Got a few cracks in my viscous fan been offerd a s13 200sx one they look the same does anyone know if they will fit /same size thanks.;)

without looking at my Z one,

 

the S13 one is attached to a block, with 4 screws onit,

 

unsure if they will line up with the 4 on the Z?

There is a new one on ebay for sale starting at £50 with no bids...........

Try Zedworld in Tamworth, they have always got a load of Zeds for breaking and would only send you out a real solid one.

Or put an electric one on and save fuel (probably) and as they are not on all the time they can be less noisy..

Or put an electric one on and save fuel (probably) and as they are not on all the time they can be less noisy..

 

lol, they dont cost fuel!

 

and as for 50 quid on ebay, thats way overpriced!

 

ask on driftworks, youl get 1 for a tenner!

A viscous fan does cost fuel. Simply put, if it blows air it takes energy to drive it. And its being driven 100% of the time.

That why you put light weight pullys on so there is less weight to turn

All adds up, inc light weight flywheels too.

So am I right in thinking a new fan from Nissans is only a £10?

Viscous fans aren't as bad as people are making out. While it's true that they're driven all the time this does not mean that they're costing fuel all the time. When you're driving along at a certain speed the natural airflow through the radiator will act to turn the fan so the amount of energy required to turn it drops to almost nothing. That's one reason why a viscous coupling is used instead of just direct drive.

 

At low speeds it might be turning all the time but the energy transfer between the engine and the fan is almost 100% through the viscous coupling. By comparison, an electric fan is driven by a DC motor which is fed from the alternator. DC motors are really inefficient and alternators aren't much better at converting energy so when the fan is running it is you'd be lucky to get 30% efficiency with the energy transfer. Obviously it makes this back by being thermostatically controlled so overall the electric motor would use less energy but there is another factor.

 

As our cars are very sensitive to overheating i prefer to stick with a viscous coupling for purely reliability reasons. The only 2 realistic failure points in the viscous system are the coupling and the fan. In the electrical system you've got the thermostat, the electrical connections, the cabling, the fuse and the DC motor (containing all manner of brushes, bearings, etc).

 

Obviously the electric system does have advantages and you will get a slight increase in RWHP but, for me, it's not worth it.

 

Dave

dave, are you an engineer by any chance? because thats a great overview of the compromises of viscous over electrical