11 replies to this topic

[minibuck]

What's the best fan blade to have? Plastic? Metal?

[Dan]

  The late model plastic 11 blade wide tip standard one.  Unless you live somewhere really hot (as in over 30 degrees every single day) or at high altitudes where the 6 blade might be better.

[minimender]

+1   Plastic will make less noise, four blade metal makes a nice noise though I think and you can split it into two blade for the winter,  whether it shifts any more air being four blades rather than two I wouldn't know.

 

They must have tested for the multi blade fan when the mini was built and decided that 16 blades were better than the two blade fans used on Austin Morris etc vehicles at the time.

 

Just talking randomly, not an expert by any means, I tend to use electric fan but I think it does block airflow when it isn't working as the rad is only small to start with.

I have squeezed in the Austin 1300 rad in the past which is wider but not sure if it was any better.

 

As said, the later plastic fans are very efficient compared to the noisy 16 blade metal ones but if you want it to sound like an early mini then metal is the one to have 

[minibuck]

Thanks for help. What's involved in changing the fan? Take radiator off and bolt new fan on?

[Gremlin]

Yeah, exactly that

[jt19]

do you think the fan saps much power out of the engine?

 

I'm sure I read in vizards book about shortening the blades?

 

Not sure if it's worth it though lol

[Carlos W]

do you think the fan saps much power out of the engine?

 

I'm sure I read in vizards book about shortening the blades?

 

Not sure if it's worth it though lol

 

I think there are probably other ways of gaining the few BHP back that the fan uses! Take everything unnecessary out of your boot, keep your tyres inflated to the correct psi, ensure the brakes are properly adjusted and serviced, go on a diet, fit a racing battery.

 

OR alternatively, get the car on a rolling road, you'd probably notice more of an increase in performance than removing the fan and fitting an electric one.

 

With a front mounted radiator as fitted to many cars, most of the time the air travelling through it is sufficient to cool the engine, the problem with a mini is the air will take the path of least resistance which is unlikely to be through the radiator so it needs a fan that turns all the time!

[Gremlin]

IIRC the 4 blade fan took 4BHP at around 4000rpm, but don't quote me on that, I think if you put the 11 blade plastic fan on, you wouldn't notice any loss. I've got a fairly heavily modified 998 and I've just put the 11 blade fan back on and I can't notice a difference

[coopdog]

I'm fitting 2 two blade fans on my turbo build, what's people's options on them then?

I can believe it would take 4bhp from the engine....?

[sonikk4]

Unless you want to eke out the last hp from your engine i would not bother on a turbo lump. If it was NA then yes as its not so easy to get more power.

As for fitting two twin blades i have no idea how much power they would sap, at least you have the option to tweak the boost a bit with a turbo lump to compensate for losses.

 

Really at the end of the day the best and cheapest approach is what Carlos has said, shed some weight from the car, Its something like for every 10 kgs you lose you gain 1 bhp.

[mab01uk]

+1   Plastic will make less noise, four blade metal makes a nice noise though I think and you can split it into two blade for the winter,  whether it shifts any more air being four blades rather than two I wouldn't know.

 

They must have tested for the multi blade fan when the mini was built and decided that 16 blades were better than the two blade fans used on Austin Morris etc vehicles at the time.

 

As said, the later plastic fans are very efficient compared to the noisy 16 blade metal ones but if you want it to sound like an early mini then metal is the one to have 

 

A four blade fan was fitted to all home market cars,

 

 

The original Mini fan in 1959 was 4 blade metal (2 blades as above bolted together) yellow on Austin and red on early Morris cars only, all yellow from mid-way through '59 production. These were efficient but noisy........if you listen to early BMC Mini films of adverts and prototype testing you will hear the distinctive sound.

Export cars to hotter climates had a six blade export fan.  The metal sixteen blade fan was introduced in Aug 61, but was later changed to 11-blade plastic...even quieter and more efficient than the metal 16 blade as it could also be moulded with more aerodynamic shaped blades.

 

The 2 & 4 blade fans continued to be sold by BMC Special Tuning as they sapped less power than the multi-blade fans and the 6-blade export fan was available for hot climates. The power loss aspects of the quieter multi blade fans were more important in the days of tuning 850cc Mini's where every lost BHP counted.

 

Edited by mab01uk, 09 February 2014 - 07:01 PM.

[eden7842]

Stock engines plastic. Tunesd export 6 blade.