I recently completed my VIR eliminator and Air conditioning upgrade to my early 77 model that came factory with the Valve in Receiver style air conditioning system.
My story begins about 17 years ago when I was living in the Milwaukee area. My then Wife had a late build 77 and her air-conditioning wasn't working. We had met a guy in a pub who claimed he could convert it to 134 and get it up and going for a very low price. So we thought, let's give him a shot.
Well, for a low price he did indeed get the air-con working fairly well.
So my early 77 was at a point where it was due for a recharge. So I gave this guy a try. Mind you at the time I had zero knowledge of the differences between the 2 cars air-conditioning systems. Well, it had 134 in it. And it sorta blew cool air. certainly not cold, but better than nothing.
It was then I learnt about the differences in the systems.
So, fast forward to a year ago. I live in tropical Queensland Australia. Gets bloody warm here and C3's are not the coolest cars on the planet in the interior at least.
I had for many years been wanting to upgrade my air-con so it would work properly. And getting R12 in Australia just isn't a option. So I did a fair amount of research. And please keep in mind that although many swear by the Vintage air conversion. This was way out of my budget. I had to save up a long time to do this. And my HVAC controls and all my actuators and doors work fine.
So my system looked like this last March.

Through all my research I learnt about the limitations of the VIR system and decided to go with a VIR eliminator kit.
Also almost everyone on the web recommended changing out the original compressor with a Sanden unit. I needed new hoses for certain and my compressor was the original 45 year old unit. So that made perfect sense to me. Also on the list of upgrades was the condenser and the accumulator. Most VIR eliminator kits will come with a accumulator so that was easy. And most people out there highly recommend changing out the factory serpentine condenser for a modern parallel flow condenser.
On this forum, a member recommended a company in Florida that sold a complete kit , compressor, hoses, mounting brackets for the compressor, VIR eliminator and accumulator with a mounting strap . Basically everything you need to convert properly for one low price. With the exception of the condenser, Which they sell separately for a rather high price. I decided not to purchase their condenser.
So I tryed to contact this company in Florida. No, they don't answer their Emails. for a couple weeks I sent several emails. No reply. I then found a contact for them through Facebook messenger. And low and behold. Someone finally answered me. As I live overseas I did not wish to simply order off there web site as it wouldn't give me a overseas shipping quote. I needed to know. I should have moved on and found another source for these parts. Hindsight is always 20 - 20.
So, to insure that they got me the correct parts, they asked me several questions about my car, twice mind you. Even though my car has the original engine and 77 models only came with a small block V8. I answered all there questions and placed an order for their kit.
I also on the recommendation of another forum member started looking at parallel flow condensers on ebay and Amazon.
I ended up ordering a universal parallel flow condenser that was almost precisely the dimensions of my original condenser.
the condenser showed up in about a week from the States.

I painted it black. as it was shiny aluminium. And mounted the brackets off of the original to it using some small strip's of steel and a few small screws.

And mounted in my car.

All this while waiting on parts from the company in Florida that sold me my kit.
About a month later I finally received the first box. in it was a compressor, Some hoses with no ends on them and a bag of fittings. No compressor brackets or O-rings or accumulator. They were to be in the next box.
So I thought while I continue to wait I would paint the compressor to match up with my engine compartment.
Little did I know at the time, but they should have sent me a compressor with the fittings out the back, not out the top like this one. If you are going to do this on your small block, try to get the compressor with the fittings out the back cover.
Still waiting I removed the original VIR assembly.

Looking up from underneath, most lines where easy to remove from underneath.

Here it is on the floor, note the hose that goes to the compressor I just cut off. That upper fitting is hard to get to. And new hoses are going in anyway.
Well box 2 finally shows up about 3 weeks later. with the rest of the kit. However, they never did send any O rings. those I ended up ordering a kit off of Amazon even thou my kit was supposed to have them. Oh well, that was minor. Now I had the eliminator that holds the orifice tube, the accumulator and....... The wrong compressor mounting brackets! They sent me mounting brackets for a big block car! after all the questions it turns out that the compressor they sent was also ment for a big block. So, contact the company again. Getting an answer takes days. finally they get back to me. They have no small block mounting brackets and they are waiting on them from their supplier.
While waiting on compressor mounting brackets I thought in my spare time I would move forward and get the VIR eliminator and accumulator in place.

The instructions were as clear as mud, but doing a bit of looking around on the net I was able to get it in the proper orientation. Not bad at all.

These are fittings I never used. the funny looking pipe on the right the instructions say to mount on the bottom of the accumulator before installing. Then connect the hose to the compressor to that pipe. I decided I didn't need an extra unnecessary connection. And simply ran the hose to the bottom.

Accumulator mounted in place where VIR once lived.

Looking up from underneath. Note how I just ran the line straight to the bottom. Very easy to get to.
well finally I got the correct compressor mounting brackets.

Mocking up the brackets.

Mocking up the hoses, note they are not crimped yet. try as I might I could not find a fitting for the hose that goes to the condenser that didn't have a valve on it. and I had to have that curved fitting thanks to the fittings up top like that.

All mocked up, off to the air-con shop in Cairns Australia to get all the ends crimped.

Ends crimped and valve removed, not happy with the look of the weld repair, but was worried about the valve contacting the hood.
Next was the trouble with the belt and the connection to the bottom of the condenser.
The instructions in my kit gave no clue as to which belt to run. It came down to, Let's try this! Nope, return that one and order this one, Nope? Return that one and order another. about 4 or 5 tries. I came up with a 11A1460 but because I have a Spreader bar. another issue was raised.

Belt narrowly missing spreader bar bracket.

Spreader bar bracket modified. Hard to see in photo but it has about 1/2 inch clearance. wish I had more but next shortest belt I could find wouldn't go on.
lower condenser fitting clearly wasn't going to fit up with factory lower line. Line separates at the low pressure switch block on the right hand inner fender. Air Con shop made me up a line. About 35 bucks.


Last thing was wiring up the cycling switch mounted on the accumulator. Instructions were once again clear as mud. I tryed contacting the tech support at the company in Florida that sold me this stuff. Total waste of time. Found a fair bit of miss information on the net. And some correct information. the kit included this.

But really didn't explain how it should be wired.

Correct way, cut the wire heading to the factory low pressure switch. Splice in the wires for the cycling switch so power goes through the cycling switch and then on the the low pressure switch.

Looks like this after a tidy up. I should add that my air-con professional that helped with the pressure testing and gas charging highly recommends that I replace the factory low pressure switch on the right hand inner fender,

This one hiding behind the radiator overflow hoses. With a trienary switch. Cuts compressor clutch if pressure is low, like the stock switch, cuts compressor power if pressure is too high. and the third function is to power up fan relay once pressure hits a certain level. As my fans now run only on engine temp, controlled by my EFI ECU. that sounds like a very good idea. I have said 3 way switch on order.
Then lastly connect wire from low pressure switch on the right hand inner fender to the compressor. I decided to put on a nice weather proof connector.

And finally, vacuum the system, pressure test and charge with 134. check for leaks and adjust the cycling switch.

And believe me, It's like a bloody refrigerator inside my car now! Lot's of dramas getting the right parts. Finding fittings because supplied one's were wrong. But in the end. My budget system blows very cold air. 5 degrees C. at the vents.

 

Very informative thanks for the great information

 

ok, yours is built but some may find this thread for reference. some have issues with the hoses going straight up off the universal style Sanden head. this cyl head fits the GM A6-R4 hoses. https://www.partdeal.com/omega-sande...MaAkqHEALw_wcB and the replacement hoses are cheap..55 bucks a set and the hoses folow the orig path. you just have to be sure you have a 5 or 7 cyl compressor. 5 or 6 bolt pattern.

 

Thanks for that Derek. None the less this thread is for those with the dreaded VIR Air-Con system and how to upgrade to get modern Air-Con performance without the big bucks of Vintage air.
In no way can the stock hoses be used on a 73 - E77 VIR eliminator set-up.
Although those with a 77L and up system just looking for a compressor upgrade might like the compressor cover you show.
I did in my first post mention that the Sanden compressor can be obtained with fittings out the back and that is what they should have sent me. Myself being on the other side of the planet dictated that I made the wrong compressor work as the cost of shipping alone would have killed the project.
I am not a wealthy man.
Almost if not all VIR eliminator kits come with the hoses that just need the ends crimped on. and of course the modern Accumulator would never accept the factory VIR hose anyway.
And yes for a kings ransom you can get a parallel flow condenser that will hook up to stock lines. But as I already said, these VIR kits come with hoses that just need to be cut to length and crimped. The Air-Con shop in Cairns (when I started this project). Charged me zero cents to crimp my hoses. The custom liquid line I had made up from the condenser to the fitting on the right inner fender cost me 35 bucks in Australia. (about 20 bucks U.S.) That's fittings, hose and labor. compared to a direct fit condenser that was hundreds more than the universal condenser.
So. No I can not see any benefit to purchasing a new head cover to mount stock lines when on a 73 - E77 VIR elimination/ 134 conversion. the other ends of the lines wouldn't work anyway. And custom lines are also cheap.
As per stock routing. I intently moved the line from the accumulator to the compressor as with the factory routing I once blew a line as the factory has it way to close to the exhaust.
Stuff the factory routing.
My next post will be about the finishing touch. installing and wiring up the Trinary switch. A most important thing with my electric fans and this modern setup.

 

i also did my own VIR eliminator by buying a 78-later evap and accumulator. now i need a liquid line cuz my idea of splicing it didn't fly. i am pretty sure the compressor end of those hoses is the same for A6 and R4 compressors the firewall end of the low pressure return line is diff from VIR to later orifice type. and the hose set is 60 bucks. a 5 cyl sanden knock-off is 50 to 100. 30 more for the Q (GM) cyl head 65 bucks for the evap and i found correct fit parallel flow condenser for 100. so this is vintage air without the markup and using your ac box, controls, ducts...

 

O.K. So. thought I need to add this bit. Seems none of the VIR eliminator kits are very clear on the wiring up of the cycling switch and whether or not to wire in the factory low pressure switch. Or what about a binary switch or Trinary switch.
I searched the internet. I talked with a couple different Air-conditioning specialists in 2 different cities. Both older businesses with old guys like me running them with years of experience.
Lots of misinformation on the internet. And some good. But how do you know which is correct.
I'll make a long story short. I learnt the hard way real quick if you don't have a high pressure cutoff switch. things blow up!
When upgrading to a VIR eliminator and 134. you are changing things up to a more modern system. And the cycling switch mounted on the accumulator isn't designed to handle the issue of high pressure in the liquid line.
So. Our factory air in 73 - E77 cars are equipped with a low pressure switch only. Most modern cars have a High - low binary switch. Also most modern cars run their electric fan or fans off of the ECU. which knows when your air is on and runs fans accordingly.
O.K. so the issue is. if you turn on the air when you first start the car. With electric fans run off of a thermo switch. Your electric fans are not going to run until your engine temp reaches the set temp of your switch. In my case I run my fans off of my EFI ECU. However my EFI is a very basic set-up with no input for Air-conditioning. So it's basically the same other than I can adjust the temps the fans come on and off.
But the engine temp works great for the fans to keep the radiator cool. The condenser in front of the radiator needs to be kept cool as soon as you turn on the air. If the car isn't moving or moving slowly with the air running and no fans the high side pressures will build through the roof as the condenser can't transfer the heat.
So. We MUST upgrade that factory low pressure switch to a binary, (high / low) switch if we are running a mechanical fan. Now with the mechanical fan running all the time it's not likely to be an issue. But it's still safer to have that high pressure switch. With aftermarket electric fans. A trinary switch is important as it is a High / Low switch and it grounds the fan relay at about 220 PSI. so basically as soon as the system starts to build pressure, it kicks on the fans. Often long before the engine temp sensor would have.
These binary and trinary switches are available from Amazon, ebay and most auto parts stores. The issue I found was finding a switch that fit my factory high side line.


As you can see in the above photo a adapter fitting was necessary. I got this adapter fitting at a specialist hose shop. About 4 bucks.
Installed to my liquid line.

And wired it in. All of these trinary switches have 4 wires. some will have 2 black wires and 2 blue wires. this one a red wire. (power in) Black wire (to compressor clutch) and the 2 blue wires. one to ground, the other to the fan relay. the same terminal that connects to your thermoswitch.
Wiring in this switch in series with the cycling switch on the accumulator.

Sort of like this. Add in the blue wires for fan control if trinary switch of course.
Once this is done. your compressor will stop running if you run out of freon (have a leak) will shut down the compressor if pressure gets to high. And of course the cycling switch will cycle the compressor to keep evaporator from freezing. And with Electric fans the trinary switch will run the fans like a modern car.
This one switch is overlooked in all the VIR eliminator instructions. Yet every air conditioning specialist I talked to claimed it's absolutely necessary.
As for my car. My first try at running my system blew the line between the compressor and the condenser because my fans weren't running. After talking it over with a couple different Air-conditioning guys. everyone agreed that it was strange that the factory did not have a high pressure cutoff switch. Now that my car has one. No more troubles.
Just cold air.

 

I ended up doing a roll-your-own conversion on mine because the PO had yanked out everything except the evaporator and VIR. My setup is very much like yours now - stock evaporator, accumulator, sanden style compressor and parallel flow condenser.

Your thread is much appreciated, it confirms a lot of what I installed. The only piece I don’t have is the binary switch. (I have electric fans that kick up to high when the compressor turns on, but I would be open to rewriting for a trinary switch.)

I have a couple questions:

-Do you have a link or part number for the switch you used?
-What line did you install it in? Compressor to condenser line, or condenser to orifice tube?

thanks
steve

 

Sounds like even all your lines were pulled out. My photo is pretty clear. you remove the factory low pressure switch located in the block that has the high side pressure valve in it on the right inner fender just in front of the coolant overflow bottle.
Now, if you no longer have that factory switch location, you can get a splice in switch block. Once again, Available everywhere. I am guessing when you said the previous owner pulled out everything. he also pulled your liquid line.
The switch goes in the high pressure, or liquid line after the condenser.
l'll see if I can find a photo of a universal switch block setup and post it up.

 

Something like this can be added to your liquid line.

 

Yes, all the lines were gone. I had to fab up all new lines.

The photo and description are just what I needed, thank you.

 

Had a little time this morning. We hooked my car back up to the gauges to check operation of my system.
Happy to report that Trinary switch is working perfectly, high side pressure builds to about 240 Lbs. fans kick in. pressure starts to drop. Fans kick off at about 220. Cycling switch is operating the compressor clutch as it should, everything is working like a modern system.
And BLOODY COLD AIR!
If you have a VIR System and are thinking of upgrading.
Do it right. You don't have to spend the big bucks of Vintage Air. And you can keep your fresh air vent and have cold air.
Cheers Guys.

 

Thought I'd re-visit this thread and add just one more thing.
I found on real long drives. More than 100 miles. My evaporator was icing up. Seems the pressure switch that cycles the system based on pressure alone is a bit less than accurate.
This I have learned is why no modern system is using this anymore.
I installed a adjustable temp sensor switch with the tip of the probe right on the pipe just as it enters the evaporator box.
These adjustable switches are available at most automotive parts houses and of course on line. Very inexpensive.
I simply unhooked the wires from the pressure switch on the accumulator and connected them to the adjustable temp switch.
Before installing the switch on the car I put the probe in my household freezer with my digital thermometer. And got it set to trip at 34 degrees Fahrenheit.
No more icing.

Not the clearest photo, but about a third of the way down hiding in there you can make out the adjustable switch with a bit of silicone on it to prevent it from turning now that it's adjusted. Near the bottom of the photo just right of center you can see the pipe dope on the inlet pipe into the evaporator. And you might, maybe, make out the thin tubing to the pipe dope that is the lead to that temp probe.
I guess this is all to say that these VIR eliminator kits are imperfect. But they are a start.
With the temp switch instead of the pressure switch. And the installation of a C4 blower motor.
I think I have air-con that rivals my modern cars.
Cheers guys, hope all this helps.

 

Advantage over modern cars. Nobody in the back seat complains cuz it isn’t cool enough.

 

Ttt