A/C question

[NOSed69]

I am starting on a new project truck and have a couple things still up in the air. I am using an air cab 72 that has had the a/c evaporator open for a LONG time. Whats everyones opinion of the POA valve?? I have no expeiernce with them and dont know how they operate? I see in searching here the Oldairproducts.com has POA conversions, but they also offer a new evaporator that accepts an orifice tube?? Since I'm building a system from scratch only starting with the original evaporator( assuming it pressure checks ok) What parts should I use? BTW, work in auto/heavy truck parts, so sourcing pieces isnt a problem. Just not sure what parts will work the best together!

[NOSed69]

Still looking for some advice on this. Anyone have anything to say??

[leddzepp]

If you are starting from scratch, I would go with a complete kit from vintage air.
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[ERASER5]

Without a doubt, I would change over to a orifice tube/ accumulator and cycle the clutch. Tune the low pressure cut out switch to about 20 psi and you will freeze ice cream. If I recall, Old Air can set you up with all the replacement parts to make a completely new system.

[Andy4639]

I used Chevy junkyard parts out of a later 90's truck inside the 71 Chevy factory boxes. I have the 134A Freon and with the cowl vent mod my AC blows 38 degree's all the time now. The orfice is the best way to do it.
After the junkyard parts I did buy new condensor and compressor for 134A though. The factory stuff just didn't hold up. The old A-6 compressor want last long cycling are at least mine didn't and I bought a new one for it.
I hooked the electric fan to come on when the ac switch is activated by way of a 30amp relay.

[mrein3]

Originally Posted by NOSed69

I am starting on a new project truck and have a couple things still up in the air. I am using an air cab 72 that has had the a/c evaporator open for a LONG time. Whats everyones opinion of the POA valve?? I have no expeiernce with them and dont know how they operate? I see in searching here the Oldairproducts.com has POA conversions, but they also offer a new evaporator that accepts an orifice tube?? Since I'm building a system from scratch only starting with the original evaporator( assuming it pressure checks ok) What parts should I use? BTW, work in auto/heavy truck parts, so sourcing pieces isnt a problem. Just not sure what parts will work the best together!

With all due respect to those that chose to go a different way, there is nothing wrong with the stock POA system. I have two stock systems (my Chevelles) that have been working since GM delivered the cars in 1971 and 1972. I bought a stock POA off a junk truck in about the year 2000. I have no idea how long that system was open but it was open when I got to it. I bolted it on my truck in about 2006. I completed the AC project two years ago and it works perfect.

A6 compressors are not designed to cycle on and off. If you run one (stock compressor), don't run a cycling AC system.

You can adjust the POA to work with R134a or leave it and run R12. The link I used to adjust it is broke. Perhaps you could search around on ackit's website to see if it has just been moved or something.

I did a write up here a while ago:
http://67-72chevytrucks.com/vboard/s...d.php?t=478564