AC Pulley?

[ProctorSilex]

Is the pulley behind the fan for an air conditioner? I did not notice any mounts or other indications of a compressor ever having been there. I did not find any info about it anywhere online.
The AC pictures here show a similar pulley. Closest I could find.

[Marc]

There are subtle variations depending upon manufacturer (none of the A/C parts are built by VW) but essentially they're all like this:


The mounting bracketry for the compressor also varies, but generally they're made to pick up some existing hardware points and once removed might leave few traces. Here's a homemade A/C installation (with an additional alternator, too) on a Bus w/Type IV motor: http://motorheads.net/vw/DCP_5495.JPG

Here's a typical installation on a 912E: http://i.ebayimg.com/images/g/c5EAAOSwB ... -l1600.jpg

[Piledriver]

Actually on most T4 installs on vehicles made for T4s with stock cooling(411/412/914/Busses) (or T4s in T3s for that matter) the compressor bracket bolts to the side of the fan housing, which is reinforced for that purpose.

If you look in the type3 forum I documented my AC install pretty thoroughly, used a Vanagon fan housing and modded the original York bracketry to use a moden Delphi variable displacement compressor.
I'm using a serp belt and a modded Ford PS pulley on the crank.

[ProctorSilex]

Thanks, guys. Maybe the pulley will come in handy some day.

[Piledriver]

I just realized never answered the original question fully,:
Yes, the AC pulley for std T4s is behind the fan, and the compressor turns backwards.

Any piston type compressor I am aware of should have no issues running backwards, as they are poppet check valve units, so in/out are still in and out, as long as the old bearings/seals don't care.
The rotary vane type cannot run backwards.(kinda rare anyway)
The tension straps in the clutch look like they should care but apparently don't.
You can actually get reverse rotation clutches for some compressors, but the original Youks were "wrong" and the Delphi in the square is wrong as well, works fine.

FWIW, I believe the pulley/support setup Marc shows was originally for the AIR pump on California cars and maybe late federal. The pulley's a bit small for AC.

[Marc]

FWIW, I believe the pulley/support setup Marc shows was originally for the AIR pump on California cars and maybe late federal. The pulley's a bit small for AC.

I had a 912E with the smog pump and a stock (small) pulley there - when the A/C is added to those cars they get a second pulley alongside that one, as shown in my initial response: http://i.ebayimg.com/images/g/c5EAAOSwB ... -l1600.jpg
It's not a very large pulley, about the same size as the one that gets added to a Type I for A/C like this: http://images.thesamba.com/vw/classifie ... 632790.jpg


Took a while, but I finally found some pictures of the other setup that sandwiches a (~4" dia, 60°) pulley between the fan and the hub and drives the compressor "backwards": http://images.thesamba.com/vw/gallery/pix/1457048.jpg
http://images.thesamba.com/vw/gallery/pix/1457051.jpg

[Piledriver]

Interesting, so I assume there's no room in a 911/912 chassis in the "normal" T4 compressor location on the 3/4 side of the fan housing?

[Marc]

Pretty crowded on the LH side, and I think the rear hanger would prevent locating the compressor there even if you had no qualms about whacking the body up.
69BahamaYellow at T.O.S. grafted in a Denso 10PA17C scrounged from a `98 Mazda MPV, then modified a power steering pulley from a `90s Honda to go in place of the vee pulley - that allows use of a 4-rib multigroove belt that should be able to transmit more power, and it's a little larger in diameter. Made his own mount and tensioner setup, too - pretty cool. See pages 3,4,5: http://www.thesamba.com/vw/forum/viewtopic.php?t=630832

[Piledriver]

Nice thread, but he spent an awful lot of $$$... I have ~$800 in my setup ---including a ~full tooling up do my own AC work.(via Ebay and Craigslist)
Admittedly he probably paid big $$ for the rareish old Bus overhead AC parts.
I'm about even with his cost if I include the used Miller Synchrowave 250 ...

I never found a need for an idler with the serp belt, but will pick up a couple of those Honda pulleys, might have a better offset than the one I used, which is a 6 rib (I only use 4 rib belt, width issues, even with a T1 oil cooler).

The crimper setup cost less than I was quoted by local shops for the service on one custom install, and I was able to do all of the crimps in place on the car in about an hour, while installing hose.(negotiated a good price, the shops didn't want to negotiate anything, so they lost completely)

The AC in the car itself has ~$350 into it, and I have a mile of extra hose, and figured out where to buy it cheap...

I should be able to run most of the lines in the 914 with what I have left over.

One thing to note is that with modern parallel flow/micro channel condenser designs, a condenser the same physical size as an old serpentine tube and fin unit can have 3-4x the capacity in some cases, typically 2-3X.
Proper ducting/keeping the hot and cold air side apart makes all the difference.(Just like an aircooled engine)