Factory air conditioning system performance

[Biglione]

My car has had an engine and transmission swap, so it will never be a perfect original car. I am good with that. I am about to tackle getting the air conditioning up and running. The system appears to all be original, except the compressor, which is a GM style Frigidaire unit.

My question is if the original equipment system, in proper working condition, is a really good and cold system? Am I better off to work with Vintage Air to build a system from scratch?

Thank you

[jdsnoddy]

Since originality is not an issue, I would first try to repair/service your existing equipment and only start from scratch as a last resort.

[Biglione]

Thank you for your response. Could someone with an air conditioned Mark II confirm how well the original system works on hot days? What kind of temps can I expect at the ceiling registers?

Thank you

[Don Henschel]

In some ways John your response is somewhat meaningless and Normand your information is totally lacking ANY information! An engine and transmission swap tells us NOTHING! Swapped with what? A good used 368 and Ford O matic or a totally different make and model of engine?????
What are we working with here??
Depending on what you have and what little information you provided, if you are attempting to mix and match AC system parts, tell us what you have. If you have a GM Delco Frigidaire compressor, that throttling valve is nolonger needed and should be taken out and a thermostat switch is required.
Give us some details!

[jdsnoddy]

Beauty is in the eyes of the beholder.
I guess I misinterpreted the thread. I thought Joe was saying his car is a driver and he is ok with that. I thought he was asking if he should go to the expense of putting an authentic looking a/c system which would be built from scratch, on a driver car.
I had a Frigidaire compressor on my 1969 Chevy Caprice 350 V8 four barrel and it worked great.
I stand by my answer. Sorry you didn't appreciate it.

[Biglione]

My car had a 460/C6 power train swap from a 1973 Mark III. Other than that, I want to retain all other originality of the car and have plans to make it as nice as possible.

Because all original ac components are there, except the Frigidaire compressor, I wanted to know if the original system blows really cold air, when working and charged properly. Or was it marginal, and I'd be better off to do some hybrid of new components, while using original controls and ducting (trunk mounted evap).

[jdsnoddy]

Original Tecumseh/York compressors are old technology. Few are willing to rebuild them. And bc they have two valves, few know how to service them. Freon is now illegal in most places. If you use 134a your existing system will have to be rebuilt to accommodate 134a. It's a complicated issue which is an owner cost benefit analysis.

In my opinion, the original A/C system is one of the Achilles heel of the car. The nostrils take on water and the trunk mounted unit tends to overflow and rust the trunk floor.

[Don Henschel]

After reading other posts, I see you have a 460 Ford swap. The throttling valve is pretty much your only option to control the temperature because your evaporator unit is in the trunk behind the seat. A thermostat located back there doesn't sound very practical because of the location and the throttle valve is cable controlled from your heater/AC controls. You will have to get hoses fabricated or find a newer throttle valve assembly used with this Frigidaire compressor and they were even used up in the 1970's. Another reason why a thermostat switch or throttling valve is needed is you simply cannot keep the compressor running as is because the evaporator will eventually start to ice up. If too cold and you turn the blower down will make matters even worse. You don't have a blend door regulating the air flow either and that is used if you have an underdash unit along with either a cycling switch or a thermostat. Of course you could place a thermostat in the back but picture attempting to even try to adjust it!
In my opinion it looks like these attempted engine swaps are just opening up a big can of worms when your AC unit is located in the trunk and now your attempting to make something newer work with this older system. Yes the throttling valve was also used on newer systems with under or within dash systems as well. Instead of using a thermostat to control the temperature, the throttling valve recirculates the high pressure, high temperature refrigerant back into the suction low pressure side reducing its flow to the evaporator in the back to raise the temperature.
As for Classic Air systems, what are they going to attempt to sell you for an application with the large evaporator in the trunk?? Having a stock OEM power train and a car without AC and attempting to install AC from a wrecked Mark II sounds Ike less of a hassle compared to this!

[Biglione]

Hi Don, my original question was just to understand from someone that has an original Mark II, with AC, if the system blew cold, worked well, and was worth having. My car is a 1956, with factory AC, including the outside air intake system (scoops in quarter panels, with cable and knob on the package shelf). I have a complete original system, except for the compressor, which is frigidaire. If the compressor just pushes refrigerant, wouldn't the frigidaire work fine with the factory manual throttling valve? I also have R12 freon and access to gauges and a vacuum pump, so I plan to stay with R12. I plan to take the hoses that are there and have them remade, plus install new receiver/dryer(s), seals, o-rings and whatever I find at fittings/connections. I plan to pressure test too. Just trying to figure out after all of that will I have an AC system that works.

[Graham Rollo]

Joe my air cond which is factory, with the nostrils is very poor in blowing cold air due in part to engine heat coming from the hood & sucked into the nostrils, there is and article about this here, & the nostrils where abandoned think march 1956

[Milsteads Garage]

I install vintage air systems on stuff like Camaros Mustangs and Broncos. I’ve never installed one on a Mark II and that’s because even though the evaporator box is small, there is no good place to install it under the dash without seeing the box. Another thing you are going to have to do is mix and match parts to get it to work. They might have a bracket kit that bolts to a 460 but maybe not.

[Barry Wolk]

If you have an early car with intakes on the rear fenders the A/C is pretty terrible. That's why the vents went away. Elmer Rohn designed a work-around that eliminated the intakes and ran a tube through the rocker cover with flex pipe on each end to feed fresh air to the trunk unit. Morgan's right, there's no room under the dash.

[Don Henschel]

The evaporator unit within the trunk is anything but small. The Frigidaire compressor is up to the task but you cannot leave the compressor continuously running without some sort of a way to control the temperature of the evaporator. If it gets too cold and you don't have a throttling valve for recirculation TO REDUCE THE FLOW TO EVAPORATOR your evaporator can get too cold and if you turn the blowers to low it can and will start to ice up on the outside due to freezing condensation. This causes the low side pressure to get extremely low as well. Modern vehicles have a cycling switch that senses low pressure which occures when your evaporator gets cold and shuts the compressor off allowing the evaporator too not only warm up but also defrost as well and as the evaporator warms up the pressure rises and click, the cycling switch turns the compressor back on. Of course not only have they eliminated the thermostat using the cycling switch, they use an air blend door to allow warmer air to mix with the cooled air if you want to control the air temperature. YOU NEED BOTH!! My suggestion is look for a newer Mercury Marquis or Lincoln with a throttling control valve that was used with the Frigidaire compressor or attempt to use your Mark II throttling valve by getting hoses made up to connect it to your Frigidaire compressor. Since somebody decided to install a 460 under the hood means you will now have to figure out how to make this creation of a mongrel work!! There was an obvious reason why they used the throttling valve instead of a thermostat switch when your evaporator is in the trunk. How do you reach over and adjust a thermostat that has the sensing probe inserted into the evaporator fins when it's located in the trunk? An evaporator under the dash can easily have a thermostat switch but there is no room for one along with the blowers on the Mark II and is why it was located behind the seat.
Is creation of these mongrels such a good idea??

[Don Henschel]

If you have an early car with intakes on the rear fenders the A/C is pretty terrible. That's why the vents went away. Elmer Rohn designed a work-around that eliminated the intakes and ran a tube through the rocker cover with flex pipe on each end to feed fresh air to the trunk unit. Morgan's right, there's no room under the dash.
And it is totally beyond me why anybody thinks installing these stupid "nostrils" is such a great idea?? Cooling was lousy and when driving in rain, the wind driven rain gets forced into them as well.