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electric fans

Posted: Sat Nov 17, 2007 7:24 am
by smokeyone
What's the best advice on installing an electric fan in a 3.9 rr classic.
I am now on my third vicious coupling fan and wondered about giving an electric one a try.
A trip to the breakers or is it a kenlowe purchase job !
Also I found this on this forum, is this where to start
http://www.x-eng.co.uk/X-Therm.asp?MID=38

Cheers

http://cgi.ebay.co.uk/Range-Land-Rover- ... dZViewItem

PS Just found this on e bay but could be a bit small

Posted: Sat Nov 17, 2007 9:29 am
by Ian Anderson
I would think a single 13 inch fan would be too small

Perhaps get away with a single 16 or 17 inch or twin 10 - 11 inch

The cooling all comes down to airflow through the rad and although the small fans are great for a V8 they probably don't cut it.

See http://www.nfauto.co.uk/ on their main catalogue page 32 it gives the CFM rates for the fan sizes, Also has mounting kits etc.

Suggest also run the fan through a relay as they draw mega current especially on start up and then also wire in manual override switch in case the thermostat one goes iffy

Ian

Posted: Sat Nov 17, 2007 10:46 am
by smokeyone
Thanks very much for the advice. I am not familiar with the company, their catalogue is full of goodies !
Fan size seems to go upto 16", wonder if it's worth having the curved version. Do you know if the curved blades are more efficient like the new generation of prop airliners or it might be the curved blades are quiter !
Thanks again

Posted: Sat Nov 17, 2007 11:20 am
by Coops
I went to the breakers and used the fans from a renault espace, they are huge and are housed in there own plastic sourond with fixing lugs, there is also a compartment on the side for the relays to live in,

Citreon and peugeot also have twin fans in a plastic housing, i know the old c15 vans did.

Posted: Sat Nov 17, 2007 11:45 am
by Pocket rocket
Try the fan from diesel escorts. I use one in my cobra (Sumo) and don't have any problems. veru efficient fan - blows a gale! 8-)

AFAIK curved blades are more efficient

Posted: Sat Nov 17, 2007 11:49 am
by Ian Anderson
I've no relationship with Car Builder other than being a very satisfied customer everything has always been delivered overnight. OK on some things they may not be the cheapest but the service is always first class.

I believe the curved fans are quieter and I have also heard it said they are more energy efficient which is also a good thing.

Just remember running an Efi engine
Approx 10 amps for fuel pump
About 2 amps for Ecu
Headlights etc 20 amps
Then have another 2 fans at 10 plus amps each and you may draw more than your alternar produces

So it is worth checking everything out.

That said Tony's Espace shroud unit sounds good and if from a breaker a cheap option.

Ian

Posted: Sat Nov 17, 2007 5:05 pm
by smokeyone
Thanks again for all the advice especially about checking the alternator !