Miata AC for the Molvo. Any idea what I am starting with?

High on the list is to have AC in the Molvo next summer.

To that end, I have dug out the AC components that I bought from a member here many moons ago.

While most of the bits will not be used, it would be useful if I knew what year the parts are from. I am pretty sure that this is a 134 system based on the ports.

The main component of concern is the condenser, since I did already make mounting provisions way back when. It would be useful  for documentation reasons to know what year Miata it came from. The seller indicated 94, but I have doubts.

I can not reconcile the broken line to fit in this location. (Above pic)

I think I have the gist of how the system is going to go together. Not that I will use any of the fluid lines in the images, just trying to see if I have the flow path correct.

The other thing I am struggling with is parts specification. I have no idea what size nomenclature is used for AC fittings and I will need that knowledge if I want to communicate with a vendor. This is complicated by the fact that the compressor is a Ford Mustang unit that may or may not be metric. 

I will not be using any of the hardware in the pics except for the compressor, the condenser and the evaporator ( not shown). What I want to confirm is the year of the system for future maintenance, and some idea of how to spec the fittings to that I can make hoses.

On a more controversial note, I plan to run the system on R12-a unless I can be educated on why not to. I have used it for top-ups on 134 systems and it works very well.

Some of those fittings are not found in nature, and can only be found by cutting them off the ends of Mazda hoses. That was a hassle when doing the V8 conversions.

I'm not good with AC so I can't identify that by eyeballing, but from what I remember of line routing I think 1994 is plausible. I'm pretty sure they were fairly similar from 1994-00. I do have a lot of 1994 AC parts I can check against if you want, I have a system set aside for a future install.

In reply to Keith Tanner :

Interesting. There are only two fitting sizes that I can see, and the most critical are the ones at the firewall that connect to the Miata evaporator. The rest of the system could go to aftermarket parts, but I do not want to mess with the factory fit of the evaporator.

So, off I go to see how one deals with making hybrid hoses from existing bits. I do own a crimper, so that might be a help.

Wondering when stuff will get easy with this project?

Can I tag along on this journey?  I'm about to do similar with an rx8 and a gm v6.

Can you run a brand new compressor without it connected?  Will it burn up?

If this is not a welcome tangent, just let me know and I'll start my own thread. 

Don't compressors only spin when the clutch is engaged? Seems easy enough to avoid.

I think the hassles we had were on the high pressure line - I can check. But you'll know when you get there :) We had them crimped together at a local hydraulic shop.

Confirmed, the custom fittings were so we could build lines from scratch. If you have a set of donor lines, you have the fittings you need. This is the sort of problem you come across when trying to productionize and be able to ship parts out, not a problem when you're building 1 of 1 in your home garage.

My needs are to understand what the numbers in the above chart mean. The only number that I can actually crossmeasure is the thread pitch. So for example, on a fitting where do I measure whatever a #8 might be. Where do I measure the M20? ect. Trying to cross reference this to what I have now.

Subbed to learn for my own miata hybrid. 

Dusterbd13-michael said:

Subbed to learn for my own miata hybrid. 

Dont know enought about your build to speak to the details, but what I am learning is that if you did not stretch your wheelbase 7" like I did, this is kinda not a huge issue. I am going to assume your car had a 134 system to start with IF it had AC from the factory and that you still have the factory system?

I think that the part that makes this fun is the circled unions.  In my case, this needs to transition between metric fittings on all of the Miata components, and non-metric at the compressor. Your situation might be different if your compressor is metric.

The transition from metric to non-metric itself is not a huge deal simce the hose size seems common to both, No 6, No7, No8 designates the hose size for the high and low pressure hoses. 

Where this might get fun is that No7 hose and fittings are not really a thing. Or at least tricky to find.

Note in the chart below that there is no corresponding male insert  fitting for the No 7 fitting circled.

In reply to Dusterbd13-michael :

We might have some leftover parts on the shelf from LS NC builds - lots of things in common with an LFX RX8. Ping me when you get there. 

In reply to NOHOME :

I would walk into a hydraulic shop and say "I need this". They do stuff like that constantly. 

So, what i need to do is use the stock nb evap core under dash, and the condenser amd drier in front of the radiator. All the hoses will be custom. 

We have a napa that does hoses and crimping for ac, but not fittings. 

In reply to Dusterbd13-michael :

Are you not able to use the Miata aluminum hardlines that came with the car? ( If you still have them).

If you can, then you only need to make the rubber flex lines that connect to the aluminum lines and to the compressor. 

In my case, I have the Miata evaporator under the dash, the Miata condenser and dryer  in front of the rad and the Ford mustang compressor on the upper LH side of the engine.  I just need to connect the bits with  A/C lines and fittings. The thread pich for the Miata fittings is 1.5mm Not sure about the non metric but the chart I posted is full scale and I can hold it up to a sample ane be pretty confident that it is going to fit,