From: Bruce Farrar
Date: Sat, 2 Jun 2001
Subject: RE: A/C 134a Conversion


The Sanden is a 508 rotary, and I bought it because Jim at Mesa said it was the conversion one for our Bav's and also Tom Van Gutten wrote a great article about this conversion saying the 508 and 510 (just a wee bit larger) would fit with the new engine mount that came with the unit.  Tom's article is somewhere in the technical archives of the SSR's web site, I believe.  If you can't find it. I'll email you a copy. 
I had run my rpms up to 1400 or so, just so when it ran it wouldn't pull the engine down, and I find that this was not needed.  So now I have rpms set at 1000 and when a/c on, it drops to around 800, and just a wee bit of hp loss (I guess).  The Behr and also Bosch units are a rotary design that was originally installed on the very late Bav's and early 530s, whereas most of the early Bav population had the York piston compressor installed along with a muffler near the dryer.  The Sanden and Behr units don't need the muffler.
Hayden's web site has all the details and measurements for their fans, and alot of other goodies.  The only unit of theirs that would fit thru the front grill was the 10" thin line # 3670 unit.  The 12" #3680 will fit too, but the only way to get it on is to remove both the rediator and condensor.  I would like to use their 14" #3690 one, but I don't see how I can squeeze it in without some serious sheet metal reconfiguration.  If you can't find their web site, let me know as I downloaded their Cooling Products Catalog in PDF format and have all the numbers.  Guess I could email it to you too....let me know. or
Woke up this am to find another leak...I'm plagued with these, but it comes with the territory.
The Sanden 508 unit is briefly described in Sanden's web site under "Converting R-12 systems to 134a" or some such notation.
What Sanden did you use and why.  I looked at their website and uncovered 5 & 7 piston types.
But I think, that the shitty York was a piston and the Bosch that I presently have out of the car on on my work bench is a rotary design.
Can you advise also if when you turn on the compressor, does it suck much hp?