Electric fan

[spridget]

Salut

I have an electric fan in place of the original one on the water pump. It is very rusty and I don?t know where it was found. It is fitted on also rusty brackets. Then I wonder If I?d better have to change it for a new one. Kenlowes are very expensive for me so I wonder if someone tried one of the numerous ads on ebay like that one ?

http://www.ebay.fr/itm/12V-Electric-Rad ... 077wt_1080

What is the right power ? 80 W is enough ?
Another question, my radiator is a large one so is it a good idea to fit two small fans instead of only a bigger one ?
Merci !
Franck

[ericbushby]

Franck,
I have a similar looking fan on my S3 with wide radiator. It is approximately 11" diameter and is fitted at the left hand side under the water inlet pipe.
It draws 5 amps when running which at 14 volts is 70watts, so I think the power of these fans should be sufficient.
In our recent heatwave at 29C ,stuck in traffic, the waterpump fan could not cope and the water temp reached the 212F mark on the guage. 5 Minutes after switching on the electric fan it was back to 190 degrees. The engine thermostat is 82C which is 180F.
My pump has the curved tapered blades like one in the picture and is fitted with hosepipe spacers and black cable ties through the radiator fins.
I hope this helps,
Eric in Burnley,
1967 S3SE DHC (running well, Shush!)

[vernon.taylor]

Salut Franck

Those eBay fans look like the ones classicautoelec sell at double the price.

If there's no significant difference with the amount of air they can move compared to the more expensive brands, then you could give them a try. Postage is a bit expensive, though - especially for two. Maybe another eBay vendor does a better overall deal.

I'd say go for two - first because it can get pretty hot in the south of France, and second as the quality is unknown if one burns out you'll still have some cooling. If your current fan doesn't have a relay you might have to check the wiring is up to it.

@+

Vernon

[69S4]

I had the std electric fan for many years on my narrow rad S4 and the best I could say is that it err... made a contribution towards cooling the engine. It would delay the onset of overheating but it wouldn't reverse the process.
A couple of years ago I replaced it with a 10" cheepie fan like the ones on ebay.fr on the basis that it didn't cost very much and nothing ventured etc. It has made a huge difference. It's on a manual switch for the time being and when I switch it on the water temperature actually falls - at about the same rate as Eric quoted.

If I have the bonnet up - on the drive for example, the temperature falls so fast I can see the needle move and it will bring it down to the thermostat opening temperature. I've no idea on longevity but so far, two years in, it's working fine.

[worzel]

Hi

My experience only so not a recommendation.

Years ago I fitted a fan from a Citroen BX19 Turbodiesel. Has an integral cowling which makes a surprising difference to efficiency. It's push type. More like a small hovercraft really- lay it flat on smooth ground, switch on and it moves around!.
Draws a heavy current mind so definitely only fit with a relay. Mine cost ?25 from a breaker about 8 years ago- probably a bit more now.

regards

John

[Keith Scarfe]

I agree with all the above. I got one of these (exactly as the one in that listing) off ebay dead cheap thinking also nothing ventured etc.. They are more than 1/4 the cost of a well known branded one and work perfectly fine. Maybe they wont last as long but even if you have to replace it a couple of times it is still cheaper.
The only issue I have with mine is that I mounted it on the front of the rad pushing air (easy to swap blades to push/pull also) and I think it is impeding the airflow because the temp on mine runs higher than before when motoring along and struggled in this recent hot weather in the UK. I think I will change it to on the back and pulling when I get round to it to see if it makes any difference.
HTH.
Keith.

[john.p.clegg]

Keith

When you say "(easy to swap blades to push/pull also)",do you actually swap the blades or reverse them??

John

[spridget]

Many thanks mates for your replies
Eric, I?m sure the recent heatwave was a good checking, thanks !

Salut Vernon, I think you?re right about the fan burning possibility, then I will go for two. The rad is about 55cm wide and 25 cm high so I think two 9?? will be fine.
They seem to be easy to fit with the black cable ties and don?t need making new brackets
The previous fan had been fitted without relay but as I renewed the wiring loom, I have add one and a new illuminated switch!
Do you know how to choose between curved or straight blades?
Stuart, thanks too for you experience's return
Keith, I did the same on the frogeye with a CX diesel's fan (probably the same). I even kept the casing that goes perfectly in the ?mouth? behind the grill.
I tend wanting to try these new small ones, easy to find and quite as cheap
Franck

[Keith Scarfe]

Keith

When you say "(easy to swap blades to push/pull also)",do you actually swap the blades or reverse them??

John

Sorry, reverse them. You un-screw the centre nut, pull the fan balde off and reverse it and screw the nut back on. You can see the profile of the blade to get the direction correct. Then obviously swap the electrical connections to make it go the other way.
If you run the fan the wrong direction for the blade profile you can noticeably tell the difference in the volume of air it shifts just by feel.
Cheers.
Keith.

[vernon.taylor]

Salut Franck

Do you know how to choose between curved or straight blades?

I think the answer is do you want a Kenlowe copy or a Spal copy - assuming both types move the same amount of air.

@+

Vernon

[spridget]

I think the answer is do you want a Kenlowe copy or a Spal copy - assuming both types move the same amount of air.

@+

Vernon

merci Vernon
Franck

[oldelanman]

Keith

When you say "(easy to swap blades to push/pull also)",do you actually swap the blades or reverse them??

John

Sorry, reverse them. You un-screw the centre nut, pull the fan balde off and reverse it and screw the nut back on. You can see the profile of the blade to get the direction correct. Then obviously swap the electrical connections to make it go the other way.
If you run the fan the wrong direction for the blade profile you can noticeably tell the difference in the volume of air it shifts just by feel.
Cheers.
Keith.

Am I missing something here ?
If you reverse both the blade and the motor direction the direction of air flow will remain the same.......won't it ?

[elanner]

According to http://www.a1electric.com/spal/faninfo.htm :

Q. What's the difference between the straight blade fans and the curved blade fans?

A. The straight blade fans provide maximum cooling for their size. The curved blade fans sacrifice a small amount of performance in return for a much quieter fan. If noise is an issue, go with the curved blade fans. If ultimate performance is the objective, use the straight blade fans.

I have a single 9" Spal curved blade pusher fan and I can certainly hear it when it's running (when the car is stationary, of course). Presumably a straight blade would be louder. It doesn't seem to have any trouble keeping the engine cool (with a full width S3 type radiator).

Nick

[Keith Scarfe]

If you reverse both the blade and the motor direction the direction of air flow will remain the same.......won't it ?

No Definitely not. I am no expert but this is how I understand it...
It is a DC motor so swapping the polarity will reverse the motor direction thus the blade and air flow direction. Even if you do nothing to the blades it will still either pull the air or push it depending only on the direction of rotation.
If you look at the profile of the blades, they are like a wing shape with an angle of attack only in 1 direction. If this direction is the same as the direction of rotation they will shift much more air than if the trailing edge is leading. But if the trailing edge is leading the direction of airflow will still be the same. Thus you must also reverse the blades by swapping them through 180 deg.
On some of these fans, you cant reverse the blades thus you have to specify at the time of buying if you want push or pull.

[oldelanman]

Thanks Keith, I see it now.....it was a dumb question
I wonder though if those who have cooling issues with the OE electric fan may have the blades the wrong way round.