'74 Scamp with the older heavy weight R12 system. I'm doing a complete engine and tranny overhaul and would like to get AC in it at the same time. Are we talking R34 and junk yard parts or what?

Thanks

If you live in the US, there's no reason why you can't continue to use R12. It works better (cools better) than R134a in an unmodified R12 system, and is compatible with all the materials and oils in your current system. And don't knock that "heavyweight" system! It's one of the best compressors out there. Sure, it's heavy, but so are your front and rear 1974 "Ralph Nader" bumpers and side guard door beams, and I bet you're not taking those off.

You do have options; you can find a '78-'79 car with the Sanden (avoid the Chrysler-Nippondenso C171) round aluminum compressor and have new hoses made and install a parallel-flow condenser and completely flush the system and then put in R134a. Or you can do any of several half-baked R134a "conversions" with those instant-compressor-death "R134a retrofit" kits from the parts store.

Either leave it alone or be prepared to do an extensive and expensive major rework of the system. Halfway measures will not make you happy (at least not for long).

I took my system out, I just thought the cost and benefit/benefit wasn't good for it. You do have hotter weather though, I only have to worry about 100 degree weather for half the year, the other half I got to worry about 0 degree weather . If I really wanted AC I'd probably try something lighter, then again I'm also the type that eventually plans to get fiber glass bumpers when I can afford it . In all actualality as slantsixdan said it would probably be a pain to change to a smaller compressor and I don't actually know of any AC made for mileage . In my opinion if you want to make the system lighter get ride of it and use windows or else take the easier route and keep it in(and those summer days will feel a lot better).

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My car may be slow to sixty, but at least it's been reliably slow to sixty for more than thirty years.

Dan, I sorta agree with you. If you can stay with r-12 you should. However, R12 is getting hard to find, at least in my area, and it is quite expensive. There are some vehicles that do not retofit well (a lot of Ford products). But other vehicles do take well to a retrofit. If your going to use the Sanden compressor, and a new style parrallel flow condenser, anyway, a retrofit to 134a should work fine. Actually most older cars will retrofit better then the newer cars, because they have so much extra BTU capacity, over what is required. My 1969 Polara, with the RV-2 compressor and totally stock condensor and fan, has a discharge temp of 38 degrees, running on 134a. What hurts cooling on a lot of retrofits is excess oil in the system, and/or not enough condenser capacity (no fan shroud, too small fan, or cond itself). You are totally correct about doing it right. Don't do a half baked job.
PS: I am a professional A/C tech, 40 yrs experiance.

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Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225

FRIGC FRIGC

Check this stuff out, do a google search.

R-12 Compatible, more efficient then R134A, and EPA Approved!

So you can upgrade to a more efficient sanden compressor, not have to retrofit car and get better cooling and not pay R-12 costs!

My frined with a 1966 Mustang Just used it.

Tim

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My Swinger gets the Highlight Valet Parking spot over the German sports cars on the Sunset Strip. I love my Mopar.

Whoah, bigtime NO!

FRIGC is nothing more than R134a with a small amount of R600 added to try to shore-up R134a's poor oil return characteristics. Performance and materials-compatibility are poor. FRIGC is legal, but remember there is *no such thing* as a "drop in" for R12, legally speaking. EACH AND EVERY different refrigerant is legally required to use its own unique service fittings and a fully compliant retrofit is required, including approved labelling. Just dropping "Gunk-12" or "Freeze-a-lot" or any other non-R12 substance into an R12 system is a poor idea for a whole bunch of reasons. When your system breaks (and with most of these substitutes, it *will* break sooner than later), it's hard as heck to find a service shop local to wherever you happen to be that'll work on it. Virtually every reputable shop has a refrigerant identifier. If they sniff your system with the ID box and it says anything other than R12 or R134a, most shops will say "Sorry, shop elsewhere". Because all refrigerants are required to be recycled (not just vented to the atmosphere as in the old days), a separate recycling jug/system is required for each refrigerant. Most shops have two and only two: R12 and R134a.

What's more, while FRIGC isn't on this next list, a lot of these "replacement" refrigerants are explosively flammable. (OZ12, HC12a, etc.). They work great, and they're cheap, and their proponents argue there's no safety issue "since you already carry around a bunch of gasoline and you don't worry about it", but the important thing to remember is that your A/C system was never designed to contain a flammable refrigerant, while your fuel system was specifically designed to carry gasoline safely.

I've tried the replacements. The one I had the most success with was Autofrost (R406a). It's nonflammable, legal, physically compatible with R12 systems and slightly more efficient than R12. But, it still has the unique-fittings/no-local-service problems.

Use R12 or use R134a. There is NO good reason to use anything else.

Take a look at these test results for a bunch of different refrigerants in terms of cooling power:

http://www.ackits.com/forum/messageview ... eadid=9171


-DS (PS, "EnviroSafe" is another flammable illegal refrigerant)

I totally agree with Dan on this. Use r-12 or r-134a only. Main reason, if you replace any A/C components, you will void the warrantee, if anything other then R-12 or R 134a is used. Myself, I have 3 refrigent recovery/recycle machines. One for R-12, one for R 134a, and one for contaminated systems (anything other then 12 or 134a) If my identifier detects a contaminated system, $50 is added to the service charge, to cover the cost of the machine and disposal for the "junk".

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Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225

Only $50 extra? Wow, you let 'em off for cheap...

I have the stock, under dash unit from an AC '69 Dart which I will sell cheap if you want. It will fit most A body cars from 67 to 72, and will mate with a later model Sanden compressor, and updated dondensor. You would still need to get alot of small bits and pieces to complete the system. I would recommend sending it to Classic Air in Florida, where they will rebuild the unit with new vacuum pots, and complete it for you with modern condensor and compressor.

I have heard the Sanden requires very little power. We have a local company here called Vintage Air that has equipment for the newer style style A/C. I have heard good things about them. I have a Sanden 508 in my '64 Valiant. The brackets came from a late model slant six car. It fits great.

The notion that the Sanden compressor "takes very little power" is a persistent myth, but a myth nonetheless. The Sanden is an excellent compressor, to be sure, but it is not magically efficient. The Chrysler V2 "paintshaker", while relatively heavy, is extremely efficient. It also lends itself very well to R134a retrofits because of its internal oil pump.

I was just reading about this same topic over on Moparts.com. Somebody was talking about "freeze 12" being compatiable with the old r12 stuff. You don't need to do all the conversion stuff to your system as if you do the complete conversion to r 134.
I know squat about a/c systems except that you turn them on they should work. I don't want to take my system apart, change oil and all just to convert to r134 and from tthe stories Ive heard about 134 is that the system with never blow as cold as the old r12.
I need more intell!

That is NOT correct. Freeze-12 is also just R134a with a little R600 added. And while it is a legal refrigerant, it requires ALL of the conversion procedures mentioned in my previous post for a legal and long-lasting retrofit, and it is subject to the same "can't find a shop that'll work on the system once it's filled with this crap" problem.

Use R12. Or use R134a.


***ONLY!***

There are many EPA approved "legal" refrigerants. Every one requires unique fittings, and labeling of the system. Some also require other procedures, such as high pressure compressor cutout switch, barrier hose, etc. There is NO, repeat, NO legal drop in replacement refrigerant for R-12. Also the EPA approval is just for environment concerns. The EPA has not tested any refrigerant for cooling effectiveness or, effect on the durability of the A/C system.

_________________
Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225