the wanderer

whats wrong in this photo? Hint: Spacer Sleeve?

Is the sleeve / spacer lined up correctly?

Note sleeve angle
This should be a simple DIY right "Changing the V Belts"
Does not always work out correctly sometimes
This is your road side test, havin fun here!
Just completed alternator re-install. I think I will edit alternator removal thread to include re-install.
Heres the belt install quiz
Join Me

So if you car is occasionally burning off the alternator or fan belt
Are these parts installed / alligned correctly?
In other words are they in the correct order and allignment ?
See pics
TJ

Cactus

Clewett Pulley Kit

Mr.Woolery

Beat me to this answer, LOL

pp000830

Hi Wanderer,
How to make belts last and run quietly involves
-- Using the correct belts,
--Having the factory pulley update installed,
--Using the Porsche published belt adjustment process,
--Use a Gates belt tensioning gauge when installing and adjusting the belts.
- Checking the belt tension once the belts are well seated and bedded after a belt change.
Doing the above and the belts will have a reasonably long service life.
Here is a page that discusses installing belts:
https://993servicerepair.blogspot.co...fan-belts.html
Andy

pp000830

Hi Cactus,
The Clewett kit is not the answer for some:
https://993servicerepair.blogspot.co...fan-belts.html
Andy

95_993

+993 very happy with my Clewett set up!

EckFe1

Me too, best mod to stop worrying about all the above issues.

71-3.0-911

Honestly though, the dual belt system isn't overly complicated, it feels like the forum makes it seem so. Attaching and adjusting the belts should be simple. I always removed spacers until I no longer heard the belt squeal or slip. Never broke one, never had an issue with wear, etc. never used a gauge. Never had a problem.

Now, that being said, I put in a Clewett and haven't bothered with any of the belts any longer.

the wanderer

I am pleased the fellows who answered to date all are happy to spend on Clewett.
this is 0r was intended as a quiz...a roadside question
How to install a Belt? Properly
?
What's right or wrong with pics?

71-3.0-911

Just need the correct Allen wrench and a bit of patience or...

Cactus

I saw what was involved with the stock pulley/belt installation and didn't want to deal with that on the side of the road somewhere. I am leaving on a 600 mile weekend trip in the mountains tomorrow morning (probably all in the rain) and I know the belts are not going to implode so this makes me happy.

TDW993

I just went with the RS single belt set up. Works perfectly. I love the Clewett set up but just wanted to keep it a bit more stock looking.

ClassicAndy

im a bit unsure of the actual request by tthe OP, but I’ll go ahead and address the belt burning issue:

Please confirm you have the pully update on your fan?
if not, id say that is your main reason why you are burning off belts.

BTDT myself and all it required was the pulley update / larger diameter pulleyes and the beltburning stopped.

Porsche part number for the updated dim pulley is 993.106.268.01

Still unsure? Then I’d recomend you to read more here: https://rennlist.com/forums/993-foru...or-pulley.html

Cheers,
Andy
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Jlaa

Agreed. Just get the updated pulley.



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Jonny Retrofit

Ok, I'll chime in here. As we develop high output alternators, we always pay close attention to the belt temperature and slip. Although we recommend a serpentine for running our units at high loads, I did want to find out what causes the alternator belt on the double belt setup to fail. The short answer is heat and belt speed.

These tests were done with a high output unit producing 80 - 90A. When the car is driven, the engine fan serves to cool the belts and even with a high load you will rarely see the belt temperature above 70 deg C (measured with an IR gun). When you stop, however, the temperature in the engine bay rises and the cooling effect is less so the belt temp climbs. The belts are good for about 80 deg C but in traffic, on a summers day, after a fast run I have seen over 100 deg C which is beyond the temperature rating of the belt. Now, in this condition the worst thing you can do is switch the car off. When you do that the hot belt will take a 'set' to the pulleys - if you take it off the next day you will find it is no longer round but egg shaped like the pulleys. So, you start the car, the battery demands some charge and the belt shreds itself in the first few minutes of the drive.

We converted over to the Turbo pulleys and they are 'better' but still we shredded the alternator belt eventually so I started to look into this a bit closer as we never have belt issues with older 911's running the single belt. The problem is that the 993/964 pulley drive ratio is something like 2.6 times the crank speed whereas the 911 is only 1.8. This seems ridiculously high and puts a lot strain on the belt as 1) it is turning fast and 2) it has minimal contact area around the small circumference . What to do?

I noticed that for some reason the recommended size alternator belt rides very low in the pulley compared to the fan belt. Just look at Jlaa's picture above. Why is the belt so low in the pulley? They all seem to do this (even with the correct length Porsche belt) - it doesn't seem right.

I ended up buying a Gates belt that is 3mm longer than standard. With this belt, when shimmed, it sits in the top of the pulley (like the fan belt does). This gives the belt more contact area around the circumference and also slows the alternator down. No problems so far.

I'll post some pictures and belt details when I get a minute.