Rad Fans?

Post by **Coops** » Sat Jun 29, 2013 10:55 am

having a few issues trying to keep the cappa cool,
running a pair of 10" fans but dont really think they are up to the job to be honest as once they come on they dont turn off until you have been for a drive up the road, and in traffic the temp gauge slowly climbes into the red with the fans on,
the old setup use to come on and off sat in traffic ,
had to change to these slim line fans due to the intercooler sat now in front of the rad where the old fans lived.
i just dont think these new ones shift enough air to be able to draw through the intercooler too,

any recomendations?

DaveEFI · Post by **DaveEFI** » Sat Jun 29, 2013 12:28 pm

Fans should say in their spec how much air they shift - if you don't know this figure for yours, I'd say they're not decent ones.

The 'resistance' of the inter cooler will also make a difference to the flow through the main rad.

Ian Anderson · Post by **Ian Anderson** » Sat Jun 29, 2013 1:39 pm

10 inch fans are IMO fairly worthless. You will get perhaps 650 CFM through each so about 1300 all in

A decenct single 16 inch one will move about 3000CFM.

You do the maths!

You need volume of air to move the heat away from the rad?

Now can I ask a seemingly stupid question? Are they drawing air in from the front and moving towards the rear of the car? I have seen them wired backwards and blow against the natural air flow thus stalling the radiator. I have also seel one correctly wired and one backwards so ot tended to move the airport around in circles.

Ian

DEVONMAN · Post by **DEVONMAN** » Sat Jun 29, 2013 1:55 pm

Also, If they are a good quality fan, the blades will be shaped to cut the air efficiently. So you need to check that the blades are the correct way round on the motor spindle and if not take them off and fit them the other way round. On my fans, they are stamped B on one side and S on the other which stands for blow and suck.

r2d2hp · Post by **r2d2hp** » Sat Jun 29, 2013 2:42 pm

I have the same problem Tony.

Rad was purpose built for mine and is fitted with 2 fans from Kenlow.

http://www.burtonpower.com/kenlowe-elec ... f12hp.html

http://www.burtonpower.com/kenlowe-suct ... 10hps.html

Mk1 only has a very small area to take air and with intercooler would sit at about 95 in traffic which was a concern but it never boiled over. The small intercooler was also limiting boost so it had to go.

What rad did you change too as your renault rad always worked perfectly.

Will test again next week

Ian Anderson · Post by **Ian Anderson** » Sat Jun 29, 2013 6:32 pm

Have a read here
http://www.a1electric.com/spal/faninfo.htm

Ian

Post by **Coops** » Sat Jun 29, 2013 7:11 pm

Hi Reg,
im still using the ally audi rad,
just with a pair of slimmer 10" fans,

Ian, no chance of running a single 16" fan due to space issues mate,

Post by **Coops** » Sat Jun 29, 2013 7:43 pm

may get away with 2x 11" with a slight overlap of the side tanks

seight · Post by **seight** » Sat Jun 29, 2013 8:01 pm

Well I guess an 11 inch fan gives you 20% more coverage over a 10 inch (all else being equal) so it's a start. But fan speed and blade shape have an effect. Don't forget a fan shifting considerably more air will draw more leccy too.
Mike

gelmonkey · Post by **gelmonkey** » Sun Jun 30, 2013 8:07 am

Tony
As Ian says a decent 16 " fan will shift about 3000cfm.
I got mine from Be Cool and it made a huge difference to the cooling to my motor.
As you know there is very little open space at the front of my car and the BE Cool fan worked a treat and I never have a problem now and it cost less than a £100.00.
I can't remember how thick the fan is exactly but seem to think that it's less than 2 1/2".
Can you get something like this in?
cheers
P

Post by **Coops** » Sun Jun 30, 2013 10:00 am

like i said mate no to a 16" fan,
no room in the front due to oil coolers and intercooler,
and defo no room for a 16" fan in the front,
may have a pair of cossie 11" fans coming that work with said intercooler etc, so worth a try,
failing that spal do a 3000cfm fan for £300

Ian Anderson · Post by **Ian Anderson** » Sun Jun 30, 2013 10:35 am

Is there an exit route for the air once it has been through the rad?

Bonnet fins etc make a huge difference

Sort of like intercooler. Rad. Fan. Pipes. Engine
Will be better than inercoolerradfanpipesenginebulkhead

Nowhere for air to go

Iqn

DaveEFI · Post by **DaveEFI** » Sun Jun 30, 2013 11:47 am

A UK SD1 with air con has twin fans. Export models to hotter countries a single larger one. Since there obviously is no space issues, I assume two small fans cost less than one large one? Or is it something else?

stevieturbo · Post by **stevieturbo** » Sun Jun 30, 2013 5:50 pm

Is it only traffic the problem occurs ?

Ensure no frontal air can bypass the rad. And ensure no hot engine bay air can re-circulate to the front of the rad again.

How are the fans attached to the radiator ? And do they cover as much of the core as possible ?

Puller fans are more efficient than pushers. Some fan blades can go either direction, many cannot. So are you using the fan as it was intended ?

And the obvious one....stat etc working ok ?

DEVONMAN · Post by **DEVONMAN** » Sun Jun 30, 2013 7:38 pm

Ian Anderson wrote:
Bonnet fins etc make a huge difference

Iqn

I agree,
My system was marginal in traffic until I added some neat louvres to the bonnet. Now I can sit all day in traffic with the fan switching on and off.

On a Capri the hot air from the vents could find it's way into the heater inlet so careful positioning of the vents is needed. Also, fumes from a smelly engine (I'm sure your isn't) could find their way into the cab.