Corvair Forum

My 64 Monza convt had a "Climatic Air" a/c system,# 56900 in it when I got the car last year. It is getting an upgrade with a new SD508H14 compressor. I am looking at new condensers and would like to buy one that has the filter/drier attached to clean up and simplify the plumbing.The condenser will be shrouded and mounted to the engine cover,and thus the drier would be horizontal with the "bonnet" closed. Historically the receiver is mounted vertically in the engine compartment of front engine vehicles and with a sight glass to see the "bubbles". I want to think that the long run of the new 3/8" copper tube for the high side to the front of the car, via the tunnel, will allow any bubbles to chill out .The new condensers(no sightglass) are very efficient, mach lighter than what was originally installed, and plentiful.
So any one have some insight, and or some experience with upgrading an old add on system?
Paul

Clark's Corvair Parts has a full line up of aftermarket A/C systems for Corvairs.

https://ssl.corvair.com/user-cgi/catalo ... w_page=317

https://ssl.corvair.com/user-cgi/catalo ... w_page=314

Thank you, I have bought parts from Clarks since 1978, and very happy to do so. I kind of brag about them with folk who think Corvairs would be hard to find new parts for, Thank you Clarks and all the other vendors, gurus and good guys who keep these cars rolling.
I will upgrade what I have,and would share the result with any one if there is interest.
here are a couple pics,

You might look at the EM factory A/C see attached.

I'm an NOT an A/C expert, but this is what I've learned over the years.
There a two basic systems:

One is a TXV expansion valve that regulates the amount of refrigerant into the "evaporator" to make sure all the refrigerant evaporates and uses a thermal switch cycle the compressor on/off to keep the evaporator from getting too cold.

The other has a by-pass valve that allows refrigerant to by-pass the evaporator if it gets too cold (this system is easier on the compressor as it keeps pressures in narrower range).

The Sanden SD5 has a reputation for "growling" as it ages, especially in the reverse rotation Corvair. Sanden used to state you could turn the compressor either way - THEY NO LONGER DO THAT!

Clark's went with the SD7H14 seven piston unit (fits same bracket, but pulley size is different), BUT Sanden does not approve it for reverse rotation, but a call to their tech department by a poster on a forum got the reply - "Yes you can run it reverse rotation, but it won' t last as long."

The CONDENSER - R134a has an issue GIVING UP HEAT so Clark's LM bulkhead condenser uses a combination serial/parallel tube design (first made by Rusty's Corvair A/C parts) to SLOOOW down the R-134 so it stays in the condenser longer to GIVE UP MORE HEAT. Electric cooling fans are HIGHLY recommended to keep coolant pressure from getting too high. R134a pressure per temperature increase is more agressive vs. the old R12. Clark's sells a EM lid condenser with a fan, I do not know if it is designed for R134a, CALL THEM. BTW the Clark's system uses modern "O" rings connectors. I used the Eaton E-Z clip system for hoses and connectors. I found them at the Hose Warehouse when I converted my 1966 factory system to R134a.

The DRIER - Most designs have to sit verticle to work properly. FORGET the bubble port used with R12 - it is meaningless for R134a!!! R134a has a NARROW range of HI/LO pressure to work correctly. You could overcharge with R12, but with R134a the cooling will fall off and the compressor pressure will go UP a lot. On a custom system there are NO numbers to go by. What to do??? Charge R134a until the evaporator temperature won't drop further - THAT IS IT - STOP ADDING REFRIGERANT!!!!!! Crude but works.

Others with A/C experience are free to add or correct me!! No I AM NOT A BOT

Phil Dally wrote: ↑Sat Apr 12, 2025 3:36 am Vairy Cool!! (pun intended) How about a picture of the compressor pump?

not easy to get a good angle to see the bracket , the idlers are orig to the bracket. I plan on relocating the coil and wiring away from the belt.

Wagon Master wrote: ↑Sat Apr 12, 2025 6:30 am I'm trying to wrap my head around the amount of freon lines.
The evaporator drain I have figured out.

I can only guess that the original kit had a one size fits all hose assembly and the extra length was dealt with?
I removed the rubber hose assembly that was a few feet too long and building a copper line set to clean up the install.

[

The DRIER - Most designs have to sit verticle to work properly. FORGET the bubble port used with R12 - it is meaningless for R134a!!! R134a has a NARROW range of HI/LO pressure to work correctly. You could overcharge with R12, but with R134a the cooling will fall off and the compressor pressure will go UP a lot. On a custom system there are NO numbers to go by. What to do??? Charge R134a until the evaporator temperature won't drop further - THAT IS IT - STOP ADDING REFRIGERANT!!!!!! Crude but works.

Others with A/C experience are free to add or correct me!! No I AM NOT A BOT
[/quote]
On a custom system there are NO numbers to go by. What to do??? Charge R134a until the evaporator temperature won't drop further - THAT IS IT - STOP ADDING REFRIGERANT!!!!!! Crude but works.
Yes.

chief wrote: ↑Sat Apr 12, 2025 11:02 am
I can only guess that the original kit had a one size fits all hose assembly and the extra length was dealt with?
I removed the rubber hose assembly that was a few feet too long and building a copper line set to clean up the install.

CAUTION ! --- The LM (not sure on EM) systems used a copper pipe on the return LOW PRESSURE SIDE. This also made sure any liquid refrigerant would warm up and turn to gas before entering the compressor INPUT (liquid refrigerant ingestion is fatal to a compressor). The HIGH PRESSURE side of a system is usually by hoses rated to about 500PSI !!!

I can only see one hose fitting in you picture, but is is NOT the common Beadlock crimp fitting. Now with liner hoses (a must to prevent leaks) there are all kinds of custom fitting. I had great luck with the Eaton EZ clip used for busses and truck. Fittings have internal mini "O" rings, cut hose, slip on fitting, use a small clamp that is crimped with a tool the size of small pliers. NO LEAKS IN FOUR YEARS. See https://hosewarehouse.com/products/ff12 ... ment-blade

The Corvair used barbed fittings with a screw clamp and NON-liner hose. Unusual for GM (they typically used BeadLock), but with long hoses and tight spaces, AND very low volume, it probably made sense. Back then you usually had to ad R12 every year or two due to minor leakage.

Good luck with the job. There is a LOT of online information, but beware of well meaning, but incorrect information.

Gravity is something to think about as you consider a horizontal drier and condenser as gravity plays a role in both components.

In the condenser, gravity helps liquid refrigerant droplets pool at the bottom and that's where the outlet is located. Horizontal condensers are slightly tilted so the outlet is lower than the inlet. Horizontal condensers are practical if there's consideration is given to the relative "altitude" of the inlet and outlet.

After the condenser, final separation of gas and liquid occurs in the receiver. Gravity pools liquid refrigerant in the bottom of the receiver cylinder and the outflow pipe is submerged in the liquid. Separation of gas and liquid ensures only liquid refrigerant is sent to the expansion valve. Horizontal driers are rare and require specific internal pipe arrangements and orientation.

I made a handy-dandy diagram to illustrate my point:

Good post Craig. I know they make horizontal condensers, but they are built to work that way!!!

I've never seen a "horizontal" drier/separator, although some systems use a separate drier and separator. Typically the drier is more remote and the separator is close to the evaporator.

Again much appreciate the feedback and insight, the quest continues...
All of the rubber hose assembly is out of the car and the new copper line assembly is in place,the compressor is mounted. A new parallel flow condenser,and a stand alone receiver/dryer is in in the shopping cart,,,the evaporator and fan assembly is back in the car mounted on center from the dash. So now,inside the car, looking at the copper tubes emerging from the top of the tunnel a few inches from the expansion valve informs me I will probably modify the tunnel cover so the tubes can exit sooner and lower,to align with the evap core/expansion valve. I would like to get that plumbing done then go after mounting a condenser a drier in the engine compartment,,Oh boy!! more plumbing !! .
It is warming up outside here in North Texas.
Paul

Well you ignored my warning on using copper lines for the high pressure side. Also I suspect you will have use some hose from the copper pipe to the other components. Either a barb or some type of connector has to be on the metal pipe on the high pressure side.

Maybe some pictures will clear up my concerns.

I'm a bit baffled you did not want to use new hose as it is not hard to install and you don't have to CUT UP the tunnel.

I ALWAYS run the high pressure hoses OUTSIDE the car (as was done on the Corvair). I had a company car with the A/C working and the high pressure hose failed in the engine compartment while I was stopped at a light. Sounded like an explosion with lots of smoke. Folks called the police and fire department!!!!!!

Yea,a little while ago today I wondered for a moment why I didn't buy new hose or even reuse the hoses and fittings that were in place. Quicker and cheaper maybe? Then I remembered the messy hose install job that I removed. The high and low side hoses were in the tunnel, pretty well clamped in position but in contact with the throttle rod that is also in the tunnel (causing slow return to idle!). The hoses exited the tunnel at the rear through a hacked hole that has now been repaired.
The hoses entered the passenger compartment as seen in the picture posted earlier above. I did not like the install job and the hoses were too old to re-use. Copper came to mind and I had plenty of A/c copper .

Here I have to say that I did not know how the factory plumbed the lines,in or out of the tunnel, but I did consider placing the new lines outside of the tunnel,, I looked at the obstacles of that approach and the task of running them in the tunnel,,and went with in the tunnel.
I did not know I would be warned not to use copper pipe.
At the rear of the car the new line set exits the tunnel through the existing removable bulkhead that the shift cable also passes through, then the tubes turn and hug the floorboard to clear the park brake cable,the transmission mount and bracket, and the suspension cross member.The tubes are anchored with insulated clamps in and outside the tunnel and there are unions in place to allow removal of the line set or the complete suspension and power pack without cutting the pipes. No holes cut, nothing hacked. The low side has not been insulated yet.Pretty enough for pictures tho.
The engine and transaxle can be removed with out opening the system (theoretically)
The line set will have #8 and #10 o-ring fittings sweated at both ends to attach hose whips to connect the compressor and drier,,the evaporator has flare fittings, I am not sure how I will connect them yet, whips or tube.
And when I say the tunnel cover will be modified to allow room to make the connections to the evaporator possible, I mean the short cover inside the car next to the gas pedal and under the carpet.It will not be a hack job.It may be an all new two piece cover all shiny and such,but not chrome
I don't know how GM did the job back then on Corvairs,, so I will look at the service manuals to see if it is spelled out.
I know how my after market add on unit was installed about sixty years ago.
The 1964 service supplement appears to have the hoses outside the tunnel ,I wonder where they cut the holes needed to do the install.
I would like to look at an EM that has factory air to see.
Paul

O.K. chief - Thanks for the detailed response. You mentioned "A/C copper" which I assume is a high strength alloy. Note the HIGH pressure side working pressure rating must be about 500 PSI with a burst pressure of about 6,000 PSI !!!!!!!!!!

Glad you found the 64 assembly diagrams for factory A/C.

I AM NOT familiar with the EM A/C factory installations. Hopefully someone here is.

On the LM cars they ran the HIGH pressure HOSE outside the car along the rocker and up into the trunk were it connected to the steel evaporator inlet from the INSIDE car evaporator that protruded into the trunk. This ensured ALL high pressure hoses were OUTSIDE the interior of the car. The LOW pressure copper pipe return ran INSIDE the car, but had a hose connecting to the evaporator core (inside the car) and another hose from the copper pipe in the rear of the to the compressor inlet. The LM factory system used the flare fittings.

I installed the Clark's (Rusty's) serial/parallel bulkhead condenser that has the new "O" ring fittings. The Sanden compressor and drier used "O" ring ports. They do make "O" ring to flare fittings for hoses, but I looked a a number of different fittings. The old "beadlock" fittings require a HUGE tool to crimp. Some other styles were not commonly used. I finally chose the Eaton EZ clip fittings as they have been around for awhile and parts are easy to find. They work well with the "liner" A/C that is now about the only thing you can find.

BTW -- I assume your old system had R12 in it. When was the your Sanden compressor added??? For awhile you could order them for R12 or R134a - the only difference was the lubricant installed in them before shipment. Are you going to run the system with R12 or R134a? If you use R134a you MUST flush all old R12 mineral oil based lubricant out of EVERY part in the system. R134a uses a PAG lubricant that reacts badly to contact with mineral oil lubricants. Also Sanden recommds using THEIR modified PAG oil or warranty is voided. I have a table of Sanden lubricant numbers if you need them. Good luck.