Hi, working on getting the AC fixed in my 92 Z28 with a 5.3 swap, but not sure what orifice tube to use. I am using a Kwik Performance bracket and Sanden SD7H15 compressor, the rest of the system is stock third gen. In the FAQ on converting to R134a, it says to use the Ford red orifice tube as it's better suited to a R134a in the third gen system. Does that hold true for my situation as well?

From what I can find, the stock orifice tube is white, which is larger than the red tube. Then there's a blue tube, which is even smaller than the red. I've also heard you can get an adjustable orifice tube at the parts store. Any recommendations?

 

I don't have an answer for you, though I am interested in such an answer. I've got a question. Do you have the Kwik Performance bracket and the compressor mounted up along with your radiator overflow tank? If so, how is the fitment? Would love to see a picture if you have one.

 

https://kansascity.craigslist.org/pt...747385609.html

 

The OT couldn't care less about LS swap, Sanden, or any of that. A compressor is just a pump, and the engine merely drives it. All it cares is, maintaining the pressure differential across it, at its design value. It is no more concerned about that other stuff than your bathroom faucet is about the brand of pump at the water works or the kind of engine or motor powering it.

The Frod orange or red OTs are indeed the best to use. They match the properties of R-134A in a GM R-12 system the most closely. The stock white one is much less suitable. Nearly everyone I know, including myself, has had poor performance from it, in that configuration.

I would not recommend an adjustable one.

I have never used a blue one, but one other user on here has. He also seems to feel that it was less suited than the others.

 

Good info, thanks for confirming sofakingdom. The red tube it is, then. I wasn't sure if the compressor would matter, as it's slightly larger displacement than the stock third gen or LS1 compressors. I totally get that the LS swap doesn't matter; the AC doesn't care how the pulley gets turned as long as it's turning

3.1EyeCandy, yep I have the compressor mounted, working on plumbing it to the drier and condenser. When the car was LS swapped they used an aluminum overflow tank mounted on the fender, there is plenty of clearance but I don't know how it would look with a stock overflow tank.