I installed a stroked LT1 engine and 4L60E tranny from a 1994 Z28 into my 1981 El Camino. I retained the A/C compressor, radiator & cooling fans, and condenser from the Z28. Everything else in the A/C system is from the 1981 El Camino.

All the information I can find on auto A/C systems says that the (small) high pressure line from the compressor goes to the TOP of the condenser, but the A/C drawing I found on SHBOX.COM shows the compressor discharge line (passenger side port) going to the bottom of the condenser.

The only difference I see between the Elky and Z28 systems is that the Elky uses an orifice tube and accumulator whereas the Z28 used an expansion valve and filter/dryer, which shouldn't make any real difference to the system....right?

A/C theory says that the hot, high pressure gas from the compressor enters the top of the condenser and turns into a high pressure liquid as it cools and exits the bottom of the condenser, then passes through the orifice tube into the evaporator.

Unless GM engineering did something weird in the condenser, I think I should connect the compressor high pressure line (passenger side port) to the top of the condenser?????

 

The small line(high pressure) on my 94 goes to the top of the condenser. That line goes from the condenser to the receiver/drier then to the expansion valve and the evaporator. The large(low pressure) line comes out of the expansion valve to the drivers side of the compressor. Then it goes from the passenger side of the compressor to the bottom of the condenser. The refrigerant flow is from the compressor to the bottom of the condenser, out the top of the condenser to the evaporator.

If you are using the 94 Z28 condenser it looks to me like it will only hook up one way. The line from the compressor goes to the bottom of the condenser and the small line from the top of the condenser goes to the evaporator. In your case you would have an orifice tube in the small line instead of an expansion valve and an accumulator in the large line between the evaporator and the compressor.

 

Thanks for verifying that the SHBOX.COM system diagram is correct and that the A/C system obviously works when connected in this manner.

In the other vehicles I own (one GM and one Mercury), the high pressure line (small line) from the compressor (in our case connected to the passenger side port of the compressor) is connected to the top of the condenser.

As for 'only hooking up one way', I am having to build all of the connecting hoses/lines and the tubing/line/hose sizes GM used in '81 are different than what they used in '94. Before I order a lot of connections/tubing and hoses I wanted to make absolutely sure the refrigerant routing is correct. I guess I'll use the Z28 refrigerant flow path......it obviously works!

Thanks for the help.