9 blade fan conversion

30csl · Mar 23, 2010

Does anyone have any pics of a 9 blade fan install up close - the gus restoring my car seem to be having problems with it interfering with the radiator even though I have oredered the thinner radiator to accomadate this.

I installed one on my own rhd Csl without any problems although the clearance is tight.

Anyone had problems and know the cause? The red fan fitted fine beforehand so I suspect something silly is being missed when installing it or W and N sent a wrong part in the kit.

Thanks,

Rohan

oldcoupe · Mar 23, 2010

Fan Clearance

My fan upgrade was too close for comfort, so I spaced it back off the fan clutch using a few washers to get that extra few millimetres, however your problem sounds more serious. Has your guy put the fan on the correct (rear) face of the clutch.....?

30csl · Mar 23, 2010

Hi there, I was talking about clearance with the radiator rather than the engine? Do you mean you were too close to the engine? I ordered the kit from Walloth as I have done in the passed so not sure what has gone wrong! Anyone got some close up pictures?

Unless there is a different pulley it should be straightforward??

oldcoupe · Mar 23, 2010

Fan Clearance

I meant the clearance between the fan and radiator. Mine was a bit close - probably PO damage - so a few millimetres has helped- hence the washers between the fan and fluid coupling.

The BMW fiche at eg http://bmwfans.info/parts/catalog/E...ober/browse/radiator/radiator_thermostat_fan/ is misleading.

The order shown should be bolt 1, then coupling 3 set in the depression in the fan centre, then fan 2 and nut 5. The assembly is then mounted on flange 6, using bolt 10 and spacer 8. Flange 6 is bolted, with the pulley, to the water pump. Thus the dish or depression in the fan faces forwards. The radiator must be removed to install the assembly. I'm told that if you use the E28 arrangement instead you can a) remove the fan leaving the radiator in b) use the 32mm nut to rotate the engine when setting the tappets

Photo of my setup attached.

I'm sure this is clearer to the writer than the reader.

m_thompson · Mar 23, 2010

My fan is very close to the radiator but has been OK for 27 years. Someday I plan to put the flange in a lathe and cut about 5mm from the cone to allow the clutch to move away from the radiator.

hans3 · Mar 23, 2010

Someone else mentioned that worn engine mounts may cause the engine to lean too far towards the radiator. Conversely, new mounts will raise the front of the engine to give a little more clearance. My motor's position definitely changed when I installed new mounts vs. the originals.

30csl · Mar 23, 2010

Thank you all - this is incredibly helpful.

Such a brilliant forum as ever!

This should get us sorted.

Thanks

bert35csi · Mar 23, 2010

Rohan,

Are you guys using the old fan coupler from the CS or the later viscous clutch couplers from the later BMW units such as the ones from the 6 series? There are 2 types of viscous couplers available. The first generation couplers as used on cars up to 1979 use 4 bolts to mount the fan/clutch assembly to the water pump housing, whereas the units from 1980 onwards use a single large nut to mount it to the water pump. The latter type single nut version will give you an extra few valuable millimeters of clearance. Also, by going with the single nut mount, a new single threaded bolt water pump is needed.

As mentioned earlier, install new motor mounts for added protection and insurance against the fan hitting the radiator. Having killed 2 radiators in my first CS in the early 90's, due to hard braking situations and weak, old motor mounts, I can attest to the importance of having extra clearance between the fan and the radiator.

deQuincey · Mar 23, 2010

may I recomend you my post full of pics

http://e9coupe.com/forum/showthread.php?t=6020

I upgraded the old 1971 version to a new one by walloth

hope it can help

do not hesitate to ask questions

regards

deQuincey · Mar 23, 2010

old coupe is right

The BMW fiche at eg http://bmwfans.info/parts/catalog/E...ober/browse/radiator/radiator_thermostat_fan/ is misleading.

the mentioned fiche is wrong !!!

mostly because you have to turn the fan on the contrary position (the front face should be the rear face)

walloth recognised that the presented drawing is wrong, I realised it when I saw the geometry of the fan blades compared to the spin sense of the fan, if you place it as in the drawing the eficiency of the fan will be quite bad

I can explain better if anyone needs it with a small drawing

deQuincey · Mar 23, 2010

this is the way to repair your problem

deQuincey · Mar 23, 2010

30csl said:
Anyone had problems and know the cause? The red fan fitted fine beforehand so I suspect something silly is being missed when installing it or W and N sent a wrong part in the kit.

Thanks,

Rohan

no, no rohan

W&N did not sent anything wrong, but they miss to say you that the original drawing in bmw is wrong !!:-D:-D:-D

this is the correct assembly position of fan regarding to visco-clutch

and you may note that the clearance is enough

regards

30csl · Mar 30, 2010

Thanks guys, this is very helpful and you have all gone to a lot of trouble to show me the error.

Much obliged,

Rohan

Bill Riblett · Mar 30, 2010

My solution is much simpler. I just cut off the front parts of the rubber cushions on the radiator side mounts and stuck the cut-off piece to the rear to force the radiator forward. This got me an extra 3/8" (10mm?) clearance. It has been years since I did this, so I don't remember for sure, but I think there must also have been bottom cushions that I would have cut too.

The placements of the cores in my two cars' radiators is very different. In the car pictured below, the core face is to the rear of the radiator side tanks. In the other car, the core is forwards perhaps 3/4-1" so that has plenty of room for the fan.

In the first picture, you can see the cut up rubber cushion. The second picture gives some idea of how much clearance I have.

DaSurfa · Jul 23, 2013

Anyone have the part number for the fan and fan clutch for the fan in the above pictures?

I just changed my water old pump which had a large screw on bolt for fan to mount and my new water pump is the same as the one in deQuincey's thread with the flat mount.

Or if anyone has an extra one for sale it would great as well.

Thanks,
David

HB Chris · Jul 23, 2013

Don provided the numbers a while back, a search should find it.

restart · Jul 23, 2013

here ya be, its on this page

http://e9coupe.com/forum/showthread.php?t=13041&highlight=fan+clutch+number&page=2

30csl · Sep 9, 2014

Well guys, a little embarassing to bring up this old thread as it shows how long its taking me to put the bat back on the road. I revisited the 9 blade fan lack of clearance today and it looks like the whole engine is 1/4 - 1/2 inch further forward in the engine bay than on my other car which has the 9 blade fan installed. Now knowing that the engine and gearbox have three mounting points and none of these looks 'stressed' forward I'm very doubtful I will 'find' this room. I am guessing the subframe is bolted to the body with no adjustment forward or backwards! Anyone found this much room by jacking up the engine and moving it backwards?

sfdon · Sep 9, 2014

Old motor mounts?

30csl · Sep 9, 2014

No Don, they are new and look pretty right. I may change them out to see if it changes things. The car hasn't been driven yet so needs to settle down.

9 blade fan conversion

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