly El fans.
Maybe you could fit a hiclone to the fan?;)

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That is only the case if the engine is revving. Low speed, low rev crawling, often the case when off roading is where I believe a VC lets you down.

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Originally Posted by johntins

That is only the case if the engine is revving. Low speed, low rev crawling, often the case when off roading is where I believe a VC lets you down.

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Having said that, I need to say that mine still has a VC. With the head done, and having kept Mario solvent with all the new parts I put in, and a clean radiator, I'm struggling to get mine warm. Which is a better state of affairs than how it was before:)

A functioning viscous fan will lock up at low rpm and still draw far more air than aftermarket electric fans.

More demanding slow driving in heavy sand, where vehicle is moving slow but engine rpm are higher, again the viscous fan will be far better than electrics.

Land Rovers of old have always had a good cooling setup with the viscous fan and the electrics (twin on old, single on newer) that as mentioned turn on with temp and also with a/c on.

Regards
Daz

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Originally Posted by johntins

If your old VC was faulty, then obviously a new one will improve things. A working VC fan is better than no fan at all.

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Yes but what i'm saying is when working correctly they work well and better than any electric fan.

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Originally Posted by DazzaTD5

A functioning viscous fan will lock up at low rpm and still draw far more air than aftermarket electric fans.

More demanding slow driving in heavy sand, where vehicle is moving slow but engine rpm are higher, again the viscous fan will be far better than electrics.

Land Rovers of old have always had a good cooling setup with the viscous fan and the electrics (twin on old, single on newer) that as mentioned turn on with temp and also with a/c on.

Regards
Daz

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If it ain't broke why fix it, that's probably why land rover stuck with VCs instead of ditching them and going all electric

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Originally Posted by johntins

With the head done, and having kept Mario solvent with all the new parts I put in, a:)

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:twobeers::Rolling::Rolling::Rolling::Rolling::Rol ling::Rolling::TakeABow::TakeABow::TakeABow::TakeA Bow:

I once saw an analysis that said that a Range Rover viscous fan drew about 7Hp when locked.

If you work out how many amps that is at 12volts it is about 400 amps.

7Hp =5291 watts Divided by 12 =440amps

Now show me some 200amp fans if you have 2 of them.
Regards Philip A