Dry Bearings

[smallcox]

Just got me some SKF alternator bearing for my air cooled as the current ones sound F,F,F, DRY and knackered.

The quest must now start to change them, but do I remove the engine from the car or it does look possible to remove the alternator with engine in situ providing I don't drop any parts inside the fan housing. Has anyone got some advise on the subject.

Plus spoke to some helpful guys who can supply pullys in ali for the alternator and belts to suit to slow the fan down. He recons £15 pounds for the pully so may have a go at this soon

[bis13]

you can do it with the engine in the car however you must get into the rear of the fan to undo the nut that secures it in order to remove the alternator so it means either accessing the fan/nut via the air feed opening in the rear of the tinwork or removing the top airfilter gubbins bit of tinwork. its a crappy job as you need some contortionist skills but hey thats the world of fiat 126, also the woodruff key that holds the fan on MUST NOT DROP INTO THE SUMP so make sure you bung it up with a cloth before you start undoing stuff. one question is why do you wish to slow the fan down as the normal replacement pulleys fasten the fan up surely that is what you want?   

[1973/126]

 I tried it with the tin work in place, but never managed to do it for some reason..., but as Mick says it`s possible. I just drop something in there, or couldn't get the alignment right...
 I normally strip one half of the engine now, but as you say it might take the same time to pull the engine out. The only thing, your engine bay has few more bits and pieces than a standard car
 

[smallcox]

Yes I know I will drop something inside because thats life

Waiting on some Diff bearings so may wait until Wednesday and remove the engine/box to do both jobs.

As for increasing the pulley size on the alternator, I hope this has 2 effects. 1 is to slow the fan down because the engine now runs higher revs than before and that tin fan may just say goodbye like Rustys one did last year. Because the alternator pully is smaller than the engine pulley is must go that at any rev off the engine the fan spins faster so 6000rpm engine may mean 9000rpm tin fan (not good).

2nd by gearing the pulley in this way it will require less effort to turn it. Less effort put into the fan more power left over to push the car along
I know back in the past Kenlowe fans claimed 3bhp was asorbed by the fan and our fans are bigger so makes sense to me as 3bhp is a big portion on our 24bhp power lumps. I also know that the faster the fan spins the less efficent it becomes and not more efficient that you first would quess.

So who agree's with me

[bis13]

idont know its so confusing......

[GTMaster]

It's not just the pulley size that counts, it's how much energy the alternator uses up, e.g. the alt. uses up less power from the engine if you have all the electricals switched off (the alt. only uses up as much power from the engine as it does to charge everything else.) How much more is the engine going to spin faster that you need to 'slow' the fan down? Also enlarging the size of the pulley  might mean that the charge won't be enough if you have extra lights, speakers,radio etc. installed. I think the factory engine can spin at around 5000-6000rpm max. with the original fan...
I made a tool to hold down the dynamo pulley. Behind the nut on the fan side is a locking washer, a cone shaped large washer and a large flat washer (behind the fan if i remember correctly), also need to be careful of the retention pin on the axle...

[Darrell]

Mine runs out of electricity when the idle is set too low so might mean you'll have to set the idle higher.

The Alloy fan is said to be able to handle higher RPM but then there are toothed belt kits about that have equal size pulleys so must have been thought of.

There are two types of toothed belt kits, toothed as in ridges along the length of the belt and toothed as in teeth like a cambelt.

I was looking with lust at the cambelt type option as belt tension needed would be minimal and help those pesky bearings.

If the fan works like a pump, the closed impellor will be more efficient than the open alloy impellor however I doubt it would draw less horsepower.
With pumps we trim the impellor to create less pressure thus the same should be true for the fan on a 126 which would draw less horse power from the engine.
As I see it, with an oil cooler, alloy sump and alloy extended rocker on mine, I should be loosing more heat than original thus should be able to trim the fan, might go alloy if I increase max rpm.
I've comtemplated binning the altenator for a higher output one and placing an electric fan to blow through the barrels and head. Dumb idea? I dunno.

[smallcox]

Dumb together us Darrell,

I thought about electric fan myself, but as a good scientest said to me you dont get something for free. You would have to power the fan therefor the alternator would work harder loading the engine up.

The main reason for fitting the pulley is to slow the fan down was to stop the fan exploding from over revvvvving it. The power saving bit is just a bonus. I also seen the performance shop toothed belt pulleys and yes 1 to 1 ratio but at a price. This is a priceless experiment just costing me for a new longer belt.

To be flash I did think off using a magnetic pully like you find on an air con pump that switches drive on/off so when accelerating you dont turn the drive on, then when upto say 50mph or cruising the drive couples and turns the fan as normal. yes mad i know or is it

ps 1100 revs idle should stop the charging light coming on with 1 to 1 ratio, also my bodywork when moving pulls air into the engine bay

[bis13]

well just to be flash i might have two punkah wallahs in place of my engine fan and on warmer days one serving gin and tonic.... i shall now attend RR dressed as such. i understand the theories and think i too would opt for something a bit more sturdy such as a cast fan in case of it falling apart re rusty.   

[smallcox]

Pulley is made, Tommorow should be able to pick up the longer fan belt

[smallcox]

Well got the fan belt today and removed the old belt just to find out the bearings are really shagged on the alternator.

Thank's Bis13 changed the bearings without removing the engine and did not lose anything down the ducting system

Fitted the bearings and set the new pulley up. At 1100rpm the ingition light just stays out so happy with the gearing, although not quite 1:1 ratio

[eben80]

Hi Smallcox,

I know this is an old post but I wanted to ask:
How did you guys go about changing the bearings in-situ?
Are there bearings at both ends or just the back(bumper)?