15 replies to this topic

[KEV@POWARTEK]

Ive currently got a 7 blade steel fan on mine, Im just wondering if there is any benefit of changing to a 4/5 blade plastic fan?


Kev.

[*DJH*]

from what i recall, metal fans are supposed to be more effective at cooling than the plastic ones, but the plastic ones make less air noise then the metal fan

[KEV@POWARTEK]

what about the effect of weight?

[rick.spi]

there was a thing on it in one of the minimags/worlds and it came to the conclusion that the later plastic fan was best.

Edited by rick.spi, 27 August 2009 - 07:06 PM.

[MRA]

The six bladed .............. (shameless plug)

http://mra-minis.co....;products_id=53

Is by far the best for moving air and is what is commonly known as the "hot climate" or "temperate" fan

The 11 bladed plastic type ............ (another shameless plug)

Yellow - http://mra-minis.co....;products_id=55
Clear - http://mra-minis.co....;products_id=54

are very good all rounder, good air flow and quiet, whilst also being flexible enabling easier fitment of radiator and or belt.

The 4 bladed fan is better at moving air than the plastic type but a lot noisier and there have been some quality issues with the thinner material that some of these were made from

http://mra-minis.co....;products_id=52

The weight issue ......

Heaviest is the 6 bladed fan at 510g
followed by the 4 bladed at 320g
closely followed by the plastic fan at 300g

Edited by mra-minis.co.uk, 27 August 2009 - 09:55 PM.

[Nightrain]

Would agree with that martin, but in real life the plastic fan moves more air where you need it to, at lower rpms/tickover. When stuck in traffic etc and Im talking from experience here.

Another alternative would be the Dowty Variable Pitch Fan.

Edited by Nightrain, 27 August 2009 - 10:43 PM.

[Retro_10s]

Another alternative would be the Dowty Variable Pitch Fan

I was looking at one of those on Ebay last week - went for £10 which i thought was a good bargain really.

[Mr Joshua]

Would agree with that martin, but in real life the plastic fan moves more air where you need it to, at lower rpms/tickover. When stuck in traffic etc and Im talking from experience here.

Another alternative would be the Dowty Variable Pitch Fan.

and at higher rpm the plastic fans when fitted on performance engines they can struggle to keep it cool again speaking from experience.

So its a catch 22

[Nightrain]

Would agree with that martin, but in real life the plastic fan moves more air where you need it to, at lower rpms/tickover. When stuck in traffic etc and Im talking from experience here.

Another alternative would be the Dowty Variable Pitch Fan.

and at higher rpm the plastic fans when fitted on performance engines they can struggle to keep it cool again speaking from experience.

So its a catch 22

LOL at higher speeds nearly all the air moving through rad is caused by the car moving forward !!!

[Mr Joshua]

funny that when I switched to a 6 bladed metal fan my issues went away but I guess only your experiences count.

[Nightrain]

funny that when I switched to a 6 bladed metal fan my issues went away but I guess only your experiences count.

LMFAO and what where you problems ?

[Mr Joshua]

engine temp would creap up while during long runs at high rpm. Put a six blade fan on instead and no more issues.

[minitomfoolery]

engine temp would creap up while during long runs at high rpm. Put a six blade fan on instead and no more issues.

+1


That was my problem until I put a metal fan on aswell

[Cooperman]

The more blades you have the more likely you are to get 'cascade effect' at very high revs. This happens when the speed of the blades causes the fan to become, in effect, a solid disc (in fact, this effect is also known as 'disc-ing').
The plastic 11-blade fan seems good up to about 5000 rpm (engine speed and with the small water-pump/fan pulley).
For sustained high revs the 6-blade, or 'export' fan is excellent, as is the old competition 4-blade. Less blades seem to increase the engine noise.
Who can remember the early 16 blade steel fans which 'disced' at about 4500 rpm? Useless for any high-performance use.

[stormintrooper]

mra....shameless
but fair play