Advice needed regarding non optioned A/C

[Lorne G.]

I have recently purchased a high optioned, numbers matching
67 big block convertible with correct factory A/C that was not an option for my car. The A/C was removed from another 67 vette that was totalled. The installation and all parts are perfect and factory correct.
I am planning on driving this car a lot and want a high functioning A/C system. I think my choices are:
1. Remove the non-optioned system entirely and install a new modern 134A system like Vintage Air that performs excellent.

2. Remove the A/C system form the firewall forward and adapt a Vintage system to the original vents and evaporator.

3. Convert the factory A/C somehow to make it perform stronger and with 134A cooling.

I welcome your feedback. Have any members gone through this before and what are the pros and cons of keeping this original system that is not correct for my car anyway.
Thanks
Lorne

[Jim K.]

Re: Advice needed regarding non optioned A/C

Lorne -
I don't know the right answer, but I would leave the factory (not original to the car) A/C in and try to get it working the best you can. My guess is that it will never be as good as modern, but you have it all and it's period correct. Save money and use it...
Jim

[Jack H.]

Re: Advice needed regarding non optioned A/C

Alternative 3 is not an alternative... If you simply 'convert' the factory A/C from using R-12 to R-134A refigerant, expect it to LOSE efficiency! Typically, an output loss in the range of 4F will result.

There are two issues with the factory original A/C in these cars:

(1) Gross temperature drop (the system is only optimum with R-12 refigerant) and what was designed and built was pretty darn good.

(2) Gross air flow...the ability to move large quantities of cooling air through the system to rapidly exchange heat. This aspect of all classic Corvettes is SIGNIFICANTLY inferior to what we're used to in today's modern cars. There's little you can do here AND preserve the factory originality aspects of the system.

There are 'band aid' approaches to making the system better that include:

(1) Change blower fan to force more air through the system.

(2) Change insulation below the carpet to decrease road surface heat migration into the cockpit.

(3) Tint the windows to reduce sunlight pervasion.

(4) Improve the cockpit seals to thwart air leakage.

But, even if you shotgun all four issues, the net results will NOT be equivalent to a modern era car's A/C system....

[Lorne G.]

Re: Advice needed regarding non optioned A/C

Hi Jim and Jack,
Thank you for your comments. It seems that even with a lot of band aid solutions I will only get minimum performance compared to todays A/C.
I am leaning towards pulling the factory A/C out, bagging and tagging it, and putting it away and drop a new Vintage air system in. I would leave all factory vents in place for the original dash appearance.
Lorne

[Jack H.]

Re: Advice needed regarding non optioned A/C

Here's an EXCELENT use for your NCRS National + NCRS local chapter membership dues! Before you decide that installing a Vintage Air system on your classic Corvette is going to give you the characteristics of a modern A/C equipped car, ask for someone in your local NCRS chapter who actually owns a car similar to yours with the Vintage Air system installed to take you for a ride and/or let you test drive the car. You just might discover that the basic characteristics of the car itself (see my prior post regarding floorboard insulation, cockpit sealing and blower characteristics) will prohibit achieving the efficiency level(s) you think you're going to obtain from the Vintage Air system repleat with it's modern Japanese compressor and R-134 refrigerant....

[Brian M.]

Re: Advice needed regarding non optioned A/C

I had my 67 out today for a 2 hour drive in 90+ outside temps. my system is stock and blows 39 degrees at the cented outlet. Works for me.

[Patrick H.]

Re: Advice needed regarding non optioned A/C

Hi Jim and Jack,
Thank you for your comments. It seems that even with a lot of band aid solutions I will only get minimum performance compared to todays A/C.
I am leaning towards pulling the factory A/C out, bagging and tagging it, and putting it away and drop a new Vintage air system in. I would leave all factory vents in place for the original dash appearance.
Lorne

There are plenty of old Corvettes with original systems that function entirely well, both on R-13 and R-134. Search the Archives if you wish for testimonials. It's only my thought, but if you remove it and install a Vintage Air, you're just going backwards. Now you have a system that anyone will know is not correct to your car and likely will function no better.

Get it running as well as possible with the original style system and R-12, or if you prefer use the R-134 refrigerant for cost and practicality reasons. I think that you will be pleasantly surprised how well it works.

My 71 and 72 Corvettes aren't as powerful as my 08, either, but they still go fast!

Patrick

[Loren L.]

Re: Advice needed regarding non optioned A/C

Some basic information is missing, ie 1> do you live in Death Valley CA or International Falls MN; 2> i'm not hearing ANYTHING about how the A/C on the car doesn't work - it's just not original; and so you're going to spend $$ to install a totally incorrect aftermarket system (no dig at Vintage, I have no idea how well their units work), please tell me why?; 3> you are the current "caretaker" of a desirable Corvette - use it and enjoy it....let the next caretaker worry about it.....
By the way, if this is the biggest problem you have with your Corvette, I don't EVER want to see you without a smile on your face.

[Don H.]

Re: Advice needed regarding non optioned A/C

I converted my '65 to 134 for one year, then changed back to R-12. As previously stated, I can hit around 40 degrees in the center outlet. I also agree with where do you live and what will be the usage. Bottom line it is your car, fix it like you want it, hopefully to drive and enjoy! Don H.

[Lorne G.]

Re: Advice needed regarding non optioned A/C

Thanks for the reality check guys, that's the very reason why I value your opinions.
Your reply already brought a smile to my face Loren.
My current system is not working and i was told it needed a new POA valve upgrade kit. Perhaps i should seriously consider repairing the current system, using R12, and perhaps Dynamat insulation under the carpet. I too believe that people would rather see an all original a/c system in a classic then a new modern system.
I live in Canada so there are not too many days I actually need the air on anyways.
Regards,
Lorne

[Jeffrey G.]

Re: Advice needed regarding non optioned A/C

I think you've got it, that's exactly what I would do!!!

[Larry M.]

Re: Advice needed regarding non optioned A/C

Lorne:

I would recommend that you keep the original factory system and R-12, and work towards fixing/updating it to work correctly. I think that you will be happier in the long run.

Regarding the POA valve. I would recommend that you try to buy a new or rebuilt POA valve; or, if you have an old original one, have it rebuilt. There are companys that can do this for a reasonable cost. I would NOT recommend a "POA update kit" that eliminates the POA valve and converts the compressor to cycling. These do not work as claimed. Since you are not overly concerned with originality, the second generation POA valve that was once available from ACDELCO/GM works like the original POA but costs less. They look a bit different, but fit and function correctly. New ones often sell on e-bay.

Good luck. Larry

[David K.]

[Kenneth B.]

Re: Advice needed regarding non optioned A/C

Thanks for the reality check guys, that's the very reason why I value your opinions.
Your reply already brought a smile to my face Loren.
My current system is not working and i was told it needed a new POA valve upgrade kit. Perhaps i should seriously consider repairing the current system, using R12, and perhaps Dynamat insulation under the carpet. I too believe that people would rather see an all original a/c system in a classic then a new modern system.
I live in Canada so there are not too many days I actually need the air on anyways.
Regards,
Lorne

Have you tried putting the windows & top down? My 67 390 air conv. with air blows cold enough to keep me cool with the top down but I live in NE Indiana not the south west. Keep it origional.
KEN

[Lorne G.]

Re: Advice needed regarding non optioned A/C

Thanks for the feedback. Now the hunt is on for an original or rebuilt POA valve. I will also consider the GM replacement version which is probably still available from GM if I come up short on the original valve.
Regards,
Lorne