X1/9 AC Restoration and Upgrade - What the wife wants, she gets

[LarryC]

Recall that this project was started last August when the wife requested that I tackle the X1/9s AC and get it going again (http://xwebforums.com/forum/index.php?threads/18173/).

But was interrupted by Fall and by a heater/AC blower motor that required rebuilding.
http://xwebforums.com/forum/index.php?threads/20043/

This turned out to be a good thing since the AC-Heater box resulted in significant clean-up and improvements in the efficiency of the air inlet system overall. But it was a big project and I used the winter to do it. But if you can, this is definitely a good idea since the box was pretty dirty, the gasket that forces air through the evaporator was crumbling, and the fresh air door was stiff. Now that part of the system is factory fresh with a new expansion valve and other goodies.

At the same time I continued to collect some of the parts necessary for a thorough rebuild of the AC system. This included new 134a barrier hose after determining the lengths and sizes required to replace the original hoses. You can re-use the old fittings if you are possessed of sufficient time and shop equipment to restore each for crimping on new hoses. But the X1/9 uses standard beadlock O-ring hose fittings in hose sizes 6, 8, and 10, so one simplier option is to just get new fittings. Selection of the required fittings is a fairly simple task once you understand the jargon. But then you must determine the different types and sizes of beadlock O-ring fittings used in the X1/9 system, and where they are used. There is at least one (low pressure switch block) that must be cut and re-brazed with a new beadlock ferrule (the thing that gets crimped on the final hose end).

To make this easier for folks doing future X1/9 AC restorations, I have compiled the required fittings, hose sizes, and other useful details about the X1/9 AC system in a simple graphic attached here. I even listed the length of barrier hose and the sizes.

So, in the following I will post what I learned about each of the systems. I will start with the condenser, since that is the main upgrade aside from barrier type 134a hoses.

I will post these as installments since it's too much to post at one time.

Overview of AC Conversion and Upgrade for the X1/9

I pulled together the diagram below as a schematic of the X1/9 AC system, that otherwise does not exist anywhere, and as a summary of all the components. This is focused on upgrades to a modern 134a system, but the arrangement and fitting sizes are the same as stock.

And here is a list of the components, their sources, costs, and parts numbers.

1. Receiver-dryer
-Part: Jaguar XJ6 4.2 (78-81) - OE# CAC2338
-Source: Rock Auto 31.25

-The drier has the correct forward #6 male insert O-ring (same as condenser on that line) and rearward #6 female O-ring fitting ends

2. Expansion Valve
-Part: O-ring expansion valve
-Source: http://www.nostalgicairparts.com/air-conditioning/o-ring-expansion-valve-52.php
part 94-9873

3. O-Rings (AC type)
Source: Cold Hose, http://www.coldhose.com/
O-rings Pack Of 20 # 6 Hose ,1.99
O-rings Pack Of 20 # 8 Hose ,1.99
O-rings Pack Of 20 # 10 Hose ,1.99

4a. Fittings for new barrier hoses
Source: Cold Hose, http://www.coldhose.com/
2 0 B131FS # 6 45 Degree FOR O-ring Fitting $5.25

1 0 A133FS # 10 Straight FOR O-ring Fitting $5.75

1 0 B132FS # 8 45 Degree O-ring Fitting $5.50

1 1 A142 # 8 Straight MIOR O-ring Fitting $6.25

1 1 WS571 # 8 Weld On Beadlock Barb (outer) $2.99 (for low pressure switch block)

4b. Fittings with Service ports at compressor
Source: Nostalgic Air
1 A132-3 # 8 Straight Female O-ring Fitting with R-134a Port $9.49
1 A133-3 # 10 Straight Female O-ring Fitting with R-134a Port $9.99

4c. Fittings for short drop/right angle connection attaching 4b above to compressor
Source: Nostalgic Air
If the hi and lo ports on the compressor are same size, it is tube-O (OEM compressor)
then use 90° compressor adapters, with #8 & #10 connections

1 TO1606 Tube-O Fitting Discharge High Side Port R-134a $14.99
1 TO1605 Tube-O Fitting Suction Low Side Port R-134a $14.99

or

Source: Pure Choice Motorsports
Part: If the hi and lo ports on the compressor are 7/8-14 (#10) and 3/4-16 (#8) fittings respectively, it is standard O-ring (not tube-O) (new compressor)
then use

Source: Pure Choice Motorsports (http://www.purechoicemotorsports.co...ategory_id=98/home_id=-1/mode=prod/prd301.htm)
1 15160 Tight Fit 90° AC Elbows #8 $39.95
1 15170 Tight Fit 90° AC Elbows #10 sizes $39.95

5.134a Barrier Hose
Source: Cold Hose, http://www.coldhose.com/
10 feet BH6 # 6 (5/16") Barrier A/C Hose Per Foot $3.49
13 feet BH8 # 8 (13/32") Barrier A/C Hose Per Foot $3.75:
5 feet BH10 # 10 (1/2") Barrier A/C Hose Per Foot $3.99

6. Compressor
Part: equivalent 134a Sanden: SD5H14 or SD7H15
#8 discharge fitting 3/4"-16 threads
#10 suction fitting 7/8"-14 threads
Part: Sanden 4709 (SD7H15)
PN: 15-5001
Source: http://www.nostalgicairparts.com/air-conditioning/new-sanden-style-709-v-belt-double-groove-2.php $184.99

or

-Source: Summit VTA-04808-VUA $198.00

7. Condenser
Part: Nostalgic Air 11 X 19 Superflow (parallel flow) R-134a Condenser
11" tall x 22" wide (Core size: 10" tall x 20" wide x 7/8" thick) Part Number: 44-1119
Source: Nostalgic Air $84.99
http://www.nostalgicairparts.com/air-conditioning/11-x-19-superflow-r-134a-condenser-328.php

Top: #8 Male insert (3/4"-16)
Bottom: #6 Male insert (5/8"-18)

So these are the "ingredients." In the next installment I will start reviewing details of each of the components and any tricks that I discovered along the way. Stay tuned!

 

[bbrown]

Another "Best Of" writeup !!

Larry, A GREAT write-up on the AC system for our X1/9's.
Best I've seen. :clap: :nod:

 

[TonyK]

Very nice write up.

Just a mention.

Not all cars came with the frost preventor valve.

Nice that you have put the links to the parts. This is also a very hard part of restoration to get over.

TonyK.

Grimsby Ontario Canada.

 

[Felipe]

Larry

That was FANTASTIC!!! Great work, sourcing and lay out. As long as THIS forum exists I will always own at least one X.

 

[lookforjoe]

Awesome parts list!

I think I'll replace the condenser when I install the Howe Racing 3" core radiator I'm in the process of ordering

I'm just gonna make adaptor hoses to connect to the stock hoses, since I know those are in good shape.

 

[ryan]

This totally must go into the best of area. :shock2::worship::dance2::clap:

 

[LarryC]

Part 2 -Details

Looking at the schematic diagram, I will start at the top of the page and work my way down to discuss anything that I think is useful to include as a detail.

Let's get the hoses and fittings out of the way first.

Hoses and Fittings
Hoses and fittings are the next most important part of the upgrade process after the condenser (below) and are probably the most confusing part for us AC neophytes. AS Tony K says, these are the hardest parts to find. not because they are not available, but because they need to be sourced from different places to find all the types you will need. Hopefully my list will help.
Basically the X uses a pretty standard "beadlock O-ring" type fitting style of AC lines. Beadlock refers to the crimping of the hose on the fitting. The O-ring is the part that seals the fittings. There are three sizes that are used on the X: #6, #8, and #10. The trick is determining where these are used where and the type. By type I mean whether the fitting is a female, male or male insert O-ring fitting. That's right it uses three types of those types. See the diagram for an explanation of the differences and where they occur in the system. The #6 is the smallest diameter and lives between the condenser and dryer, and between the dryer and the evaporator. Then it is #10, the largest, from the evaporator to the compressor suction side, and then # 8 from the discharge side of the compressor back to the condenser. Along the way there is the expansion valve, the frost prevent valve, a couple of thermal switches, and a low pressure switch.
The only fitting that needs special work is the one from the low pressure switch block to the discharge side of the compressor and usually mounted in the front left corner of the engine compartment. On that one you have to cut off the old ferrule and have a new ferrule brazed on. Then it gets crimped to the new #8 hose that comes off the discharge port of the compressor. We will talk about the compressor end of that hose later. Because of the differences in AC systems on various models, it's best to measure your old hoses to get the right dimensions. So the dimensions I list in the diagram are just starting points for figuring what amount of barrier hoses you will need. Best to measure yours first. Once you get the new hoses cut to length and slip on the new fittings, then the fittings need to be crimped on those. I took my assemblies to a local hose/hydraulic shop and had them do that part. Then it's just a matter of snaking the hoses into their respective locations having already installed new 134a type O-rings. Use compressor oil to lubricate these so that they don't get mangled during installation. You need to keep the hose ends covered while getting the new hoses into their respective locations obviously to avoid plowing an open hose end through some of the tight places and picking up dirt and debris. On the long #8 hose that goes beneath alongside the water pipes, it's best to roll the hoses into the plastic clips after lubricating them with something. Note that this hose is the only one that uses a male insert O-ring fitting where it attaches to the hard line coming off the low pressure switch in the front corner of the engine compartment. All the other fittings on the hoses are male or (mostly) female O-ring type. See the diagram for an explanation of the differences and where they are used.

Here is what a completed set of 134a hoses looks like. Note the pesky low pressure switch block on the left.

Condenser
The condenser is the heart of the system really and should be selected with some thought. Bigger is better. But the front spoiler and short height in front of the radiator is definitely the main constraint. It should be 1.25 times the volume of the evaporator, which is the part that lives inside the AC-heater box. Fortunately while I was rebuilding the box I carefully measured it to establish its dimensions. The X1/9 evaporator turns out to be 128 cubic inches, so something like 160 cubic inches is desirable for the condenser minimally. But more is better. The Nostalgic Air 11x22 is 7/8 thick giving it a volume of 175 cubic inches. But it is a parallel flow type ("superflow") condenser with about 20 percent greater efficiency than the stock tube and fin condenser, or close to 200 -220 cubic inches equivalent of a tube and fin style (the original condenser design) in theory. Technology has advanced, so the new parallel flow design is a good addition.

The new condenser will mount in the stock location by fabricating a couple of brackets from aluminum stock.

The assembly mounts up nicely and solidly in front of the radiator like this.

Notice that in this picture I have yet to remove the old hoses. A #8 and #6 FOR 45 degree fitting is used to connect to the two fittings on the condenser which are #8 (top) and #6 MIORs.

Receiver/Dryer
This has been discussed before and is a Jaguar XJ6 4.2 (78-81) AC dryer. It has the correct offset between the inlet and outlet which helps a lot in lining things up in the narrow cover. I made an aluminum strap that wraps around the can and allows this to be mounted just like the original. The only trick is using 45 degree fittings on both sides. But 45 degrees is too much and puts the hoses below where they need to be. So I simply re-bent the angle to something more like 20 to 30 degrees and it fits perfectly.

High Pressure and Condenser switches
The two switches that live on the inlet fitting at the dryer can be reused and mount perfectly on the new fitting. The use of 45 degree fittings is another benefit here since there is limited shank room on straight fittings for the two switches. 45 degree fittings use a longer shank which works out fine once straightened a bit. I reused the original mastic tape and clips that hold the switches in place. TonyK explained the "high pressure switch" to us in his original AC discussion a while back. This is actually a temperature switch that uses temperature as a proxy for pressure. So there is no actual pressure switch.
One word of caution: Before you disconnect these from the original lines, be sure to note which wire goes where! The factory wiring diagrams are no help at all, and the colors changed over the years anyway, so getting the right switch connected to the right wires is a 50-50 thing unless you keep track from the start.

How the switches are mounted on the inlet fitting at the dryer.

In part 3 I will cover the rest of the system. Then I will go over anything else that relates to getting the system up and running.

 

[lookforjoe]

Did you buy the beadlock crimp tool, or rent one? I ordered the fittings to make hoses for the 11x19 condenser (thanks again for compiling the list!)- and then realized I need a crimp tool :sigh:

 

[Yves]

Wow

Larry,
I lift my hat ... great writeup:clap:

 

[LarryC]

Hussein, I just took the assembled hoses to a hydraulic shop

and had them crimp them. I figured that I had enough money invested already in other stuff and was not needing another tool for a one-off use!

 

[lookforjoe]

and had them crimp them. I figured that I had enough money invested already in other stuff and was not needing another tool for a one-off use!

Right - thank you Larry, I'll look around for a local shop.

 

[Black-Tooth]

Kudos to my BEST FRIEND Larry!

What a great write up and more Kudos for going all "stock"...

As for me, if I ever pull my non A/C car down again... I'll be opting for a Vintage Air Hot Rod kit. It will go in FIRST before anything else!

 

[LarryC]

Part 5

Here is the third installment of my AC restoration and upgrade discussion. There will be a fourth once I have tested the system in a variety of settings.

Expansion valve
No tricks here, the new expansion valve pretty much fits right up and the frost prevention switch clips on with no problem. Just coil the sensor tube before installation, comparing it with the old one and you should have no problem getting this in place.

Low Pressure line to Front Prevent valve
Nothing to note here except that the low-pressure line changed over the years. When making up this line you would be best to just see how yours was done. The frost prevent valve is fairly durable and can be cleaned up and reused in most cases. Be sure to reconnect the blue-white wire to the valve.

Here you can see where the #8 ferrule was brazed onto the low pressure switch block, a new hose crimped in place, and the block mounted and connected to the hard line disappearing towards the bottom of the front of the engine compartment. From there the line runs alongside the speedometer cable before looping over the steering rack tunnel to the passenger side, and then forward to the condenser.

The frost prevent valve gets cleaned up if it is working and remounted. Don't forget to reattach the small blue-white wire.

Compressor
The X1/9 used a Sanden 4508 (SD5H14 in 134a equivalent) type compressor. This is a five-cylinder compressor. I bumped up to the 4709 (SDH15), which is a seven-cylinder design and said to be a bit smoother in operation as well as slightly higher capacity. They are all the same dimensionally. The original compressor used fittings on the suction and discharge side that are about an inch in diameter and the same size on both. Those are what are known as "tube-O" fittings.

Here is the SD7H15 mounted up to the original compressor brackets and ready to install.

Here is the compressor block mounting brackets cleaned up and mounted to the block.

All the current crop of compressors use a standard O-ring #10 on the suction side and #8 on the discharge side. The X1/9 needs a right angle out of both port really quick, and the options are limited. Most systems use right angle beadlock fittings, but it seemed to me that something more like something more like the original tube-O arrangement would help with clearances. So I search around and found these hiding in a small hot rod company called Pure Choice Motor Sports. Work just fine. You will need a #8 and a #10. Expensive but work well. Look cool too.

For service ports you can then hook up these connectors with standard straight beadlock O-ring fittings with service ports as listed up there in the parts. The trick is getting them lined up in such a way that the service gauge attachments have the room needed so that they will fit in the tight space.

Here is the compressor installed and fittings attached. I used a 31-inch belt on the compressor pushing the compressor as far loose as it would go by removing the clamping through bolt, and walking the belt onto the crank pulley using the passenger tire jacked up as a crank to spin the engine forward in small bumps. The small original heat shield that protects the hoses at the bottom edge of the access panel opening no longer fitted due to the length of the fittings with the service ports. So I installed ThermoTek sleeves on both fittings where they pass behind the exhaust downpipe.

Any heat added to the compressor gets added to the heat that the condenser has to shed. So as additional protection for the compressor head where it is closest to the exhaust, I fabricated the aluminum heat shield that effectively wraps around the exhaust components and provides considerable protection for the compressor, the AC hoses, and the alternator. Sort of an upgrade over the small heat shield that the factory had on the back of the compressors. The shield was fabbed in cardboard initially to get all the right angles, then bent, drilled, and installed with a few tweaks. Things use to get melted back there, but now appear quite happy with life in that location. So it must be working very well. Also, oddly, I notice the carb cooling fan doesn't come on as often. I am not certain hot that would work, but there it is.

The completed heat shield. The hole is used to mount it to the bracket shown below.

Bracket holding the heat shield is attached to the center stud of the exhaust manifold originally used to support a heat shield that covered the exhaust manifold. This appears to be a sturdy mounting solution and holds the new heat shield firmly away from any nearby surfaces.

 

[autocomman]

Good write up, Ive half started some research on adding A/C to an X with the early dash that only Dealer A/C was offered on. Its gonna take some fabrication, ive been looking at some universal A/C/ heat options. Prolly a vintage air box with stock compressor brackets and all custom hoses and controls. Dunno yet. Ive gotten bogged with with British car projects latley and I havent been able to even tear down Moms X yet :sigh:

 

[lookforjoe]

Nice Work!

I think I should copy your heat shield idea for my Allison header - I have nothing isolating my ancillaries.

 

[LarryC]

I don't think this is part 4 yet, but..

So today was the first real test of the revamped AC system with a "daily drive" type situation. I had completed some serious tweaks to the belts and other things, like getting the fast idle system working (don't ask….it's a 79 carb set-up), over the weekend, but did no test driving to speak of. And the Supreme Wife decided we were not only going to drive it to work, but we needed to drive to and from via I-40 and to make a stop on the way home after multiple traffic lights….in 99 heat, at least by the thermometers distributed around our property. The hottest day since the end of June actually.
So I am hoping that the whole thing doesn't explode given that this is my first AC rebuild experience and the first real drive. Also, I have only charged the system about 3/4 with about 24 oz of 134a and should probably have about 30 oz in there. But I am happy to report that not only were we cool, but it all worked well. The condenser fan came on and turned off periodically, sometimes while the radiator fan was running, and the voltmeter never moved below 12 volts even with the blower at maximum. I'd say that the rebuild is a success.
More information as it occurs to me.

 

[LarryC]

O.K. still not Part 4 but....

Just to emphasize that this otherwise experimental rebuild appears to be a success: Today- 65 mph at 5000 feet altitude for 20 miles with the AC at full blast while climbing 1000 feet in the mid-90sF. Shut down with carb fan coming on and turning off twice while sitting. Then a repeat performance (fortunately down 1000 feet). Don't ask why. It's a conspiracy to test my nerves. But no issues. :nuts:

 

[Ellychiprout]

Congratulations, well deserved success!

 

[LarryC]

Part 4 - Analysis of results

So I will go ahead and wrap this up for now. Basically, after one hell of a week of unintended full tests in all types of temperatures, operation times, and speeds, with stops and restarts, I think I can say that I am pleasantly surprised at the performance.

Radiator Cooling: As we all know the X1/9 cooling system can be overstressed in hotter climates, so I was frankly concerned that the AC would only exacerbate the potential for cooling difficulties. In hot weather the coolant temperature often gets to the point where the fan comes on and it always seems like it could get worse real quick. Never has, but there was always that nervousness when it was up there with simple city driving. Conclusion: Apparently not. The coolant temperatures rise more quickly to the 190-200 mark, but the combination of radiator fan and condenser fan appear to handle the heat excellently. The temperature needle rises to 190-200, the radiator fan kicks in and the temperature holds steadily. This is in both city and freeway driving. The fans both come and go, so they are doing their job, are able to keep up nicely with the task, and temperatures are being maintained. I do run the advance at stock specs. This could be a help during summer months since advancing the timing will tend to generate a bit more heat. Could be a secret of cool summertime running along with the increased idle speed that may circulate coolant better. Just a speculation.

Operational caveats: From my previous experience I recalled that the AC compressor robbed a lot of power. That is still the case. You will not be doing any spirited driving with the AC on. Not that you can't, but it's just that AC is kind of a negative performance upgrade so to speak. So you feel an overall lack of torque and aren't particularly encouraged to zip around. For instances where some extra power is required, like accelerating onto a freeway ramp, I simply turn off the AC and put the controls on heat (ventilation) with the temperature control lever turned off. This lets the fan continue to blow cold through the evaporator for several minutes until you can turn the AC back on. Once up to speed you can reengaged the AC and drive in comfort. I always turn the AC off before shut down.
Also, I usually turn the AC on in "max AC" (recirculated air) and switch to normal AC (exterior air) after things get chilled. I notice no apparent difference in the AC temperature output in normal AC even on hot days.

Idle speed: On a carbed X, the idle speed is bumped up a couple of hundred rpms during operation and makes shifts a little awkward feeling. But since everything is much slower anyway, you just shift a bit more stately. I had to rebuild both the idle speed vacuum capsule and the vacuum diverter valve (it can be done - another long story for another time) and they work. But the diverter valve needs a little more work since it takes a few minutes for it to re-seat, leaving the idle speed up even after the AC is off. It eventually settles down, but I would like it to seat immediately.
I am also impressed with the amount of air that comes out of the two side vents. On most cars those side vents are of little use. Not on the X. They will frost your left hand on the steering wheel.

Alternator: The GM alternator I am running, and have run for 15 years now, appears unfazed. With the idle speed up during operation, it is completely happy and maintains a near-horizontal voltmeter with the radiator fan, condenser fan, and blower fan running (at one click below max). Once the fans turn off the needle jumps to the 13.5-volt position. This week also included use of headlights (with relays and BWM) and there was no noticeable difference.
The air coming out of the vents is not frigid, but decidedly cold. Which is probably to be expected during 90-degree weather. But it is enough to make the small cabin of the X plenty cool and fairly quickly. As I stated earlier, I think I am not quite fully charged yet, so if that is the case, it's doing very well. I am running straight Dupont 134a.

Overall: Frankly, I didn't expect much given all the potential cooling system weaknesses. Papa Tony has often noted that not too many people in the warmer climates seem to have working AC, and I agreed because it seemed like the X is just not up to modern expectations due to the apparently easily overstressed cooling and lack of power. But that appears not to be the case. The whole system is completely capable and works as well as any vehicle. I can turn the AC on and, other than the caveats above, forget about it. The fans turn on and off, the inside gets cool, and I can go about my business.

So anyone with similar doubts can forget them. It could be that you would need to completely rebuild the system with new components as I have, or it could be that rebuilding and cleaning the AC-Heater box is important. My AC system is essentially all new now. But whatever the reason, it works well. Now all that remains is to see how it all holds up with time and use. I started out not knowing anything about AC really, and it took me 11 months of off-and-on work and research, mostly figuring out the hoses and fittings along with the small matter of the AC-Heater box and blower fan rebuild, but I finally got there. If I can do it, anybody can.

 

[budgetzagato]

Cool...

Get it? Cool?

This is helpful and encouraging, as I've decided to resurrect the A/C in my Scorpion. Your posts will help a lot.