64 - Rebuild Stock A/C or Aftermarket

[64Rivvy]

Just looking for some opinions on this.  Should I rebuild my stock A/C system, or go with an aftermarket system like Vintage Air.  I have a VA system in my 69 camaro and it's pretty good but a bit clunky.  Can't see it cooling an interior almost twice the size, but I assumed they have a bigger unit.

 

Just about all of the existing stock system is there, but all the big components need to be replaced (condenser, evap, compressor rebuild, drier, heater core, vents).

 

I am leaning towards rebuilding the stock system and installing the mod that runs the compressor/clutch only when needed to offset the horespower the stock compressor steals running all the time.

 

What do you guys think?

 

Thanks.

[alini]

The stock compressor should still be cycling on and off, not run all the time when on.  So you shouldnt see a difference in that.

 

The ultimate question is in your hands, it depends on what you are doing with the car.  Do you have a stock car and want to leave it that way?  Many purists will promote that as the factory system was efficient enough for the car, parts are available and nothing beats an original car.

 

Others will say R-134 is safer for the environment, these systems can be more efficient overall and lighter.  But putting in a VA system will require alot of modification (fitting plates in the firewall, mounting the components)

 

Cost wise its really about the same.  Having put a VA system in my car, it cost me about $1100, but I did all my own install.

[64Rivvy]

I thought I remembered reading something about the stock clutch always being engaged on these older units and there was some sort of valve mod/kit that needs to be installed to make the compressor operate more like a modern day compressor.  If that's not the case, good, one less thing I need to do.

 

Raul

[alini]

Just checked the book, you are correct the clutch is engaged all the time, but the compressor being a swash plate design only produces pressure when needed.  Unlike current designs which engage the clutch when its needed.  So the draw when not compressing is a drain on the engine its not as much as when compressing.

[JZRIV]

Search function to the rescue. Read the whole thread. It should help you decide what's best for you.

http://forums.aaca.org/topic/115312-vintage-air-ac-conversion-for-1st-gen-rivieras/?hl=vintage#entry1109770

Mike Middleton did an outstanding job not just on the install but documenting it in detail the work required for a VA system on Bill Stonebergs car.

After reading the complete thread, installing the VA system requires a lot of labor and if you are doing it yourself you'll need above average skills. A stock R12 system engineered to the car can't be beat IMO. I have totally rebuilt stock systems on 66-67s and while its a lot of work and maybe around $1200-$1800 just in parts and rebuild/test services, I'd rather do that than the conversion after reading the thread above but I am used to dealing with stock systems of the 60s.

Food For Thought: When rebuilding a stock system from the ground up folks with basic mechanical skills can save a lot of money by removing all the main components and replace with new or pack and ship originals to Classic Auto Air in FL for rebuild and testing. Once all the parts are rebuilt or obtained, they can be re-installed and a competent A/C shop can do final leak testing and charging if you don't have the ability or tools for that part of the process.

As for the Suction Throttling Valve (STV) eliminator kit that essentially uses a thermostat to control evaporator pressure by cycling the compressor clutch on and off like modern cars. Some have been happy with this conversion but a cycling clutch in hot weather is not as comfortable as the stock setup where the clutch is always engaged. Note the A6 compressor clutch was not designed for frequent cycling. Maybe its over engineered enough to hold up or maybe not. I don't like cycling clutches even in modern cars designed for it. Compared to a malfunctioning stock STV valve system, the cycling system is great. But compare it to a properly functioning STV the cycling system loses....just one opinion. Converting the STV to cycling clutch system sacrifices some performance but on the flip eliminates cooling failures due to the STV which is probably the weakest link.

Edited October 27, 2015 by JZRIV (see edit history)

[Bill Stoneberg]

Mike is a perfectionist and it shows in his work. No matter which way you go make sure to replace the weatherstripping. No matter how cold your car is, if you are blowing hot air in the car, the Ac system can't keep up.

[64Rivvy]

Thanks for the info and link.  Definitely a lot of good info there.  I have replaced some of the easily removable weatherstripping already and will be replacing all of it when the car is repainted.  

 

I'm leaning towards the stock system, just worried about chasing gremlins b/b there's so many more variables that can go wrong.  I'll let you all know how it turns out.  I'm going to start on this when my new radiator comes and just replace the radiator, condensor, drier, water pump, thermostat, and transmission cooling lines, all in one shot.  

[Bill Stoneberg]

Living in Texas I removed the STV and added the cycling feature before removing the whole system.  I ignored the cycling part though and just had the compressor on or off.   If the cabin got too cold (no chance) my pans were to open a window of have my wife put a blanket on.  Never happened though.

 

I have to say a proper functioning A6 Compressor can make it cold enough to hang meat. They produce more cooling capacity the a window A/C unit in your house.  Whoever designed it did a good job.

Edited November 1, 2015 by Bill Stoneberg (see edit history)