A/C Question.

[uncle]

Hopefully I can say this so someone can understand it. Is it possible to run a receiver dryer set up on a 67–72 truck and leave the air conditioning on the passenger side? I am referring to the set up that started sometime I’m guessing 73. I know that the rubber lines will have to be modified on the end or on one end. Has anyone ever done this and is it possible. I am asking this because I thought I remembered seeing one years ago but I can’t search the board anymore for some reason. Thanks in advance .

[uncle]

Someone did it on this truck, but the guy that is building it back and wants to leave it on the passenger side. I know this looks like some rigged up nonsense and I have not seen it in person. I know this line is not supposed to run on the cowl. But again, is this a possible set up?

[RustyPile]

That's the liquid line. It runs from the condenser to the evaporator. It also contains a fixed orifice instead of an expansion valve.. If you look closely, In the picture, that line is just looped up along the cowl and isn't connected to anything.. In a normal POA system in the years of our trucks, the compressor runs continuously when the AC is on and the dryer is in the high pressure stream. In the system you're proposing, the compressor is cycled off and on by a pressure switch located in the dryer/accumulator which is in the compressor suction stream.. An evaporator fitted for the cycling clutch type must be used along with the other proper "plumbing".. One thing I might add to this.. It's not a good idea to use the factory A-6 compressor.. It's designed to run continuously and doesn't tolerate being cycled off and on.. .

[D.B]

Is this what you are asking about. This is my 72 C20 Big Block.

[uncle]

That helps. I’m assuming yours is not a cycling setup?

[clay68c10]

The square body evaporator is what you want. It is slightly smaller than the 67-72 so you will have a small gap to fill inside the case.
Get the matching accumulator and a generic fit parallel flow condenser from eBay or wherever and enjoy the cold.

[D.B]

Originally Posted by uncle

That helps. I’m assuming yours is not a cycling setup?

Yes, mine cycles and the compressor is designed to work with this switch. The cycling switch is circled below in red. The system is R134A and uses a large condenser which I made a cover plate to go between the condenser and core support. I was told to get the condenser as close to the radiator as possible without touching it. The condenser is slightly larger than the opening, so the plate blocks off any open spaces between the core support and condenser. So, it forces the radiator to pull air through condenser.

[Bob B.]

Originally Posted by D.B

Yes, mine cycles and the compressor is designed to work with this switch. The cycling switch is circled below in red. The system is R134A and uses a large condenser which I made a cover plate to go between the condenser and core support. I was told to get the condenser as close to the radiator as possible without touching it. The condenser is slightly larger than the opening, so the plate blocks off any open spaces between the core support and condenser. So, it forces the radiator to pull air through condenser.


Attachment 2280404

If you want a cycling system, this is the way to do it. Is that a Pro 6TEN compressor? I used one on my friend's '72 El Camino with an expansion valve and it also works well in a non-cycling system.

RustyPile mentioned that a Fridgidaire A6 compressor was not designed to work in a cycling system. It's true, GM figured that one out the hard way back in the late 70's.

[D.B]

Originally Posted by Bob B.

If you want a cycling system, this is the way to do it. Is that a Pro 6TEN compressor? I used one on my friend's '72 El Camino with an expansion valve and it also works well in a non-cycling system.

RustyPile mentioned that a Fridgidaire A6 compressor was not designed to work in a cycling system. It's true, GM figured that one out the hard way back in the late 70's.

Bob B - Yes, you are correct, it is a Pro 6TEN compressor. I wanted to keep the factory look as close as possible. I know I give up room in the engine compartment and that this system is not the most efficient compared to the aftermarket setups. But it does look OE factory to the most part and I also liked using the OE brackets. On a normal day (outside low 90's) the vent temp is low 40's and a hot day (outside low 100's) the vent temp is mid 40's.
I am sure if I tinted the windows the hot day temps may drop a few more degrees.

[uncle]

Thanks for the help. I think this will get my buddy on the right track.