CFC12 to HFC134a AC compressor conversions

[sstallings]

Guys,

I've found a number of great threads on this topic, some very well documented with specs and pictures using the Vintage Air AC systems. I've used Vintage Air systems on my El Camino and on my street rod so that is the way I plan to go on my V8Z as well.

 

That being said, I'm installing a '90 Firebird 350 TPI engine which has it's existing AC Delco compressor which will be easier to keep if I can get away with it. The tech guys at Vintage Air tell me it can be used, but I can't find any web sites anywhere (so far) that have rebuild kits with new seals for this pump. What I have found are a number of sites warning me that these pumps are prone to leaking even with the old CFC12.

 

So, if anyone has already been down this path, am I better off modifying my AC bracketry to fit a Sanden 508 compressor on my TPI motor, or should I stick with the AC Delco compressor and rebuild it for HFC134a? If I have to go to a Sanden 508, are there brackets available, or am I going to have to get creative with the plasma cutter and welder?

 

Your expereince will probably save me a lot of work and mistakes.

Thanks again,

Steve

[Mike kZ]

Auto Zone has rebuilt compressors, maybe they have kits also:

http://www.autozone.com/R,APP174050/vehicleId,1023902/initialAction,partProductDetail/store,90/partType,00082/shopping/partProductDetail.htm

[getZ]

The sanden 508 is a much smaller unit than the old AC Delco part and my biggest concern with my setup was getting it fit under the hood. I've seen a couple of places to mount them.

 

Mike's got his above the engine (not sure this would work with a TPI intake. Pete's got his on the left side of the engine with a custom fabricated mount. I have that same setup, but it is a tight fit on that side and when the belt start to stretch a little I run of adjustment.

 

I was starting to look into a shorter compressor like the ones run on the vintage air front runner systems. It would keep my compressor away from the exhaust but I would still have the same problems running out of adjustment travel as the belt stretches.

 

I may opt to go for a serpentine system one of these days, they're just expensive. You might look at the Lt-1 guys setup, but I don't believe it is adaptable to the tpi motor. Then again it may just depend on how much work you want to do to get it to fit. I'm pretty sure vintage air makes a water pump that works going in the opposite counter clockwise.

[strotter]

I got tired of dealing with old R4's (I've been fighting them for years), so decided to mount the new Sanden (for a Vintage Air install) on the existing aluminum (late 80's early 90's) serpentine brackets. Turned out to be fairly simple, though I *did* end up doing a tiny bit of welding. Turned out pretty good. From the front:

 

 

From the side:

 

 

The way it worked, was, I got some steel tubing (3/8"?) from Lowes, and welded the little tabs that go from the long "inboard" bolt to the compressor. Literally took 10 seconds, it'd probably cost $5.00 for a shop to do it for you. The tubing takes the compression from snugging the nut onto the inboard bolt. The lower bolt is just snugged down with a pair of interference nuts, no support sleeve. Rock solid and quite easy. Plenty of hood clearance, but I had to get a little longer belt. Any questions email me.

[sstallings]

Mike kZ and strotter,

Thanks for the great tips on either living with the R4 or converting to the Sanden 508. One of those will definitely solve my problems.

 

getZ,

I also talked to Vintage Air about their smaller Sanden pump on the front runner system. Before you go that route, talk to their tech support. The smaller capacity of that pump has to be matched to the rest of the pulley sizes in the front runner system or you will have disappointing cooling capacity. On my next conversion of my '72 240Z I plan to use their whole front runner kit for an LS1 swap. But for now, my son and I are learning the ropes on his '77 280Z with a '90 TPI swap, and trying to do it right while keeping it low budget (at least as much as possible).

 

I appreciate all the good advice. Thanks.

Steve