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Replacement Compressor For A6

69Sixpackbee on Wed December 19, 2007 11:55 PM User is offline

Year: 1972
Make: Chevrolet
Model: C-20 Pickup
Engine Size: 402
Refrigerant Type: 134A
Country of Origin: United States

I have decided that after several years of farting around with sub-standard aftermarket systems I have decided to install the factory 4 Seasons back into my Chevy pickup. The only thing that I am not going to put in is the original A6. I am going to stick with the POA setup (adjusted to operate on 134A or maybe sticking with R12...dunno yet) and all of the factory stuff. It is a non-A/C cab now but a little sheet metal work on the firewall and I can adapt the original setup no prob. Suffice it to say I am tired of a total recirc setup when trying to use the heater. Fogged up windows constantly is a PITA! Yea, I can keep running the compressor to dehumidify but why when I can go back to the factory setup that has the fresh air in like all systems have.

Anyway, enough digression. My original topic is what compressor can I use in place of the A6? I currently am running a Sanden SD5. Is this stout enough to run at continuous duty? Is the 5-cylinder sufficient enough to keep the evaporator satisfied with the larger factory evap?
Can I retain the oil line from the evap to the POA with a Different compressor?

I had a complete set of big block compressor bracketry but I made a good deal of $$ selling these rare pieces so I am relegated to keeping the Sanden (or one similar) in place.

The current system is an R134A setup with the correctly sized components and works very well but I might entertain going R12 (I have 60+ lbs lying around and might use instead of hoard! Otherwise I will settle for 134A with the proper adjustment of the POA.
I have seen where lots of folks opt for the POA eliminator but I like a non-cycling setup myself.
Anyway, your thoughts are greatly appreciated!

Thanx and Happy Holidays!!

Bud Weaver



Edited: Wed December 19, 2007 at 11:59 PM by 69Sixpackbee

69Sixpackbee on Thu December 20, 2007 12:27 PM User is offline

Found this:
http://www.autoacforum.com/messageview.cfm?catid=2&threadid=15398&FTVAR_MSGDBTABLE=

Looks like an answer to my question. Now I spec'd out the A6 and the Sanden I have now. The A6 has 12.6 cu/in. capacity and the SD5H14 like I have is 8.4.

Is this difference much to be concerned with?

At least I have a small cabin to cool.

Thanx,
Bud

Edited: Thu December 20, 2007 at 12:38 PM by 69Sixpackbee

bohica2xo on Thu December 20, 2007 1:10 PM User is offline

12.6 cid vs 8.4 cid....

Well you could just destroke that 402 down to a 268 cubic inch V8 - you would have the same thing. Sure you could get the same performance from a 268, but not in the same rpm range - you would have to spin the 268 to 15,000 rpm...


If you want to do a custom install I would seriously consider using a V7 (or even a V5) GM compressor with your OEM HVAC assembly. You will still have evaporator pressure control, but it will be built into the compressor instead of the POA valve you have right now. The V5 / V7 is good for continous run applications like the A6 was, but is smaller & lighter. A "V" belt drive can be had on either compressor, as well as the standard serpentine drive.

POA valves are a limited resource, and are expensive. Moving ahead 20 years to a V5 / V7 type compressor makes sense for a hot rod, where you are not looking for 100 point status.


B.

-------------------------
"Among the many misdeeds of the British rule in India, history will look upon the act of depriving a whole nation of arms, as the blackest."
~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446.

69Sixpackbee on Thu December 20, 2007 1:34 PM User is offline

Great info!

How would I plumb up the V7 into the orig. POA/TXV setup? What about the oil line of the existing evaporator?
I read your write-up on the RCV eplacement BTW. Informative!

Thanx,
Bud

Edited: Thu December 20, 2007 at 1:38 PM by 69Sixpackbee

bohica2xo on Thu December 20, 2007 1:52 PM User is offline

Bud:

You would keep the OEM TXV, it is right for the original evaporator. The POA valve becomes another part you can sell for big bucks. In it's place you just plumb the evaporator discharge to the V7 suction port. Cap the oil bleed line, and you are done. You will need a service port someplace in the low side, so plan on that when you select fittings.

The V7 was used in things like 4 cylinder S-10's... and Corvettes. It will take very high rpm's and has a lot of capacity. I can e-mail you the OEM spec sheet if you like.

This is a wild guess at this point (no time to research it for ya right now), but I bet there are some brackets out there for the V5 / V7 to fit a big block. If not, then perhaps you can modify the OEM smallblock brackets.


B.

-------------------------
"Among the many misdeeds of the British rule in India, history will look upon the act of depriving a whole nation of arms, as the blackest."
~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446.

69Sixpackbee on Thu December 20, 2007 2:04 PM User is offline

super!!

Any info you can send my way is greatly appreciated!
You know, I never even considered a variable displacement compressor. It might well fit with just a little modification to the existing Sanden brackets. Hoses are a piece of cake . I have a local shop who makes them up for me so I can have him weld in the service ports.
Thanx again for the advice!!

Merry Christmas and happy New Year!

Bud

69Sixpackbee on Thu December 20, 2007 2:27 PM User is offline

Thanx again..

Edited: Thu December 20, 2007 at 4:42 PM by 69Sixpackbee

ice-n-tropics on Thu January 03, 2008 12:16 PM User is offline

Bud,
If you want to keep your present compressor mounting bracket and a fixed displacement compressor you can replace the 5 cylinder with a drop in AC KITS SD7H15 Sanden. This ups the displacement from 138 cc to 154.9 cc for additional capacity. That's still less than the 212 cc A-6. Using the large OEM HVAC unit, you can't hang venison inside without the A-6.
I modified my 74 Silverado OEM airflow to provide 100% recirculation in the max cooling mode. Wasteful sucker drew in about 30 to 35% fresh hot/humid air otherwise. GM said it was for heavy smokers.
Cordially,
Old IV guy

-------------------------
Isentropic Efficiency=Ratio of Theoretical Compression Energy/Actual Energy.
AMAZON.com: How To Air Condition Your Hot Rod

tony1963 on Thu January 03, 2008 6:42 PM User is offline

I wouldn't replace an A6 with anything else.

-------------------------
Grove Automotive Group, Inc.

An Alabama Corporation

69Sixpackbee on Thu January 03, 2008 6:47 PM User is offline

Quote
Originally posted by: tony1963
I wouldn't replace an A6 with anything else.
True but acquiring the brackets alone are more $$-wise than the compressor alone therefore making it cost prohibitive and besides, I like the mounting position of my current setup. Have you ever tried to do routine service, i.e, valve adjustment, plug R&R, etc. with that big log hanging off the side of the engine?



Edited: Thu January 03, 2008 at 6:47 PM by 69Sixpackbee

tony1963 on Thu January 03, 2008 7:28 PM User is offline

The brackets are the same pickup to vehicle on certain model years. There are companies out there that make brackets that are OEM replicas.

-------------------------
Grove Automotive Group, Inc.

An Alabama Corporation

69Sixpackbee on Thu January 03, 2008 8:11 PM User is offline

True, but I like the size and the mounting location of my current setup. Noone will argue against the validity of the A6 compressor. It was GM's staple compressor from Silverado's to Seville's...one size fits all. Easier to stock and cheaper to produce when you can supply fitment across the board. Conversly, a 1972 Chevy pickup with a much smaller cabin than an Eldorado can be sufficiently cooled with a smaller compressor, don't you think? I have completely insulated the interior from the floor to the headliner and even the insides of the doors. I use Dynamat-type of asphalt sheeting sound deadener as well the reflective encapsulated bubble wrap. I even put a layer of thin fiberblass insulation topped with the same reflective insulation on the entire surfaces of the evaporator housing.

That is just the tip of the mods I did to keep the cabin cooler. Tinted windows also have helped. My last system (underdash) kept the cabin extremely cool. I was getting vent tems consistantly in the mid to upper 30's on the hottest of days. Traveling accross the deserts into Texas is necessary. No cooling woes. I just have decided that I wnt the versitility of the factory Four Season system primarily for the heating aspect and well as blendible temperstures. All parts are up to snuff and the outside air plenum flapper seals perfectly.

I will start off with my current compressor. If it is "not up to par" I will venture into the V5/V7 realm and lastly I will consider the A6 back into the engine bay....lastly. I like wrenching without major obstructions.

tony1963 on Thu January 03, 2008 9:02 PM User is offline

I would suspect that the time and engery expended for the retrofit would be far in excess of all of the time expended during routine service due to the unit being in your way.

However, there is a feeling of accomplishment when you are able to engineer your own success. Best wishes!

-------------------------
Grove Automotive Group, Inc.

An Alabama Corporation

69Sixpackbee on Fri January 04, 2008 1:17 AM User is offline

Quote
Originally posted by: tony1963
I would suspect that the time and engery expended for the retrofit would be far in excess of all of the time expended during routine service due to the unit being in your way.



However, there is a feeling of accomplishment when you are able to engineer your own success. Best wishes!

...plus, I am just a cheap so-and-so :0
Thanx for the kind words and knowledgeable advice..from ALL!

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