What year cars to salvage A/C system for a '71?

[archtech]

I'm looking to put A/C in my '71 and would like to know year 911's I can use to get parts from to put together an A/C system. I've got a factory underdash vent part with switches, but my smuggler's box is completely empty. I've heard that older A/C system hoses leaked freon, so what year system should I be looking for?

thanks!

[kuehl]

send pm and we'll give you a list

[JohnJL]

I have a pump, all the condensers/brackets/fans/evaporators/controls and hoses from am 83SC for sale. The hoses need replacing but you'd have the originals to use as templates.

[Jim727]

I did exactly that some years ago. Ideally, you are looking for a '73 or '74 (maybe '75, but I'm not sure). When I did mine I went to European Auto Salvage Yard in Emeryville and they let me pull the parts I needed. That was a very good thing, because nothing was left out and I could see the correct order of things as the factory built them. There are several things you will need and several you will want to use only current components for.


Duct:

The one component most visible is the Behr under-dash a/c distribution duct. It looks like you already tried to get the correct one on FS: 1969-1973 Factory Under Dash A/C Unit (Behr)

Last winter I upgraded the fan speed controller in the Behr duct with Griffiths Variable Speed Fan Controller. The stock fan controller might as well have been an on/off switch - Griff's controller is an outstanding upgrade, though I couldn't get the led to work as desired probably because I don't want to put a hole in the duct - but one you want to do early when the duct is out of the car and accessible. Once the duct is installed, it's a pita to have to remove.


Hoses:

Think new here. Our host carries barrier hoses. Don't even consider original hoses. You also need to decide on the type of fittings you want to use. The original fittings used a copper crush washer and the new fittings are o-ring.


Condenser(s):

Serpentine, when available, is better than factory tube/fin. O-ring fittings are better than compression fittings. Best to have them the same throughout, if possible. You will need an engine-lid condenser and a front condenser. The front is readily available as a serpentine condenser; whether you want the desert-duty front condenser is a matter of choice and of how the car is set up. There is a very comprehensive a/c thread which is a must-read at A/C Upgrade Project starts tomorrow! - be sure to check page 5 for issues regarding the deeper desert-duty condenser. For the engine-lid condenser, you probably will have to go tube-and-fin, though three-row condensers can be found (don't recall where right now). Make absolutely certain that you properly support the fittings and have hose supports attached to the lid hinges. If you buy a used condenser be sure to check the condenser tube-to-fitting area to ensure some gorilla didn't give it a twist. These need two wrenches to work the hose fitting; use just one and it can badly mess up the condenser tubing.


Evaporator:

I went with the Griffiths serpentine evaporator because it appears to have a greater heat transfer area which I wanted. I have to tell you it's a work of art - I hated to close the evaporator box. Griff's aviation experience really shows in the quality of this part.


Receiver/Dryer:

New. Don't even consider a used one. I went with the Pro-Cooler. There is also a good thread here on a subcooler at A/C Subcooler Information


Compressor:

The biggest you are likely to get into a '71 is the Sanden-507.


Wiring:

If you can pull the harness from the donor car it will make for a much neater installation. Pulling it yourself or having pics of the process will simplify the task.


Everything Else:

Other bits you will need include
Crankshaft pulley;
Engine mount;
Engine tin near the mount;
All the mounting brackets to support the compressor mount. Be aware that some of the aftermarket a/c kits attached to the chain housings - guaranteed to produce engine problems. You want the factory ones that attach to the engine mount and cam tower;
Updated compressor mount adapter for rotary compressor;
Front condenser fan and air box;
Updated in-line fuse for front condenser fan (911.612.077.00-0A);
Evaporator box with fan (Griff seems to have a new fan motor available);
Patience.

There are several threads on getting this done. Which brings me to: "Search". Two names to follow are Jim Sims and Kuehl. Always great info. A good starter thread is at Obligatory 32F AC vent image

You don't say whether you have a T, E, or S. There are clearance issues with the compressor. If it's a T the Zenith carb throttle return spring attachment point will have to be moved. Biggest problem in fitment is the oil filter console - couldn't be in a worse position for clearance. I had to customize the mounting plate on my compressor to make everything fit, but in any case you will have very little adjustment range.

You have to cut a hole in the pan in front of the spare tire to mount the front condenser air box. This also requires removing and relocating the windshield washer bottle.

Wiring was not the factory's strong suit, but having an original harness will make life easier. You will have to commandeer two fuses for power. There is a relay in the factory harness that switches power to the front compressor fan, but no fuse - that's what the updated in-line fuse is for. Unfortunately, I've been having problems with an overheating relay in the smuggler's box with associated blowing of fuses. Last weekend I did some tracing on the circuit and noticed that the compressor clutch is powered directly through the cockpit a/c switch (sound familiar?). I ordered another Wehrle relay from our host and spliced into the front compressor fan in-line connector to use that as the control circuit for the new relay which now fuses and powers the compressor clutch. You will have to run a wire to power the compressor clutch - through the tunnel works best.

I did not go with any fender-mounted condensers mostly because keeping the car visually correct for the period is important to me. So far, I have been very happy with the system, though since my latest upgrades I haven't had to test it on a very hot day. There is nothing in the process that is massively difficult, it's just a time-consuming job that rewards attention to detail. For me it was very much worth the work or the 911 would end up parked through the summer or only driven at night.

I know this is a bit rambling as I didn't document the process when I did the install and it was from a time BDC (Before Digital Cameras) so no installation pics but I think the main points are here.

Jim