forvicjr

So my 81 is a factory non functioning system at the moment. I have plans to get it going with a few changes. I do know the r12 components aren't the best for 134 so with that being said my plans are as follows, please inform me if this is a bad idea or what i might run into in the process. First replace the evaporator with a 134 unit from a 96 along with the blower, next would be to use a parallel flow universal condenser. The compressor will be a truck style r4 compressor which has the small diameter pulley for increased rpms at idle. Will be using a 96 reciever drier and orifice also. Hoses will be custom built. Ideas on problems welcomed. Im doing this to get 134 based parts in this vehicle for best performance possible. Thanks in advance Vic....

20mercury

My 2 cents;

1. 134 will work with your 12 designed components ok.

2. If you are going to do all of this work/money for a custom setup, I would just install Vintage Air. VA is kinda of pricey but sounds like you would spend some significant money going the custom route too.

bruiser

The R4 compressors are junk. Get a Sanden compressor.

Easy Mike

Take the car to any automotive AC shop. They can test your system and charge up the R12. They can also give you the skinny on conversion to R134. No sense throwing money after parts you may not need.

forvicjr

Mercury, yes 134 does ok in a r12 system but these cars are not known for the ac performance even when new. Vintage air dont offer a kit for my car only to 77. They will work but has to be modified.

Bruiser, Im aware of the r4 compressors but with my bracket setup on the bigblock and valvecover fitment issues im stuck with it. I have a sanden compressor on the shelf and looked at it. Its not worth all the changes that will have to be made.

Mike, Im an ASE auto tech, I will be doin all the work myself. No sarcasm just lettin you know my knowledge level. 80s chevy airconditioning sucks at best, even with r12. Ihave retrofitted many with dissatisfied results on performance of the conversion especially at idle speeds. Bein a tech also allows me to get the parts dirt cheap so thats non issue also. I just wanted to put this out there for u guys so maybe something I hadnt thought of could be brought to my attention. Thanks for the imput keep it comin.

forvicjr

And to add, only problem I have seen so far is that the reciever/drier plumbs directly to the evaporator and stock puts it in the fender well. The coolant recovery tank will have to be relocated to make room for it. The r4 compressor issue does annoy me but the sanden will have to be mounted higher to clear my valvecover and then hood clearance becomes a problem. The r4 is 1/4 from touching the hood now...

Street Rat

I bought a kit for my '81 from Classic Auto Air. It has the Sanden compressor. I also purchased a parallel flow condenser from them. I'm using a new factory evaporator core, adjustable orifice tube, and new accumulator. All with 134a. I have a black on black car with glass tops.
I live in Texas where the summers are at or about 95-100 degrees.
So far I am very happy with the setup. Heat Index today is 100-107.

mikem350

I cringe when I hear "take it to a shop and fill with R12" At $30-$50 a can, needing many cans, plus labor, oil, etc=$$$$$

That's even if a shop still carries R12

forvicjr

Yep, theres no way I could fit that compressor with the big block. Would be nice though.

68blvert

if compressor size fit-a-ment is a big issue look into using one from late model subaru impreza/ forester/ outback. about the size of an alternator.

rebel542

I converted my 79 to 134a with all stock parts, with the exception of a blue (Ford) orifice tube. Only other thing I did was a new dryer. 42* out of the center vents! Heat index today here in eastern NC? 110*!!! Not shabby.

forvicjr

I just did a conversion on an 85 silverado, got 41 on max. Im lookin to get into the 30's with my car. Outside temps was in the 90's and at got 41 at 800 rpm on the truck.

GUSTO14

Vic, I'm not sure where you're getting your information from, but I bought a new Corvette in 1977 and drove a number of new 1979's, 1980's, 1981's and 1982's. Every one of them would freeze you out of the car unless you adjusted the temp up. This was in the summer heat of Florida and other places in the deep South. The system was essentially the same system as in a full size Chevrolet, with just half the space to cool.

If the system is restored to like new, it is a very good system. I don't disagree with some of the changes you have suggested, but I do think changing the compressor (since you plan on making custom lines anyway) to a Sanden would be at the top of any list of changes I would consider.

Good luck and let us know how it works out... GUSTO

forvicjr

I really want the sanden compressor, it is just not goin to happen. I have to run tall valve covers and the r4 is the only thing thats goin to clear.

Street Rat

I guess I don't understand how the R4 can fit and the Sanden not fit. The Sanden is smaller in diameter. Is the Sanden compressor too long? I have tall valve covers on my small block. I had to cut an unused ear off to get the Sanden to clear. Just trying to help.

forvicjr

The r4 is the pancake shaped compreessor, im not running the a6 just to clarify. My compressor is situated in front of the valve cover. Nothing anylonger would fit without goin anothe route for brackets.

SciVette

Street Rat- Can you point me to the kit you purchased? As usual when you look for Corvette they stop at 1976... Thanks.

Street Rat

SciVette I sent you a PM.

Big2Bird

I am interested as well. Next time Sanden.

chrisviktorjakematt

I just did most of the same to my ac. I left the evaporator alone and replaced everything else for r134a. I got the biggest parallel flow condenser I could and it is quite cold. the only thing I have been told will increase cooling at idle is to put an electric fan on the condenser. Also clean all the contacts for your fan while everything is out of the way and you may notice a significant increase in airflow in the cabin.