AC for a 1971 Scamp

[GottaBeCold88]

Hi folks, I have a 71 Plymouth Scamp that was originally an AC car with slant six motor. The motor is now replaced with a 5.9 v8 from a 2000 Dodge Dakota. I want to use the more modern compressor and serpentine belt drive system on the 2000 motor.

I’m making all new hoses and plan to use a parallel flow condenser. I plan to reuse the underhood hard lines as well as the evaporator. Those will be thoroughly flushed, of course. Plus a new drier and expansion valve.

I plan to use the original refrigerant from 71. I have a lot of old cans of it laying around and I want the Scamp to be as cold as it was in 1971.

The compressor is new. I should replace the oil with mineral oil. Any idea how much? Also, any idea how much 1971 refrigerant I should use? The drier does have the glass viewport. Any other tips or special considerations for this build? Thanks in advance.

[JohnHere]

Back in the days when the Dakota used R-12 refrigerant (1993 and earlier), the specs I have for that vehicle are 40 ounces net weight (2.5 pounds) of R-12, and 7.5 fluid ounces of Mineral Oil. I don't have any specs for the 1971 Scamp with the Slant Six.

With that being said, I'm not an A/C system designer, and I can't say whether R-12 will work at all in a compressor designed specifically for R-134a (the 2000 Dakota). Typically, the process is reversed in that a system originally designed for R-12 (your '71 Scamp) is converted to R-134a, not vice versa.