Considering what AC compressor to go with when I revamp my AC system. More than likely doing 134, if you had to pick between the ProTen A6 and Sanden 508 compressors, which one and why? Looking for best performance, not necessarily looking for originality. Any info would be appreciated.

 

The Pro6TEN is just Sanden compressor guts in a body that is roughly the same size as the original A6. While more expensive, the Pro6TEN will bolt to your existing brackets. The Sanden will require custom brackets and hoses. I used the Old Air Products kit to mount the Sanden on my 67 Delta. Their bracket is very well designed.

 

I used the Pro6TEN, so I could keep my OEM brackets and hoses. And I liked the way it looked vaguely like an A6. It fit perfectly.

From Joe's and my experience, either compressor type will work well.

Converting to 134A will require that you change the POA valve and condenser if you want the same cooling power that the factory R12 system provided.

You may know about this already, but reply if you need more information.

 

Nice clean engine compartment. Holy Smokes there is lots of RED..

 

Hi Gary. Im having issues with my compressor and after looking at the Pro6ten compressors as a replacement I see they have two different ones for my vehicle (1971 442) they sell a High Heat Style and a High Pressure Style, do you know the difference between the two? My vehicle already has the Olds Air POA 134A kit if that makes a difference. also what would be recommended changing since im going to open the system, expansion valve, and dryer? Thanks

 

I run the Pro Ten 6, purchased from Old Air, along with their drier, the expansion valve (Ac Delco) is available on Amz.

 

When opening the system, you should install a new dryer. Also the refrigerant oil is different between R12 and 134. Make sure you get it out of the evaporator. You could remove, drain, rinse using 134 oil, and replace. Or you could also [carefully] use compressed air to blow 134 oil through the evaporator to rinse it.

The reputation for poor cooling on 134 comes from the fact that it requires a more capable condenser than R12 does. Now would be the time to replace the condenser with a higher-capacity, cross-flow unit custom fit for Cutlass made by Vintage Air--p.n. 021172--it comes with a new dryer. Call them (800.862.6658) to discuss to be sure you get everything you need for the replacement.

Call Old Air Products (817.531.2665) and discuss three things:
1) Conventional wisdom says to replace your hoses because they do not have an adequate barrier for 134. I have read that, with age, our old OEM hoses have developed some kind of varnish internally that makes them OK. Get their take. I had them make new hoses for me but they used sub-standard insulating sleeves that deteriorated, cracked, and became even uglier within 2 years. If I had to do over, I'd use my old hoses.
2) Explain you want to use a Pro6TEN with a POA valve and get their take on the advantages/disadvantages. I replaced my POA.
3) High Heat vs High Pressure compressors. That wasn't an option when I did my AC system. But as I understand it, use High Heat if you live where it is 100°+ regularly, otherwise use the High Pressure.

Good luck!

 

Right on! Thanks for the help. Ill make some calls and see what im gonna go with. I think at this point I will just revamp the system and hopefully wont have any issues for a while. Ill post an update once i get everything installed.

 

I'm *assuming* the superheat variant has a superheat switch in the back that's exposed to the suction side. This goes inline with the clutch wire and opens (disengages) if the low side gets below a certain level - e.g. there's no refrigerant in the system. Several OE systems used a superheat switch in the back of the A6, including my '72 Supreme. This switch will protect the system if there's a leak.

The high pressure variant probably has a pressure switch exposed to the discharge side. It also goes inline with the clutch and opens (disengages) if the high side goes to high - usually over 350psi. This protects the system if it's overcharged, which isn't a concern on an OE-built (and maintained by OE dealers) system.

Aftermarket setups tend to use a trinary switch which goes in the high side somewhere and disengages the clutch if the pressure is too high or too low.

 

Okay so I finally got the new Pro6ten compressor, I ordered the high pressure version not the high heat. A few questions about how the POA wiring works as someone else spiced it in, along with some pictures of my old compressor making sure its not a high heat version.

Curious if this is wired correctly one wire goes from the POA to the evaporator box and one to the clutch on the compressor.

Is this a factory plug? It was hidden/tucked away by the evaporator box. Is that a jumper?

I bought a new expansion valve. Not sure how to replace the (probe?) that goes in between the material wrapped around the hard line.

Also is this a high heat version of the A6? I was able to get a charge on it and cool air but it was making crazy noise from either the clutch or compressor itself so I decided to upgrade.

Thanks for any help just making sure I'm getting this right the first time around.

 

The Olds A6's of this generation were super heat. It's not critical which type you get - they're both safety interrupt switches that prevent the clutch from engaging when things are problematic. You don't have to include them in the circuit.
The material on the evap tube is called "cork tape". It's a long strip of cork, 2" wide, soaked with tar. Autozone usually has one dusty box on their shelves. Good insulator and easy to wrap and mold. You can just cut through it, pull it off, then wrap it back around. Super sticky stuff. There are different shapes and sizes of expansion valve probes so it might take a moment to figure out how to get it secured in the little brackets.

You don't have a POA any longer. That's now a cycling switch. It's advertised as an "upgrade" but it's not - it's just a different way of controlling the refrigerant flow. It's simpler and cheaper which is why most manufacturers started using that style in the 90s.

Looks like you should pull apart the wiring to see what's going on and make some fixes. Someone got pretty creative! The brown wire from the evap box is bringing power to the clutch. The two pin connector on the evap is a freeze switch - it interrupts the circuit if the box gets below freezing. From there you go into one side of the switch hanging off the side of the ""POA"" tube, the other side of that switch goes straight to the clutch. The clutch may have one or two wires. If it has one wire then the other is already grounded to the compressor body. If it has two wires, then one wire just goes to ground.

If the compressor was real noisy them it might have been spreading trash in the system. Try to flush everything as much as you can. Flushing the evap is a real mess and difficult to get everything out of it.

 

This is the evaporator pipe with the XTV probe clamped on. The copper leads need a bit of manipulation to position, the oil line takes a 7/16” open end, and 2 open end wrenches to install the XTV. All the o rings need a generous coating of pag oil, and carefully tighten the nuts, don’t over tighten.

 

Insulation installed. I bought the Delco stuff at P&R in Richardson Tx many years ago)

 

Right on thank you for the info! I had to order the cork tape off amazon no parts stores in my area had any and most didn't know what I was talking about. dc2x4drvr is that a Pro6ten compressor and Did you paint it black? I thought about doing that to mine to keep the more original look.

 

Yes, Pro 6 Ten, painted.

 

So not sure if I ordered the right dryer. The current dryer in the car is installed on the line between the condenser and expansion valve with I'm assuming like barbed ends and hose clamps. I for the life of me cant get the dryer off the hose with out probably having to cut the line. also the new dryer I got has threaded ports which wont work with the way my current dryer is connected. Is the dryer supposed to be connected like that or do i need a different line (what do they call that line?)Thanks Pics below

 

The line to the drier normally has an 90* pipe ending in a threaded male fitting to the condenser . Your line has been hacked a little. One of the guys here probably has the correct line.

 

Is the dryer supposed to be connected to the line that goes from condenser to expansion valve? Or is the correct dryer threaded and goes somewhere else?

 

After looking at the CSM it looks like somebody changed the set up quite a bit. Looks like they might of changed the condenser with one that's not original and put the dryer in the engine bay. There is no dryer in front like it shows in the manual or a place for one to live. I might have to order a new condenser, dryer, and line that goes to the expansion valve. I was trying to save money without buying a new condenser but now I guess I have to LOL.

 

Its an opportunity to get a parallel flow condenser for better cooling, especially if you are going to 134.
e.g. :

68 69 70 71 72 Olds CUTLASS 442 Condenser 3014915 AC1760PF EV6177 Drier bkts Kit | Cooler Classics

 

This is the direction you should be going to get the cooling you expect. See post 7, paragraph 2.

 

Okay so I went with the Vintage Air. SKU 021172 its advertised as a parallel flow condenser. I plan to install it tonight but was wondering about how much 134 and PAG oil to add. The new compressor came with 220cc of PAG 46 oil, since I'm replacing the condenser assuming the old one would hold some oil and the rest of the system would have residual oil, how do I know how much to add? Also for the refrigerant the manual says to add 4lbs of R12 so do I add 80% of that of 134? (64oz X .8 = 51.2oz) Just trying not to burn up a new compressor if i can help it thanks!

 

Do your installation this weekend (the time consuming part) and ask Vintage Air on Monday about the finishing details.

They will have good advice about oil and refrigerant charge.

 

Interesting, which ac compressor are you going to use?

 

Yes that (below image) is a factory plug. Likely someone removed the DVCS (Distributor Vacuum Control Switch) from your intake manifold - many owners remove the DVCS. The x2 green wires & the attendant plug/connector (in your hand) connect(ed) to the solenoid located on top of the DVCS. The other end of those x2 green wires connect(ed) to the transmission. If someone removed the DVCS, & its accompanying top-mounted solenoid, the plug and the x2 green wires are no longer required/needed. You can leave them connected to the transmission w/ no issue. You can hide the x2 green wires and solenoid (resistor) plug wherever is your liking. Page 6K-12 (Engine Cooling) Fig 6K-19 of the 1971 CSM or whichever Fig. is appropriate for your engine & equipment.


1971 DVCS

 

Location of DVCS 1971 intake manifold.

 

Thanks for the info Vintage Chief. So I installed the Olds Air compressor and when setting up the brackets and dryer on the new Vintage Air condenser I realized an issue with the hose routing. The Vintage Air condenser is supposed to be a factory fit for a 71 442 with or without air. If you read my previous post someone installed a non factory condenser and the dryer was spliced in, in the engine bay. So I ordered a new line that goes from the dryer that is supposed to be mounted in front of the condenser to the expansion valve along with the Vintage Air condenser dryer combo SKU 021172. Some pictures below

So I ordered the new line that goes from dryer to expansion valve which looks just the one from the CSM


Here is the new hose. Dryer to expansion valve.


Here is the line that came with the kit that goes from dryer (out) to expansion valve.

This is the hard line that goes from the condenser to the compressor with the muffler.




Is the dryer hardline in this kit wrong? The CSM looks like the line (out) to the expansion valve is coming off of the driver side of the dryer and the kit i have has that crazy long hardline coming off the passenger side of the dryer. Sorry for all the pictures this is confusing me. I feel like this direct replacement kit isn't so direct.

 

The condensor is designed to work with their entire kit, which uses a very different hose routing that runs through the blower fan hole in the cowl. By "factory fit" they mean it mounts in place and they are really talking about the entire kit since the interior box uses the OE vents and OE-ish control unit. The standard aftermarket condensors are very different than the OE so mounting takes a little bit of creativity to get them mounted.
The connections on that one are in a slightly different location but you could get stock tubing and hoses to work with some effort.
Don't use their condensor-to-dryer tube. Get an OE tube. You can bend A/C tube with a tubing bender.

There was one company that made a true OE-fit parallel flow condensor but I'm not quickly finding it. Maybe the OPG unit?

 

You sir are correct. My fault for assuming factory fit was going to be and OE replacement. I spoke with them this morning found out its part of their kit not a stand alone replacement condenser. Now I get to pay return shipping and a restocking fee. However I did find from a company called Cooler Classics, they have a parallel flow condenser with drier on Ebay advertised as direct replacement about $400 with shipping. Should I post updates to this thread when the new parts come in, not sure if it would help anyone else out down the road I'm still new to forums and how they work.

 

Definitely! Please post an update so others can know how that unit works.

 

THAT IS NOT A DVCS PLUG! That is the factory compressor plug that is in extremely good condition. Since your system has been heavily modified, it may be redundant. That plug should have a ground ring on one lead, and the other supplies the 12 volt positve to turn the compressor on. You have aftermarket safety switches/sensors on your A/C sustem so you will need to find out if that plug still functions, or if an aftermarket lead now controls the compressor.

 

Hmmmm....I thought factory compressor plug wires were purple or blue & black? Don't have the CSM in front of me at the moment. I know my DVCS plug was green/green.

 

Take another look at the pictures you posted. GM never made a jumper that would reach from the evap box all the way to the front of the intake manifold, and the DVCS plug never had a resistor on it.

 

Sorry for the late update, got super busy with work and family stuff. The parallel cross flow condenser from Cooler Classics was a direct fit and lined up with all the factory hoses. After getting everything installed I pulled vacuum for 1.5 hours and the held the vacuum for 2 hours to make sure the system was tight, however I did have an issue trying to charge the system through the manifold set. I realized the brass piece that "punctures" the can and allows the refrigerant through the yellow hose wasn't working unless it was in a certain spot. Normally you would screw it all the way down to poke a hole in the can and then back it all the way off to allow the refrigerant to flow out but I think the cans I have are self sealing so it wasn't allowing anything to come out, not sure if anyone else has had this problem. I decided to take it to my buddy's shop and use his machine and added 3.2 pounds of 134. It took the first 1.6 pounds quickly and the rest went in super slow, almost an hour to get the rest in not sure why. So far its good, blowing around 48 degree air on a 98 degree day. The only issue I have is my idle is set around 7-800 RPM, when I put it in gear my RPM drops to around 6-500 RPM, and when I turn the AC on, on top of that it drops to around 400 and runs like it wants to die out. Is that normal to drop that much in gear and with the AC on? If I turn my idle up to compensate for that I feel like it will have to be around 1000 RPM at idle.

 

Engines with higher-performance cams drop like that when any extra load comes on at idle. I had the same problem. I retrofitted an electric idle-stop from an earlier Cutlass. It pops out when the AC clutch comes on and I adjusted it to maintain the same idle speed through that transition.

 

I had a similar idle drop issue many years ago. I had set up the distributor with an advance curve kit using the weakest springs. I discovered those springs were allowing a bit of advance at idle speeds, so when the AC turned on, the idle dropped, which made the advance decrease, which made the idle drop even more - essentially a death spiral. Installing the medium springs and resetting the initial advance made it much better. I then reconfigured the mechanical advance to give 16 degrees (factory was 24) and was able to set the initial to 18 (factory was 10) and the idle speed doesn’t drop when going into gear or when turning the AC on. It also increased the idle vacuum from a bouncy 15 to a steady 17, which made the brakes work better.

 

I'm shocked it keeps running at 400 rpm!
Yeah, you need to either add an A/C kick-up solenoid or wind up the idle for the summer.

 

Thanks for the info! The cars new to me and I'm looking into upgrading the points distributor to a HEI Pertronix Ignitor II. Could this possibly solve the issue it looks like that distributor comes with different advance springs. Also what causes the issue of the idle drop? Is it the vacuum load on the distributor? Does it make a difference if you use manifold vs ported vacuum for the distributor? Just trying learn how it all works and if I could avoid adding solenoid. Thanks

 

I can't say anything about the Pertronix Ignitor II. It may be OK, or it may be a pile of junk. I have on experience with them as I have always used factory GM distributors (points and HEI).

I would suggest not changing the distributor just yet. you can get an advance spring assortment for your points distributor and play with that first to see if you can make a significant difference.

 

If the problem is in the distributor, it would be caused by lower timing when the AC turns on.

• Fun71 is explaining that light advance springs may cause the timing to drop when the engine rpm drops. You would try stronger advance springs to see if that helps maintain idle speed.
• As you intimate, it could also be caused by the vacuum advance being connected to manifold vacuum. In that case, the timing will drop when the manifold vacuum drops with lower rpm. If you are connected to ported vacuum, the vacuum advance will not react to manifold vacuum change at idle.

I had pointed out another possibility--a performance cam. In that case, the reserve engine torque at idle is low. And the additional mechanical load (AC compressor) reduces the rpm.

Because the AC load decreases with rpm, the idle speed continues to drop until there is a balance of available torque and AC load.