Packard Forum Index » Post-War (1946-54)

Hello,


Has anyone air conditioned a 49 or 50 Packard? I am interested in knowing if this is possible and how complicated it is to do. Thanks for any help.

Richard

There have been several threads the last year or so on AC for that era cars. You can do a search of the forums for air condition, AC, etc etc. Basically the answer is yes---but can get costly and complicated. There were never any factory units so finding and installing one can be ruled out.

The mounting and style is not really a problem with an aftermarket unit as some will look older style and come with universal mounts. The issue is no one makes anything but 12v units anymore. The first choice would be do you want to convert to 12v or if not, what options you would have in powering it. Some have suggested dual batteries or 6/12v independent circuits. Both of those options get complicated.

Possibly you could you find an old 50's unit from a junkyard and it be made serviceable. With phase out and limited availability, the cost of R12 today and the certified person to install is almost prohibitive for a larger system. Makes R134 and costs of converting to use it look good. Converting an old unit may be an issue in itself, but in most cases doable.

Compressors are another issue. R134 with smaller molecules needs a good crankshaft seal which may not be available on an older unit. Actually, mechanical parts for older compressors are becoming hard to find. Some places do work on them however so depending on brand, all is not without hope. Depending on your engine, driving the compressor may be another problem since Packard didn't make an extra pulley available for the 356 crank. The prewar cars with that engine and AC used a pulley off the fan/waterpump. The other engines would require some changes in vibration damper but one poster has found some options there.

Most old compressors (if it is serviceable) of that era did not have a clutch or if they did, were not designed to cycle on and off frequently and that is what units today require for temp control--so another hurdle. The Sanden compressor would be the best option but again it is 12v. Some have said it MIGHT work on 7v--but I haven't heard if anyone tried. Even if it does, still the problem with a 12v blower motor. Some 6v heater motors are still available but not really powerful enough for the AC application.

My I chime in here I have a 48 Station Sedan which I have added AC. It has proven to be quite a project.

1st you need to decide what it will take to change the car over to 12 volts as no equipment is available for 6 volt. New alternator and mounting bracket, light bulbs, coil and change the starter over to 12 volt. If you have over drive you will need a voltage reducer to take care of it.

Next comes how to drive the compressor, as it is near impossible to find a 2-grove crank pulley that will work. I had a machine shop make a special 2-grove pulley for the alternator to drive the compressor.

Next is compressor mounting you will have to shop fab a bracket as no one makes one for the Packard 8.

Next is what kind of evaporator, under dash or behind dashes, just cooling or heat and cool. If you use an under dash unit, then what do you do about the heat vent controls. If you use a behind dash unit you have to remove the heater and use a combination heat cool unit and rework the glove box for clearance, which is what I did.

And now the biggest one is keeping the engine from over heating. The 48-50 Packard 8 engines are known to be subject to overheating. You will have to use either an under mount condenser with an electric fan or one mounted in front of the radiator then you will have to change the fan blade to a 6-blade high volume blade with an adapter and you may possibly have to change the radiator. This is the problem, which I am still working on.

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HH56, you are much more knowledgeable about these AC systems than I; however, I was under the impression that modern AC compressors do not cycle on and off to control temp, but run continuously when "On" and temp control is achieved by bleeding hot air from the heater. At least this is how I think the AC systems in my modern cars work. I believe earlier auto AC systems did throttle the compressor to control temp, but this method was changed to the more simple method of using the heater air. I have read in previous posts by others these same 'cycling to control temp' words and thought I would ask the question at this time. Just curious. Thanks.

(o{I}o)

The cars that are on the road today {in the USA} have a compressor clutch that cycles on until the pressure switch is satisfied, then freewheels until needed again. Often in 20-60 sec intervals. One could almost compare it to an engine cooling system with respect to the thermostat. Because the cycle begins, then ends heat exchange occurs, liqued to gas and vise versa, then cycles again for more of the same.

I've never run across a compressor that stays on all of the time, but it would seem like an unneccesary load on the engine during winter months.

It has been my experience that when converting from r12 to 134a you simply intall the very low cost adapters, less than $10 us, vacuum the system and recharge with 134a. It has worked 100% of the time for me.

Best of Luck !

Quote:

This is pretty much the way things have been since at least the early 90's and maybe even earlier. Lower end aftermarket systems used the clutch as soon as compressors became available with robust more heavy duty units but factory system cars up until the change did the constant on-reheat the cold air-style temp control. IMHO, that is a superior system as there is no humidity change as happens when the clutch drops out and suddenly thawing moist air is blasted into the car.

Mostly because of fuel economy numbers and trying to squeeze the last drop for the fleet averages, most US companies almost overnight adopted the cycling clutch. I am sure cost of components had something to do with it as well since the clutch system is much simpler with no POA or assorted similar temp control valves and plumbing to worry about.

Quote:

As to the R12 to R134 change, I'm glad you have had success but there is a big issue with oil compatibility. 12 uses a mineral base and 134 uses PAG or Poly Alkaline Glycol. The two are not compatible at all and mixing will destroy the effectiveness of both as well as prevent microscopic droplets being carried through the system to lubricate other items. Since the oil does pool in various areas, it is almost impossible to get it with vacuum alone. Usually a drain of the compressor and a system flush is needed as well.

134 also has different pressure and temp curves. While most modern systems are over-engineered and won't be too adversely affected, those with marginal condenser or evaporator capacity will be. Straight 134 is not as efficient as 12 so at equivalent pressures is about 10 degrees warmer but there are some approved products that can be mixed in to bring to almost the same level.

FYI, as long as you have an electric clutch, you can make it cycling or not, depending on the switches you use in the lines.

Car a/c systems are pretty straightforward and simple, once you understand the principles. When I worked for Salina Auto Parts in (where else?) Salina, Ks, I made several a/c systems for streetrodders, mainly just the lines but you still have to have all the proper fittings, bends, and connectors. It's pretty dang simple.

Very true and can be done. Two problems arise on early compressors--those with the mechanical clutch connections designed for an "on and stay that way" condition are not designed to catch the sudden load repeatedly and frequently & start to slip and overheat in some cases, or the mechanical links break in others. The other condition on early piston type compressors arises where the build up of high side pressure in the system averages when cycled off and then all of a sudden, compressor turns on and the piston has to move against it. If not designed for it, then a tremendous load is applied to piston, valves, and other components and something eventually breaks.

That's why you use a modern Sanden style compressor. It's smaller, so it fits in more places, and it'll do everything you need it to do. I'd avoid early compressors like the plague, as they take more power to run and are usually hard to find parts for.

Sanden is the way to go without question and I mentioned that would be the best option to the original poster. I have decided to replace my Lehigh with one--and maybe most of the entire unit with something else as well. More information will be coming if it works.

For those not wanting to convert to 12v or give up any outward semblance of originality or the era appearance, compressors become a problem. Almost everything else under the hood can be made to look appropriate but not a modern compressor.

As an additional question, I am wondering if anyone here has ever tried a Sanden on 6v. Specs say minimum clutch pull in is 7.5v but other car forums report some success.