Hot Rod Forum banner
1 - 3 of 3 Posts

·
Registered
34 Ford, 502 BBC 6 speed Tremec
Joined
·
120 Posts
Discussion Starter · #1 ·
I have a ZZ 502 purchased with the Serpentine accessory kit which came with the GM R 4 compressor. I wanted to upgrade the compressor to a Sanden 508, but the only conversion kits made were for SB Chevys. I bought one any way and they were right they don't work. The reason is that my motor was equipped with a massive cast iron rear mount for the R4. which also holds the idler and tensioner. If you have the same set up and want to do the conversion, this is what I did.


But If you are looking for show car quality this will be a little crude for you, if you don't need the Billet Aluminum look it may be just fine.


This was all done with a drill, a ball peen hammer and a 90 degree Dewalt 4.5 inch grinder/cutter.


I realized the Bolt patterns for the 2 compressors are almost identical.


I first labeled all the holes to avoid confusion.


Then matched up the front stamped steel mount to the Sanden which needed just a little grinding to clear the smaller bolt heads on the compressor. These 3 bolts are going to be the ones that hold the compressor in place.


Make a templet for the rear bolt pattern and shape of the Sanden, put some tape on the cast iron mount and mark the areas needed to give the clearance needed to make the Sanden drop into the mount. Make your cuts with the Dewalt straight down about 3/8 of inch apart. When done tap back and forth with the hammer and the pieces will break right off. Later you can smooth with the grinder.


Now you have to slot the upper bolt bosses so that the rear ears of the Sanden will fit in place. Again mark and cut with the Dewalt. Here I drilled some small holes crosswise under the cuts and they snapped off easily with the ball peen then smoothed it out with the grinder. You will have to grind away what you need later to get the Sanden to drop in freely.


Last problem was the bottom bolt boss on the mount hitting the last ear of the compressor. I decided not to use it and drilled most of it away with a 3/4 drill bit and grinded the rest away until the compressor dropped into place. Going back up and down to smooth out all the cuts and getting clearance where needed.


I left a lot of inside clearance on the ears that were just created with a gap to be careful not to break them off. I cleaned out the threads and drilled out the holes on the back side, now running the bolts from back to front. Knowing that my cuts weren't perfect and not wanting to tighten these bolts to hear the ears snap off I used Locktite and feel that the compressor would be safe resting on these 2 rear bolts with the 3 on the front stamped steel mount holding it in place.
If you have precision cutting machinery you may be able to do this differently.
Since the bolt pattern was slightly off, I also drilled the rear mount holes on the compressor about 1/16 inch larger.


Assemble everything together on the bench and then mount to the motor.


You will need an 1 inch longer belt, I also had to change the hose to the condenser. Sanden takes different oil, so change the drier and run a flush through the system. I'm getting low side readings around 10, high side 210 and its cycling off at 40 degrees on at 50 inside the car.
 

Attachments

·
Registered
34 Ford, 502 BBC 6 speed Tremec
Joined
·
120 Posts
Discussion Starter · #3 ·
Chevy bb r4 ac compressor conversion to Sanden508

Thanks Scooting.
I Spent 2 afternoons cutting and grinding, but it was definitely a low cost conversion. Compared to having new mounts custom machined. The conversion kit I sent back was $60 for just 2 brackets, nuts bolts and spacers.
I spent a month looking for parts and some time on the net looking for someone who did the conversion, without any luck. So anybody on our Forum that I could help out, so be it. I get a lot of help from the members here.
 
1 - 3 of 3 Posts
Top