A/C system.
This RR had a factory a/c but all I had was the TXV valve and hose and then the hose to the dryer and then the dryer hose to the condenser. So when I rebuilt the 440 I did not have an AC pump. All things considered I was likely going to upgrade to the 134a system. I start googling and find the systems that use the factory evaporator and controls but upgrade the pump and condenser. Like so:
I see an upgraded TXV valve a sanden pump thermostat brackets and hoses.
I hop on eBay and I found a sanden pump with two groove pulleys but the dude said come off of a Camaro and he upgraded to a serpentine system so I bought it on a whim for 60$. You can see in the pictures above in the alternator upgrade section when I was running a carb.
After doing a lot more searching I found four seasons website and I found the factory TXV valve:
I saw that it was 1 1/2 tonne and took note of the hose connections. Then I used their search tools and found the replacement without the equalizer:
next up was the condenser I was just going to buy one but my son was over working on his '96 Dodge pickup and we removed his condenser and while he had it out I took some measurements and voila it's tight but it does fit and it feels most of the radiator opening.
So now that I have the big pieces in place I got online ordered fittings and hoses. Got the hoses sorted out, took him down to Napa and had them crimped and got it all hooked up. Pull the vacuum charged it up fire the engine up and it worked great... At an idle. On a 90° day low side was about 35 high was about 270 PSI the center vent was about 37°. Life was great until I revved the engine passed 1500 RPM. That's when all hell broke loose. Pressures went to 15 when it tripped out and the high side was up to 375 sometimes 400. Let it come back to an idol The pressures would normalize pressure pump would get back on and cool like a champ. Had to scratch my head a long time on this. So I bought another TXv another compressor just like the other one another dryer and still had the same result. And then I gnashed my teeth a lot.
A couple of months later I started doing more research on the pump itself I had purchased two sanden SD5H14 compressors
And for some reason I had to spend 300 bucks to actually look up the pump. Turns out it's a two ton pump. At an idle at an idle The pumping losses were enough that my system responded very well but when I revved it up it was sucking the vapor out of the evaporator and dropping the pressure and over pressurizing the high side.
So the easy fix is a one and a half ton compressor which is a sanden SD509
As you can tell I also made more brackets to convert to a low mount below the alternator. I'm running the same one and a half ton TXV valve and condenser out of a '96 Dodge pickup and a low pressure switch from a late '80s Chevy pickup that is adjustable.
Last summer on 100° day at an idle I was running about 40 to 45 psi on the low side and two 250-260 on the high side. The middle vent temperature was about 45 to 50° driving down the road idle steady state was about 40 to 45°. And I have no carpet or insulation or anything in the cabin. It wasn't cold by any means but it was adequate.