7 replies to this topic

[daniel_johno]

i was shrink wrapping all my engine bay wiring and started the engine with shrink wrap near the fan and it bent and broke a few blades off my fan...oops!!

I tried a 998 fan (also 11 blade but has different part number) but that was hitting off the breather and i am using the 2 spacers. so i left the fan off until i get a new one. took the mini to work today and although it was only a 3 mile drive the temp didnt go over halfway.

Is it true the fan is only needed when at stand still and once at speed the air is flowing fast enough to keep the engine cool?

I am driving a 60 mile trip tomorrow which is open roads all the way and dont want to get 10 miles down the road then my engine boils over.

Daniel

[Big_Adam]

Use one spacer. Then you've at least got a fan.

edit.

Oh wait. I get ya now. Hmm. I'd still suggest not driving without a fan as air dosen't flow all too naturaly over the rad unless it's angled weird.

Edited by Big_Adam, 15 April 2007 - 12:53 PM.

[Dan]

You will destroy your engine very quickly, especially in this weather. A Mini is not like other cars, the air flow through the wing is not natural and needs to be assisted. Also do not run a fan with missing blades in case you were tempted, there will be some very odd harmonics and it will probably tear itself to pieces.

[daniel_johno]

I remember reading in mini magazine a few years ago keith calver i think said the fan is of no use once at 60 and advised replacing with a kenlowe for around town when the engine heats up. Atleast i think it was minimag where i read it.

I have a flip front so i dont have inner wings so the air wont be as restricted. I now have to decide whether or not to take my trip tomorrow and chance no fan or get up super early and try space my 998 fan till it fits.

I have to day tho it seems to drive alot smoother and rev alot more freely without the fan.

Daniel

[Big_Adam]

I have a flip front so i dont have inner wings so the air wont be as restricted. I now have to decide whether or not to take my trip tomorrow and chance no fan or get up super early and try space my 998 fan till it fits.

I'll say now, if you do and you cook your engine as well as cook all the oil. Then I will be forced to laugh at you. Really REALLY wouldn't recommended it. Like how I wouldn't recommend sticking a knife in a toaster or licking electrical sockets.

[Dan]

Again someone asks a question even though they were planning to ignore the answer if it wasn't the one they wanted to hear.

A few things, firstly I don't think Mr Calver would give that advice. You may have read it somewhere in a mag but it I doubt it would be from him. It is generally regarded as a bad thing to remove the engine driven fan. There really is no reason for air to flow through the rad without the fan there and electrical fans are not designed for continuous duty but to switch on when they are really needed and then off again.
Secondly even if that were the case, are you going to be able to keep above 60 for your entire trip? As soon as you drop below this mythical speed at which the engine is self cooling the heat soak coupled with the sudden lack of cooling will cause the temperature to rocket and it will boil very fast indeed.
And lastly, of course it will rev higher with the fan removed. It would be even smoother and easier revving with the oil pump, water pump and alternator disconnected too, doesn't mean it's a good thing.

The radiator core itself is what restricts the flow of air, with no inner wings there is even less reason for air to flow across the fins. It will just flow around and bypass the rad entirely. Air has to be forced to go through the core because it is restrictive.

Still what do I care if you boil your car?

Edited by Dan, 15 April 2007 - 11:10 PM.

[Spinksta]

Again someone asks a question even though they were planning to ignore the answer if it wasn't the one they wanted to hear.

A few things, firstly I don't think Mr Calver would give that advice. You may have read it somewhere in a mag but it I doubt it would be from him. It is generally regarded as a bad thing to remove the engine driven fan. There really is no reason for air to flow through the rad without the fan there and electrical fans are not designed for continuous duty but to switch on when they are really needed and then off again.
Secondly even if that were the case, are you going to be able to keep above 60 for your entire trip? As soon as you drop below this mythical speed at which the engine is self cooling the heat soak coupled with the sudden lack of cooling will cause the temperature to rocket and it will boil very fast indeed.
And lastly, of course it will rev higher with the fan removed. It would be even smoother and easier revving with the oil pump, water pump and alternator disconnected too, doesn't mean it's a good thing.

The radiator core itself is what restricts the flow of air, with no inner wings there is even less reason for air to flow across the fins. It will just flow around and bypass the rad entirely. Air has to be forced to go through the core because it is restrictive.

Still what do I care if you boil your car?

Actually, Mr Calver did say something similar which could be taken to mean the same thing if not thought about a great deal. In fact exactly what he said is just here: (taken from the cooling section of his site http://www.calverst.com/CC110F.htm)

Fans. They’re there to cool the engine whilst at low speed. Fact. Once above 35 mph or so, it’s airflow through the radiator that does the cooling. Electric fans only help up to about 30 mph, so fitting one won’t cure hot running at speed. The fan creates a barrier to airflow at speed; trimming the blades down in length (NOT removing blades) can often help.

So he doesn't actually say that you don't need a fan above 35mph, as, like you say, air still needs to be drawn through the radiator, but I can see how it would be easy for someone to think that's what he meant.

Just to clear that up.

[daniel_johno]

Thanks for that spinksta, I did fit another fan i borrowed off a friend after the reply i got from Dan which decided to shatter itself 10 miles into my journey ( was catching on the breather) and i managed to drive the rest of my journey with the temp not going over half way on the gauge. Ordered new fan and going to take hammer to breather to gently persuade it to keep away from fan blades.

Daniel