Really dumb pulley question

[mr911er]

Hi guys
Just replacing the alternator pulley on my 82 sc. The previous pulley disintegrated....



So I sourced an identical pulley, got the fan boss welded (as advised in here) and have reinstalled;



So Im now wondering if the pulley arrangement is wrong, and maybe thats why it failed in the first place, but cant really work out how it should go together. The car originally had an air pump, but this has been removed. Im thinking that maybe I should get the
single pulley...
I cant see in theory why a double pulley with one belt should be a problem...
Anyway, I would welcome any comments on the arrangement in place

Cheers
Kevin...

[theiceman]

I have a 78 sc and have had a double pulley for eons , absolutely no issue . I considered going to the single for looks only but never bothered.

I didn't think the 82s had an air pump. I thought they had gone to the lambda sensor by then and did away with it , you learn something every day

[GaryR]

It's hard to get the pulley alignment wrong if the fan housing is seated correctly, while there is absolutely no issue using the two belt pulley I would put a single in for aesthetics (and it weighs less too!)

[Craig_D]

I've got a '78 running the double pulley with the single belt and haven't had any issues.

I, unfortunately, have to re-install the air pump every single year to pass emissions (which sucks given that the air pump isn't really connected, it just looks like it is, and I pass).

[mr911er]

Im still confused about this bloody pulley, and its driving me dememneted...������
Does the 'double pulley' consist of the standard half pulley AND the larger pulley that was fitted to my car i.e. are two pulleys (or half pulleys) fitted. My car was fitted with one part - which I think should have been fitted with a second half pulley. But I cant find any diagram/photo/ thread that supports this.....!

[Targalid]

Yes. The inner half pulley mates with the half pulley which is the fan hub. The shims determine the distance between the halves and thus the tension on the belt. The air pump pulley is outside that half pulley and drives the air pump belt. There is not a separate fan belt pulley, just the two halves described. If you have AC drive belt then there would be another pulley as part of that system.

[Rawknees'Turbo]

Originally Posted by mr911er

So Im now wondering if the pulley arrangement is wrong, and maybe thats why it failed in the first place, but cant really work out how it should go together. The car originally had an air pump, but this has been removed. Im thinking that maybe I should get the
single pulley...
I cant see in theory why a double pulley with one belt should be a problem...
Anyway, I would welcome any comments on the arrangement in place

Cheers
Kevin...

In the above picture, it looks like you are using the smog pump groove on the fan pulley as the drive grove for the fan (from the crankshaft), and if so, that is incorrect. The actual fan pulley groove (talking about the groove that is "made" by the fan hub itself and the outer pulley half) is what the crankshaft pulley & belt should be connected to.

[mr911er]

Ok, that makes sense, but surely the widest groove possible is the width of 6 shilms - is that enough?
Giess I will have to have a play with he car tomorrow and see if it works!
Thanks guys, much appreciated...