Packard Forum Index » V-8 (1955-56)

Wonderfull looking car! The palm trees in the back creates a nice backdrop. Makes one think of Havana Cuba in the old days! Hahaha!
The black and white color scheme is really classy. You are an artist with the camera. Keep those pictures coming!

As far a the Packard getting the right screw, Should I put some Viagra in the oil first? but yeah I know what ones your speaking of..good catch

I moved the picture of the interior to the photo archive to save server space....I'll get a pic of the back seat for you randy next time I take her out.

at the risk of hijacking the thread, on the comment of needing to go to 12V to install AC - remember than Packard offered AC as a factory option on 6V cars. The only electical part in the system was the fan motor.

Could I find the Packard AC unit easily?

Also not trying to hijack this thread, but bkazmer said:
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<p>So how was the compressor clutch engaged? Or was some mechanical clutch used? Also, were there such things as low pressure cut-off valve, etc? </p>
<p>Just wondering... If this gets too far afield, it needs a new thread.</p>
<p>Craig</p>

I'm missing components (West has a complete sytem), but there is no clutch - the compressor is belt driven at all times. The air inlet is in the package shelf under the rear window. Admittedly the system is cruder, but it does make cold air. (and if you had the bar option, cooled the refrigerator - not a joke)

the Packard AC unit is very hard to find. What I'm suggesting is that a modern unit could work with only a fan motor swap to 6V if you are willing to use the concept of the original - no drive clutch on the compressor.

NICE, NICE, NICE.

That Packard really makes those PALM trees look good!

Seriously, classy looking machine.

You can be proud. (Obviously, you already are and it shows in the Patrician.

DanL

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Problem with the no clutch method is all modern aftermarket units, and for that matter, just about all modern AC units require the clutch to cycle to regulate temp to keep the evaporator from freezing solid. The operator controls a thermostat that engages/disengages clutch. The components to do any of the old temp control methods are as rare as complete Packard AC systems today.

In the 40's cars with always on compressor, a thermostatically controlled expansion valve was used to maintain a more or less constant temp above freezing at the evaporator. Air flow to regulate amount of cold air was the only thing the operator could change. For whatever reason, probably because it meant the compressor always had a load on it, & I've heard unless really hot, too little airflow with too much humidity meant it could freeze anyway, that single valve by itself was not carried forward when AC was available again in 53.

In the 50's cars with the constant compressor, the common temp regulation method Packard used was "hot gas bypass". This essentially was a valve which opened allowing the refrigerant to short circuit around the evaporator. One advantage with valve open was no load on the compressor. Disadvantage was a faulty valve could make diagnosing many other problems very difficult. Also, if conditions were right, the valve could allow liquid refrigerant to get to the compressor and resulting damage.

In 53-4 there was a regular evaporator valve to meter and keep from freezing but the bypass valve was an electric solenoid which was operated by an adjustable thermostat which was also electrically "adjusted". That plus the 3 speed blowers on each side gave the operator a fair amount of control over temp delivered. In 55-6 while the clutch did disengage when AC off, the actual evaporator temp was controlled by the evaporator valve and a fixed temp modulator valve at the output of evaporator which could sense and modulate or adjust for passenger heat load and again short circuited the refrigerant. Packard went back to the air flow only for any regulation on the operators part. Both these methods resulted in nicely & constantly dehumidified air with none of the moist blast of todays cycling clutch systems.

Other mfgs either used gas bypass or variations such as suction throttling, POA valves, or some other method of reducing refrigerant flow to evaporator. All methods (including Packards) essentially starving it to maintain temp. Temp control for others by the operator was by fan speed and the reheat method where the AC was at a constant temp but a variable quantity of air was passed over the heater coil to rewarm and mix to desired temp--again always dehumidified. The gas crisis and fuel mileage standards was the demise of constant on compressors.