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View Full Version : Any one ever convert a Chevelle from POA valve to orifice



gmachala404
10-20-2011, 08:40 PM
I have gotten to the point on my LS3 Chevelle project to start on the A/C and noticed the car has a POA valve eliminator kit on it and a new POA valve will cost $250.00 ouch! Been reading that an R134 conversion works better and is more reliable with an orifice/accumulator setup. I have a few of these type of evap coils from older late 70s model GM cars at my parents house (800 miles away) and was curious if they would work in my Chevelles A/C box. I pulled the old evap coil out today. Anyone do this before? Any ideas what make/model orifice/accumulator style evap coils would work?

quarterbooty
10-22-2011, 02:57 PM
Why not just calibrate the POA valve for R134a? You can reduce the set pressure to optimize performance with R134a. Here's a link (http://www.autoacforum.com/messageview.cfm?catid=20&threadid=7567) if you want to try it yourself. Classic Auto Air offers a POA recalibration service if you don't want to mess with it.

gmachala404
10-22-2011, 08:24 PM
I don't have a POA valve and a replacement is 250 dollars. I already have an evaporator that will work that is from a
85 Chevy pickup and it fits in the A/C box and is designed for an orifice. I also got a 95 Chevy pickup condensor mounted
in the car now too. These were parts I already had. I am committed to making this work now. Trying to hunt down some
diagrams for the 95 model Chevy pickups to find out where the low and high side switches go. I am pretty sure the cluth cycle
switch goes on the accumulator and is AC Delco PN 15-2832 purple for R134. Now I need to figure out if the high pressure
cut off does indeed go on the bung on the condenser. I think it does but not sure.

Twentyover
10-23-2011, 06:59 AM
......... Now I need to figure out if the high pressure
cut off does indeed go on the bung on the condenser. I think it does but not sure.

Anywhere between the compressor discharge port and the OT or TXV.

supercool
10-23-2011, 07:46 AM
You didn't say which Compressor you were using. If its a late model GM designed for Clutch cycle Operation, this is an easy change over. Measure up your evaporator; Body H,W & Thickness. Distance between tubes. And angle of Suction tube. Find a Orifice style Evap.that fits. Choose an Accumulator that has Ports that work for both Hosing and Switch/Charging port access. I would Strongly Recommend using a modern hi eff Condenser in place of the Factory GM. Use a Blue Ford Orifice/ has double Orings for a positive seal and works in large body Evaps use in all early CCOT systems.

vintageracer
10-23-2011, 08:55 AM
Call Old Air Products in Ft. Worth Texas. They have a POA valve eliminator kit for around a $100.00. It is a simple aluminum tube with a port for 134A compressor cycle switch and a 134 low side intake valve that replaces the factory POA valve. I used this product numerous times on many GM A body Chevelles and it works great with a stock GM system. Instead of regulating the pressure mechanically you now cycle the compressor via pressure monitoring as you do in a modern car A/C system. Works with GM A6 compressors and modern compressors. You use all the stock stuff in the dash and the stock evaporator. This is a BOLT ON modification that works great!

For the best performance replace all your old rubber A/C hoses and spring for a modern condenser that is designed for 134A to get the best cooling.

Works great and will FREEZE you A$$ out of the car!

gmachala404
10-23-2011, 08:39 PM
I almost have to use a Sanden style compressor leaning toward the SD7H15 or SD5H14. With the LS3 engine Kwik makes a bracket to adapt the Sanden to the upper-passenger side of the car (which is the only place I have any space to mount it). I have the condenser in which is very large and made for R134 that fits
a 95 Chevy C1500 pickup truck. The condenser has an orifice in it already too. The evaporator and accumulator are for an 85 Chevy pickup with R134 conversion and they fit like glove in factory box. I got everything wired up now so that the clutch cycle switch and the high pressure switch cut the relay to the A/C clutch and turn on the electric fan relay when A/C clutch engages. The only thing left is to get some hoses and the compressor. So far this swap has cost me nothing since I had the evaporator and condenser already from other parts cars. I know they don't leak I evacuated them quite awhile ago when I stored them and they still have a vacuum. Thanks for the help.

gmachala404
10-29-2011, 03:52 PM
Here are some pictures of what I got done so far with the A/C orifice conversion:
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