Time to put the A/C back on my 70 GS

Discussion in 'The Big Chill' started by LARRY70GS, Jul 18, 2017.

  1. buick64203

    buick64203 Just plum crazy Staff Member

    R134 will never cool as well as R12. You'll get snowballs out of an R12 system. If you go with 134, you'll definitely need an electric fan.
  2. guyver002

    guyver002 Well-Known Member

    I am looking to get the A/C in my Buick working in the future as well and have definitely been reading this thread! I wanted to add one of my particular problems to the list of obstacles one may have to overcome because it may help another.

    A previous owner seems to have attempted to use 134a in the system and one of the metal lines going the condenser appears to have busted because epoxy is is wrapped around a spot on the line. I wonder what other damage could have been done to the system if the 134a was run improperly.
    Also I have R12 I can put back into the system when it is ready but that is yet another dilemma I noticed and that is the R12 fitting for the gauges have been replaced with the 134a type. Where can I find the correct R12 fittings I see no place to buy them.
  3. elagache

    elagache Platinum Level Contributor

    Dear snucks, Larry, and V-8 Buick cool-cats,

    Unfortunately you are overlooking the key advantage of these newer systems - efficiency. They simply aren't anything close to the load of A/C systems of the day. With a big-block engine, there is simply nothing to notice when the A/C is going.

    My car has laptop adjustable EFI and it turned out that the rpm adjustment for the A/C could be easily lowered. It is now I believe only 50 additional rpm.

    Cheers, Edouard
  4. musclecarz

    musclecarz Well-Known Member

    I restore factory ac and heater parts. I restored 87GM_70GS ac unit and heater box. Here is a link to my FB page with the pics. https://www.facebook.com/factoryautoair/posts/620198981501878
    If you want to keep the factory ac and run r12 then no upgrading is necessary. Just need to check/repair/replace whats needed. If wanting to go with 134a then the poa valve should be recalibrated and a parallel flow condenser should be installed. The issue that no one makes a bolt in PF condenser for 68-72 Skyark. Classic auto air makes them for the other 68-72 a-bodies but not Buick. There isn't a more efficient evaporator. The factory style evap works fine but you would want to flush and pressure check to make sure it doesn't leak. The steel is A6 is robust but it tends to leak from the shaft seal. Even more with 134a. You could get a double lip shaft seal to help remedy this. The Sanden is a tried and true compressor as evident by use by the OEMs and by all aftermarket companies. Lighter and less hp draw but it just looks out of place if factory appearance is important to you. Plus there is the issues of it needing its own brackets and possible hose setup. The aluminum A6 replacement that's commonly referred to as the Pro6ten or S6 also lighter and uses less hp along with accepting the factory brackets and hoses. It can be painted black to help blend in better. Neither of these compressors have the oil slinging issues. If you use these compressors then you could use a cycling switch but a lot of guys don't care for that. And if anyone is interested in check it out here are a couple of videos I have on an ac unit that I restored.
    chiefsb30 likes this.
  5. snucks

    snucks Well-Known Member

    Here in California r-134a is artificially pricey due to requiring a 10.00 core charge for each can purchased. Between this and the fact that an r-134a hardware set up would require a lot more money in parts it was pretty easy decision for me. I no longer make very much money so every decision is viewed through a cost:benefit ratio.

    If you really wanted to go full on performance look into replacing the insulation under the carpet and the door and glass seals along with tinting the windows as the original tint may have lost some of its UV protection over the years. A new windshield with a fancy super light tint would go a loong way in dropping temps.

    fwiw: back on the the 7th it was 111* here and my brother commented that my ac was colder than his modern Land Rover

    so to summarize

    assuming a person still has all stock components that are functioning normally (like me)

    1. 2nd cheapest option
    2. works very well with temps ranging 31-50ish*
    3. r-12 can be had between $20 and $30 a can (need 4-5 cans)
    4. requires no hardware mods
    5. robs most power

    Stock using snucks brand alternative refridgerants:
    1. cheapest option
    2. works very well with temps ranging 31-50ish*
    3. duster cans are $3 a piece (need 2-3) envirosafe $6 a can (need just one)
    4. requires no hardware mods
    5. 'maybe' robs a tiny bit less power due to slightly lower high side pressures

    stock with r-134a conversion:
    1. a bit more expensive because it requires extra parts like either an extra electric cooling fan (as little as 30 bucks) or a parallel flow condenser (around $200)
    2. requires adjusting the POA valve
    3. works ok but not as well as r-12
    4. r-134 is easily obtained if anything goes wrong and is cheap in most free states.
    5. still robs more power
    6. looks close to stock if condenser option is used but not stock if electric fan was installed.

    Complete Pro6ten conversion using r-134a:
    1. over 1k in parts costs
    2. performance around but probably a bit better than a good r-134a conversion
    3. substantially lighter and requires around half the hp to run as stock
    4. doesn't remotely look stock (if that's your thing) even more so if using a regular Sanden compressor

    I use a single can of envirosafe because the propane helps with carrying the oil through the system and it also happens to have some dye in it and a pine scent which makes finding leaks a ton easier
    Last edited: Jul 25, 2017
    Harlockssx likes this.
  6. elagache

    elagache Platinum Level Contributor

    Dear musclecarz, snucks, and V-8 Buick cool-cats,

    Okay, point well taken. My wagon didn't come with factory A/C so that really tipped the balance in my case towards aftermarket systems. Cost aside, there is a considerable effort involved in getting these generic components to fit. In Larry's case, he is probably better off to stick to stock components unless he wants the challenge (and bragging rights) of getting a more modern and efficient A/C.

    Another very good point that is repeated my most vendors. A station wagon can be great for lots of things, but that long metal roof is an extremely efficient solar thermal panel! I'm planning to insulate as soon as complete some electrical upgrades that need to go above the headliner.

    Okay, but if Larry is willing to spend the extra money, the Pro6Ten compressor seems to be a real improvement in efficiency. It seems like the path of least resistance if you want higher efficiency but won't want all the hassles of shoehorning an aftermarket evaporator unit behind the dash.

    I'm confused. Why doesn't it look at least approximately stock? I thought the Pro6Ten compressor had the same dimensions as the OEM compressor? So what looks so different from the Buick factory install?

    That might be due to the superior insulation in modern cars. Back in the 1960-70s the cars got hotter, so the A/C systems were larger to compensate. Perhaps that's another reason to modernize an existing Buick system than to go completely aftermarket.

    Cheers, Edouard
  7. snucks

    snucks Well-Known Member

    The sides and rear window are tinted on my car but the windshield is original and it lets a ton of heat in. WAY more heat than a modern vehicle does. Today on the way home from work it was 93* and I have to drive west directly in the setting sun to get home. Air coming out of the vents was in the mid to high 30s but there was a crap ton of heat radiating off of the dash. Its a fight the system can eventually win but is unnecessary. My windshield has millions of tiny specks all over it from years of use and I'm looking to replace it anyway so when that day comes I will definitely be getting some very light tint applied to it because soon after comes battleship gray paint and its black vinyl roof lol

    I get fixated on one thing for months at a time and for a little while it was automotive ac systems. I was so obsessed I was carrying around my ir temp gun and pocket thermometer taking readings and making note of ac settings on my friends and families vehicles. Lots of trial and error in getting it working just right.
    I literally have a 14" electric fan in my amazon cart as I type this because I'm curious to see if it can get idle temps down into the 30s when its 100*outside.....gah!

    The Pro6Ten compressor looks stock (when painted black) but the hardware and hoses outside of the evaporator do not.
  8. HotRodRivi

    HotRodRivi Tomahawks sighted overseas

    Larry , the absolute cheapest way with a little modification is to use dry ice ware the evaporator sits. Yeaahhhhhhhhhh maaannnn.
    Or dangle some dry ice in front of your vents.
    Also if you get this thing called the cool towel, wet it , ring it, place it around your neck, with air venting on it feels like an ice pack is around your neck. It looks the same as the absorber car drying towel.

    I have seen toyota ac compressors used in muscle car apps. They are aluminum.
  9. HotRodRivi

    HotRodRivi Tomahawks sighted overseas

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  10. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    It would be if I had insufficient funds.:D
  11. Mart

    Mart Gold level member

    I too am going to gather my original parts together to re-install the A/C, like some of you guys. Great options here, Think I'll just stay with the R12. It used to throw ice cubes out of the vents at you!:cool:

    Was out on Woodward last night. Lots of cars, would have been nice to be comfortable at slow speeds, and waiting for the lights.

    Vinyl seats kinda suck. :D
  12. buickbill

    buickbill Well-Known Member

    well its been a year ,how did things turn out larry ? ive got to figure out what to do with my a/c . have a new orig. compressor and drier . need both lines that attach to the comp.. tried before to do a 134 swap on a 70 riv.. never worked. what im reading here seems to say keep r12 . can I get r12 in ca. for 20 dollars a can . thought it was $100.oo ! so , ishould I start replacing whatever is bad and keep all stock system . and where is the best place to get replacement lines??
    Harlockssx likes this.
  13. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    I'm a big procrastinator. All I have done is buy a new evaporator and install it in the box. I just took my hood off today and will remove the right fender this week. It is unbearably hot and humid here so I will do a little everyday. After that, I will look at a new compressor (gonna go with a new Pro6ten ), a new condenser, dryer and POA. Think I am going with R12 as well. The lines are the last thing I will do. I'm going to have 2 simple lines made up. No way I am going with the bulky OEM lines with that stupid muffler.
    Dadrider likes this.
  14. buickbill

    buickbill Well-Known Member

    well plans have a way of changing. ive been going to install a oil pressure gauge , but put it off, and yesterday went for a drive. very hot here ,and smoke fills the air 24/7 .car ran so good I thought I would start on the a/c .today installed the gauge . air is the least of my problems . basicly no oil pressure , soooo
  15. gsla72

    gsla72 Well-Known Member

    Larry - Where are you sourcing your parts? I'd like to do a similar setup (factory air car but my compressor is bad) but with r134.
  16. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    The only thing I have bought is a parallel flow evaporator. I installed it in the box and and am installing the box into the car. Been working 2-3 hours a day as the heat and humidity really take a lot out of you. I bought the evaporator from Classic Auto Air.


    Gonna shop around and get the best price on the Pro6ten compressor. Not sure whether they make a parallel flow condenser for our Buicks, I know they do for the Chevelle, but theirs are different.

  17. cray1801

    cray1801 Too much is just right.

    Thanks for keeping us updated Larry. I'll be doing mine here in the next 6 months or so.
  18. Christopher Spouse Drew

    Christopher Spouse Drew Well-Known Member

    Forever who needs this information on prices of the cheapest but quality a/c parts. I will say utilize and wait for the ebay coupons. I went with upgraded stuff because I want a brand new working and efficient system. My setup is for 134a.
    Evaporator($229) with coupon, even cheaper-https://www.ebay.com/itm/1968-72-Cutlass-GTO-Skylark-Air-Conditioning-Evaporator-GM-3014086/272516199470?fits=Year%3A1971%7CModel%3ASkylark%7CMake%3ABuick&hash=item3f733b342e:g:3wUAAOSw9GhYdAAS:rk:2:pf:0
    Upgraded POA Valve($95) with coupon, even cleaper-https://www.ebay.com/itm/POA-Valve-...e=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649
    Parallel Flow Condenser($42) with coupon, even cheaper-https://www.ebay.com/itm/AC-Condens...h=item417df666d3:g:b1sAAOSweEFbBcR-:rk:2:pf:0
    Pro6ten Compressor($345) with coupon, even cheaper(I was lucky to buy a brand new Pro6ten for 270 on ebay)-https://www.ebay.com/itm/Pro6Ten-Compressor-Upgrade-SH-Aluminum-1-Groove-21-2201SH/202030974722?epid=1541399999&hash=item2f09fc0702:g:Ie4AAOxyyF5RJ8VT:rk:1:pf:0


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