Im new to this forum but not new to owning corvettes. Is there a way to make a 1970 ls5 corvette's a/c work in a warm climate like south florida? my car has factory a/c and im going thru the whole car engine, interior ect. Im really not concerned with the cost, just want to go straight to what works. Could anyone with first hand experience list the steps to having the most efficient a/c system possible. Your help will be greatly appreciated.

 

I'd like to know the answer to that also.........

 

Any competent automotive AC shop can get your stock system running and cooling. R12 is still available.

 

Theyll make it run, but these a/c systems from factory were not adequate. there must be a way to effectively improve the performance to an acceptable level.[/B]

 

I've got factory AC in a 71 and it isn't enough to overcome the heat, I too live in FL...in Tampa - and it's WAY to hot for this car's original AC system to overcome. I've valved off my heater core water line, added the foil-based insulation (helps a lot), re-sealed my passenger side fresh air plenum, but despite this it is not enough to keep out the Florida heat.

From what I hear, the best option is to add "Vintage Air" or comparable, which costs about $1200 plus install and uses all the original controls and vents. I've talked with someone who had it installed in his car the last time I was at my local corvette shop and he said it works like a new car's AC...I was jealous, I want my hair to blow when I turn on my AC and instead I find myself sticking my finger up to the vent to see if I can even feel cold air coming out!

Here's a link where someone did it themselves...
http://forums.corvetteforum.com/c3-t...ir-system.html

 

Thanks, that may just be what im going to do.

 

Well, it wasn't any cooler in 1970 when the car was manufactured. And I can vouch for the fact that the Corvette A/C system did a fine job back then. I suspect there are many differences between your car [and its A/C system] now from what it was 40 years ago. If you were to upgrade all the influencing systems in your car back to original condition, it would cool the interior quite well.

 

I live in Qatar and temps will reach 110*F in mid summer, with the old A6 compressor and the stock condenser I had all sorts of problems, engine will over heat and A/C will not cool the cabin enough. Basically what I did was to replace the bulky A6 compressor with a much lighter and more efficient Sanden 508 compressor and used a much smaller but parallel flow condenser instead of the large stock one, the results were really good, the A/C is now freezing cold (although I'm using R134a) and engine will not run as hot as before.

I also found that I can now reach the #2 and #4 spark plugs much easier than before, that's a bonus!

 

I live in central Alabama and the temp in the summer gets in the upper 90's,..and even breaks 100 occasionally. Very high humidity and very muggy.

However, my 1976 cools great.

I did all the same things already mentioned, (put good insulation under my carpet, ,made sure my windows sealed corrcetly, sealed off any open holes in the fire wall, and made sure my A/C unit was serviced and operating properly. It actually got cold eniough that last July 4th, while on a local club cruise to Atlanta, I had to cut it down.

Take it to a reputable A/C shop and let them look at it.

 

But the SINGLE best upgrade is a parallel flow condenser, no matter what refrigerant you use.

 

It bothers me to think that i would have to remove the original evaporator if i go to the vintage or classic air system. It would ruin the original look of the engine compartment and make it seem like the car came without a/c. I would much rather at least try to work with the original evaporator. Changing the compressor and condensor seems to me wouldnt affect the original look as much. Is there a real improvement to be had from changing these two without changing the evap assembly? obviously with the other mods insulation, removing water to heater, covering holes ect. now is my chance the motor is out of the car.

 

The original evaporator is as good or better than any replacement by anyone.
The problem is the evap box sits close to the exhaust etc and is surrounded by hot air. You can insulate the evaporator box by various methods including coating it with a ceramic paint that will reflect heat and not look too different.
Helps to r&r it to clean it properly.

 

I did the dance with the factory ac for about 3 yrs when I had my small block in. I R&R'd the system and initially used R12....the system cooled well, I would get low 40* vent temps on 95* days here in Houston.....the problems I started having first was I could not keep front seals in the A6 compressors....I had two NEW(aka not rebuilt) A6 compressors on it, both blew seals within a year. Then I had a reman A6 lose a seal in two months. High side pressures were never over 280psi even at hot idle....other then that major issue, the system worked fine. The other major issue is that A6 compressor causes such a drag on the engine that it would definetly overheat in 20 mins of idling with the AC on....but the car could idle all day without AC....this was a stock small block, let alone a BB. Lastly with the big factory evaporator box in the engine compartment, there was constant heat being absorbed into the HVAC system and therefore pumping 110* heat into the cabin anytime the AC is turned off....(yes it was completely sealed).... Anyway I made it my mission for 3yrs, spent over $2k and ultimately, it was a waste.

Last year I did a BB conversion, switched to Vintage Air and I only wish I had done this swap 3 yrs ago....blows colder(38* avg), blows MUCH harder, doesn't drag the engine down near as much and doesn't kill off 3 mpgs....also doesn't seem to affect water temp at all. Lastly by not having the evaporator box in the engine compartment the system doesn't get heat soaked and pump heat into the cabin. Not to mention the engine is much easier to work on as there is a ton more room.

I know about wanting to keep the original look and all....I wanted that originally also, but as time when on, I really just wanted a system that reliably worked and was cool......

Do your research, search threads here....hell search mine, I have at least 4-5 ac threads here through the years and tons of pics/info on my VA install....in the long run, if you drive your car a lot and want it cool, VA is the way to go....good luck...

 

of all the vacuum operated vent doors.
I did a body off on a 72 LT-1 air-cond coupe. Found the floor vent door on the passenger side did not operate. It is normally closed in the MAX A/C mode to recirculate the cold air in the cabin. When I took the assembly out, I found that the vacuum line to the door actuator had been crimped between the assembly mount and the body. It never functioned since new! These doors are easy to check. You just need a hand operated vacuum pump to access the hose and check to see if they open and close. This makes a huge difference in cooling the cabin.

 

Your post is enough for me. Im going with vintage air. Thanks. P.S You wouldnt happen to own V.Air?... Just kidding

 

How about some more info on this mod. Any pictures?

 

Would love more detail of this approach.

 

I live in Tallahassee - and buddy it gets really hot up here.....
way worse then SFL !!!!

I have a completely stock AC system.
I replaced the drier and put a NEW compressor on the car. I had the POA valve checked as well all other parts.
It is charged with R12.

During the summer it will get my cabin nice and cold. It makes driving on the HWY nice. It works pretty decent in town, but HWY driving gets it a bit colder.

I made sure EVERY seal was replaced and every point that hot air could enter the cabin was sealed up during the restoration. The biggest issue is improper sealing. When the bodies were assembled the panels sometimes did not make perfect seals when creating the L/R plenum areas. As the cars get older, all the foam seals get dry rotted and break down. Something as simple as a missing the seal on the bottom of the heater core box (outside) where the heater hoses go up will through will allow tons of hot air in. There are lots of entry points that need to be thoroughly checked.

There is no denying that a BB will run hot (air on or off) - but you can get the AC system working 100% by spending some time.

It also helps to insulate the cabin from under car heat - specially the drive shaft tunnel.

my 2 cents....