Hi everyone.

I've bought a new aluminium cooling fan which is next on the list to be installed. It seems that I need to re-use some of the central parts of the old fan that attach to the back of the generator.

What's the drill for getting these off the old fan? Looks like it's not just a simple tap with a hammer.

Tim

Although it's about the dynamo removal; might be some help here Tim.
https://www.fiatforum.com/500-classic/306785-dynamo-brushes.html

Thanks Peter, doesn't go into detail about the fan, unless I missed it.

There seems to be a tab or notch on the central part of the fan that fits over the end of the generator. This acts as a lock, locking the parts in place that fit around the generator end. Photos attached. There's gotta be a technique or tool or force that is used to open this up.

...I'm thinking...?

Tim

I think I figured it out.

The tab doesn't lock the central part on as tightly as I expected. A bit of fiddly with a screwdriver and pliers and they came apart.

Fan upgrade in process. :slayer:

Tim

Main thing Tim, check that the new fan doesn't catch on the cowling when re-assembled. You don't want to fit and then have to remove the engine again. Apparently the idea is to use shim washers either side of the impeller where needed to provide clearance.

Yes, thanks Peter. I'm on to that.

What is more of a problem is that the new aluminium fan is made of thicker material than the original. Once the central parts are in place and the fan is on, it doesn't leave enough on the shaft to get the nut on.

Have emailed Franco at Ricambio for suggestions. Any thoughts?

Tim

Tim, I guess that if there were any spacers, these may not now be needed, although I would think you still need the conical washers that grip the impeller.
You probably can't grind away any of the aluminium because it will need to be chunky for strength.
Tough one that; I'm sure Ricambio will have a solution.

I fitted the alloy fan and it came with a large dished washer that compressed against the fan.

Wow, thst looks chunky! So that washer was flatter before you tightened it?

You have got me digging out bits now but no problem as I had another fan in my cupboard. Out of interest I weighed the alloy fan and an original steel one and the alloy fan is just 15 grams lighter. However when I first ventured into tuning I was unaware of the limitations of the original fan and I had one let go at about 6,500 rpm which meant with the standard fan belt drive the fan would have been close to 10,000 rpm. Parts of the fan actually pierced the steel cooling housing panels. The steel washer is actually dished like a core plug then flattens when tightened against the driving boss flange. For balancing purposes I did a little fettling as the castings are not perfect but I am running one at the moment and they seem to perform ok. There is another type of fan around but they seem quite rare. They have a steel core with a high density plastic fan cast on.

Hi Toshi

That's helpful, thanks for the pictures.
What I was doing wrong was trying to use the old domed centre spacer. I forgot there was a new one that's not so domed, that came with the fan. :bang:

Seems to fit ok now.

Tim

Toshi 975 said:

I fitted the alloy fan and it came with a large dished washer that compressed against the fan.View attachment 147876

Click to expand...

Toshi 975, did you torque the securing nut and if so, was it to the same spec. as with the original impeller?

I have one now; they're a nice item but a pity, being deep inside the housing, they are never seen in action.

Stupid thing is, the standard one is behaving itself now and not coming loose.:bang:

fiat500 said:

Toshi 975, did you torque the securing nut and if so, was it to the same spec. as with the original impeller?

I have one now; they're a nice item but a pity, being deep inside the housing, they are never seen in action.

Stupid thing is, the standard one is behaving itself now and not coming loose.:bang:

Click to expand...

I have never used a torque wrench on any fan, just do it by feel

Toshi 975 said:

I have never used a torque wrench on any fan, just do it by feel

Click to expand...

Have you had any overheating problem since fitting the aluminium fan?

My car seems hotter than it used to be. Engine lid handle very hot to touch...

None that I noticed. Biggest cause of overheating I had was setting the mixture too weak

1500500 said:

Have you had any overheating problem since fitting the aluminium fan?

My car seems hotter than it used to be. Engine lid handle very hot to touch...

Click to expand...

I had second thoughts on that aluminium fan and since tightening without a torque-wrench it hasn't come loose. It as since flown off to pasture new...not to far from this posting.

Something's not right if the handle is as hot as that, although saying that, it must get very hot at times even here in Scotland because the paint on the exhaiust side of the lid is full of micro-crazing.

Following as I have an aluminium fan on its way from David. Notice the comment about a different domed washer. Can anyone explain the difference? I won’t have an alternative washer as the fan I not from new. Ta