AC upgrade on my '64

[KULTULZ]

The defroster is used to dehumidify the cabin air so as not to fog the windows. Later model cars are wired to engage the AC compressor with defroster selection.

As for cold outside air, the ambient air temperature switch will prevent compressor cut-in below a specified outside air temperature.

[Yadkin]

Dave, the modern compressor doesn't use the huge amount of power that the two-cylinder OEM unit did, so I don't think a power drain is such an issue.

An aside to that, since these are not daily driver cars, most folks don't worry about fuel consumption. I do, and I tell myself it's because I'm an engineer and want things to be efficient as possible, but the reality may be that I'm just a cheapskate. I asked my engine builder what he thought my fuel mileage might be, and his response was "are you kidding me?" My answer was "no...". It's nice to see that you and I are on the same page.

That being said, the way that NAP set-up the system, the temperature control cable was rigged to engage the compressor clutch, and nothing else. It doesn't connect to the OEM heat control door at all (since it doesn't use the old box). The way they set it up for me, slide the heat control lever to low and an electric switch opens a circuit, which is 12V and supposed to engage the compressor clutch. I think they wired it up wrong, confusing NC with NO. And, unless I'm missing something, the system has no way of controlling the amount of heat into the cabin.

In any even I'll throw that cable mounted switch away and mount a NO switch on my console. That way I'll be able to turn the AC on or off independent of the lever position. I'll then use the lever to control a cable to control a valve on the hose to the heater core. That should allow me to dehumidify and cool, dehumidify and warm, or just heat.

Last night I took the plunge and cut the box up.

[Yadkin]

Looks like I was wrong on something, NAP did give me a heat control valve for the hot water supply. I'll connect that to my OEM controller.

It's a complete kit but the hoses seem to be too short. They provide the cut hose and a variety loose ends, you choose which ones to use, assemble them and then borrow a crimping tool to complete the connection.

Unfortunately this set up requires the hoses to pass through the fire wall with the connections at the box impossible to get to, so to service the unit you have to disconnect the hoses at the compressor, drier, and manifold, then slide them through the passenger compartment still attached to the box.

Instead I'll have four hoses made to go from the box to four disconnect terminals at the fire wall, and then four more onto the system.

[simplyconnected]

...NAP did give me a heat control valve for the hot water supply. I'll connect that to my OEM controller...

I was concerned about that, otherwise you won't get much cool if cold air passes through a hot heater core.

Regarding your hoses; a good system will have hoses only in areas that vibrate. From your evaporator to your firewall should be hard lines. Personally, I prefer flared fittings because they are forever, they don't leak and they can be separated and reconnected any number of times.

"O" rings are easy and fast but notice, they must be nitrile (not neoprene) and they are the first thing that everyone changes when Freon leaks out.

Here's another thought... remember grandma's old refrigerator? You know, the one that was fifty years old and still making cold? It had a rubber-mounted compressor and NO HOSES. Instead, they coiled copper tubing and ran the pairs to the condenser and evaporator.

Modern 134A systems don't put out as much cold as R-12 but they also require less HP to put out less cold. The trend is to use Sanden compressors. They are piston pumps with a swash plate to regulate the stroke/pressure. Mustangs used vane pumps. The truth is, ANY pump must increase refrigerant gas pressure nearly 100psi more than the low side. This work requires ~3 HP (2,200 watts) in a good system. If the pump leaks pressure past the vanes or pistons, it must run longer to attempt the same work. Without high pressure, there will be very little cold as not much liquid refrigerant will flow through the orifice.

NAP's switch on your 'temp' cable makes sense; 'cold' turns the compressor on. Any other temp setting will not turn the compressor clutch on but will slowly crack the heater core flow.

Let's examine... That means your heater and your A/C will NOT be on together unless you have another clutch switch on the DEF cable. I would not throw the 'cold temperature' switch away but I like the idea of a separate toggle switch to shut the compressor off. Modern cars have them, too. - Dave

I still see no need for the heater core and evaporator should flow the same air.

[Yadkin]

Dave,

Thanks for your reply. That's an excellent idea, reducing the hoses. I think I'll run copper tube from the coil to the fire wall disconnects. That will reduce the possibility of a leak inside the passenger compartment. I'll also consider tube to the drier (in an insulation sleeve) and then to a terminal close to the compressor, then go with a short hoses for the remainder.

NAP had the heat control slide rigged to an on-off switch for the compressor clutch. Two problems here. One, the switch opened the circuit when slid to "min"; it should have been the opposite. Second, there was no cable to operate the heat control valve. Instead I'll use a switch to turn the clutch on and rig the cable to control the mechanical valve.

In this system, the heater core and evaporator are the same unit.

[Yadkin]

Gee, what's this little capillary tube on the switch that I was going to throw out? "Insert into evaporator fins". Guess it is to auto-cycle the AC and keep the evap from freezing up.

Oops.

[Yadkin]

Back at it, with the running body back, no doors, hood or fenders, last night I routed hoses, ready for a trip to King, NC hose shop to crimp them. Here's my routing plan. I'm keeping these out of the engine bay as much as possible to keep the routine maintenance items more accessible.

1. This is between the firewall and the evaporator (under the dash). Pardon my dust. The short black hose is the #10 return, The longer is the #6 from the condenser. The blue is one of the heater hoses. All four terminate in bulkhead fittings.
2. This is the engine side of the firewall. #6 above #10. The heater hose is the red cap, not yet connected.
3. This is the drier and condenser. The #6 aluminum tube has to be re-made since I kinked it. #8 hose is at the top of the condenser.
4. Passing under the frame, #8 below headed to the compressor, #6 passes between the control arms towards the firewall.
5. Here's the #8 passing behind and under the sway bar from the compressor.
6. Here's the #10 passing in front and below the sway bar on its way to the firewall.
7. Here's the #6 and #10 behind the control arms. I'll use several clamps to position these out of the way of the moving arms, and tight against the frame to pass behind the inner fenders (not yet installed).
8. Here's a critical point for the #10 hose behind the spring tower. There is a small space between the tower and the inner fender to pass through, and the big hose will likely get kinked here, so I'll use a 75 degree elbow here. The #6 will pass along side of it, then under the hinge ad to the bulkhead fitting.
9. Here's my duct taped version of the #6 hard pipe at the drier.

[Yadkin]

Yesterday I got the hoses crimped and installed them permanently.
1. New hard pipe at the drier.
2. This is the hanger that I came up with. It allows a tighter fit to the frame that a P strap. I found some heavy duty zip ties at Lowes electrical department, and use a #10 sheet metal screw to hold them in place. A rubber grommet keeps the screw head from abrading the hose. To remove it, cut the strap and use a new one.
3. No. 8 hose tight against the frame.
4. Plenty of room with the wheel turned left to its stop. These tires are larger than OE.
5. This is behind the tire, my first attempt. I hung the #10 house than zip tied the #6 to it. The tire rubs when full lock right.
6. My second attempt, hanging the smaller hose separately. The tire still rubs here, but only with the suspension fully unloaded. There's plenty of room at normal ride height. To be safe, I think that I'll make a steel shield here.
7. Tweaked the routing at the fire wall.

[HighwayThunder]

Belt problems with retrofit AC from CAA

I have the same CAA system as you and had to work through some problems with belt installation. Attached are the pics I sent CAA.

After some trial and error I determined that the belts that fit the 66 T-bird 390 application correctly are Duralast 15500 (large belt) and Duralast 15260 (small belt).

Cheers,

[Yadkin]

I had that same problem. To solve it I went with a serpentine belt system from March Performance. It requires a "peanut" Sanden style compressor, and puts it on the passenger side under the alternator. It's a neat configuration, which lead me to make it even cleaner by routing the hoses as I did. The only downside is that I had to replace my power steering pump with one off a Chevy.

[Yadkin]

Here's my shield for where the tire hits. First I chalked the hoses to see exactly where the contact was. Then I made a shield out of 16 gauge steel, dry fit it, and once I liked the position cleaned it and painted it with self-etching. I'll undercoat most of this area later.

[Yadkin]

An update on this. The little Nostalgic Air evaporator cools off the cabin, but I have several issues with it.

1. Noise. Even on low the fan roars. I wish there was a lower setting.
2. Defrost. There is a single cable operated air valve to open up the defroster or close it. There is precious little flow up there even when fully open. Also, my conversion to turn to AC on along with the heat valve on doesn't dehumidify much. I think this is due to a single heat exchanger in the unit.
3. Air flow between the floor and panel can't be controlled. About 95% of the flow is jetted to the floor and wears a hole in my leg. Turn these off and you don't change much.
4. On longer trips the outside of the case gets so cold, and the system dehumidifies so poorly, that I have to use a towel on the passenger side floor to mop up all the water. Thank goodness for the nice rubber mats that I bought from Macs, otherwise my carpet would be ruined.

[Yadkin]

In order to solve all this I bought a Vintage Air Gen IV kit. I talked with the manufacturer about my application, and he suggested that I get the kit for a 64-67 non-AC GTO. The factory non-AC controls are similar to mine, and therefore the conversion kit should work.

This evap box has separate heat and cool coils, so dehumidification shouldn't be a problem. The air controls are all microprocessor controlled servos like a modern car. There are separate valves for floor, vent and defrost. Supposedly infinite adjustable on all three plus on the fan speed.

The unit arrives next week.

[Yadkin]

Unit is in. HUGH improvement. The fan is quiet, the air can be controlled to exactly where I want it. I'll be testing my defrosters this weekend.

[stubbie]

Steve just looking at installing my Vintage Air evap box. I'm also keeping part of the passenger fresh air intake. Where did you install the evap box centre or passenger side of dash?