Making some progress now!
Well, I finally got back to the AC retrofit part of my build. I must admit that fitting an aftermarket AC system to the X1/9 has been a headscratcher, to say the least.:hmm: Refurbishing a stock AC system as LarryC showed is probably the easier way to go. I just could not source all of the stock parts and bringing home another X donor car if I could find one to strip would push my wife over the edge.
There is quite a bit earlier in this thread showing how I was going to fit this to a stock X1/9 engine with a Delco alternator and all of the brackets that I fabricated for that. Then I wandered over to the dark side with my K20 swap and that is what has been occupying the past year of my free time. Anyway, back to the AC.
Finding the best position for the evaporator unit in the space of the original heater box took a while, then figuring out how to mount it securely to the body was the next challenge. The Hurricane unit was designed to mount to the firewall of a front engine car so it has three mounting nuts in the case on the side of the outlet/inlet tubes. I attached some brackets I made to these points and then also bolted it to both sides of the tunnel.
To hold it down on the console side, I ended up disassembling the whole unit to cut a hole and epoxy a flanged nut at the base of the evaporator.
I chose a spot that lined up with the threaded hole on the tunnel where the fiber optic bulb housing was attached. An angle bracket held it down there. I put a strip of rubber down on the tunnel to eliminate any creaking from vibration.
There are many things that ran through my mind as I was working on this project. I kept thinking about how to incorporate the controls for the unit. There is also the issue of the hole in the cowl below the windshield that normally has the fresh air flap at the top of the heater box. Do I just block off the hole or try to still allow fresh air? The Hurricane unit is strictly a recirculation type unit.
There are a few different control options available for the Hurricane. Unlike the vacuum powered stock X AC system, the Hurricane is all electronic servos. There are rotary controls as well as two different sized slider control modules. When I ordered the system, I picked the large horizontal one as it was a similar size to the stock control area and I thought I could make it work in the stock location. It was too long to fit without interfering with the clock and too short to take up the whole width. So I put it aside for a while and mulled it over while I worked on the evaporator stuff.
I happened to pick up a used stock AC control unit with the push buttons from Greg Smith and started taking it apart.
In comparing it to the original heater slider controls that came on my car, I noted that the base frame that holds the fan speed switch and the sliders is the same for both AC and non-AC. Fiat just left off the two upper sliders and added the button unit. Also the fan switch has three speeds with the AC version, but only two with the non-AC. The Hurricane control also has a three speed fan switch. The only difference is that it also provides power to the system when the fan is switched on so that the AC compressor does not run when the fan is off.
I tried the Fiat switch with the Hurricane fan and it worked just fine. Ok, I thought, maybe I can modify the stock AC controls to run the Hurricane. There are two long sliders with the control unit I bought. One controls the temperature by operating a servo on the hot water intake and one controls the servo that moves the flap between vent and defrost. The non-AC slider faceplate has the middle slider/slot to control the temperature and the top slider/slot to control vent and defrost. Hmm, this is promising.
I took apart the Hurricane slider control unit and the two sliders are just long rheostats that were a bit shorter than the slots on the non-AC faceplate, but not too much different.
I figured out which way to mount them so that they would control the temperature and defrost/vent correctly and then with some spacers and epoxy, constructed my custom control unit using the stock AC base and fan switch with the non-AC faceplate.
The bottom slider on the AC base normally controls the temperature valve in the stock system, but it controls the fresh air flap in the non-AC car. The cable connection to the slider control is identical. I cut off the flap part of the original heater box, refurbished it and then mounted it in its stock location. I shorted the length of the mounting studs from the cowl and reversed the mounting bracket for the cable coming off of the flap housing to allow more clearance above the Hurricane unit. So now, I will have the ability to open the fresh air flap as usual if I want, or close it for AC or heat. Plus, the dash will look pretty much stock.
I modified a couple of broken stock slider knobs that I had to hold the metal clips from the Hurricane slider control knobs. I didn’t slide the new knobs I have onto the stock lower slider or the fan switch yet as they are such a pain to get off intact, but they should all line up nicely. I was kind of proud of how it all worked out.:woot:
There is a lighted push button on/off switch that was on the right side of the Hurricane control unit. It is just about the same width as the rocker switches in the console, so my plan is to mount that in one of the rocker switch openings, using a blank plate to fill in the space above and below the switch.
The next thing I accomplished was getting the connections for the heater worked out. Unlike the stock X1/9 heater valve, the Hurricane valve unit has two lines in and two out, plus the servo that controls the valve.
I bent the stock metal heater coolant supply tubes to move them more into the center of the tunnel. Also, the tube closest to the frunk sticks up higher than the rear one. I cut that one down so it was the same height as the rear one.
I used short sections of heater hose to connect those two tubes to the appropriate valve tubes. I then needed two 90 degree bends to connect the valve to the Hurricane heater tubes. I went down to the local O’Reilly’s and they let me look at what they had hanging on the wall in back. I found the perfect piece of tubing, Gates #18799. It had two 90’s in it about the right length.
I cut it between the 90’s and it was a pretty nice fit. If I were to do it again, I would have cut it closer to the bend with the short tail so that the top hose was a bit longer, but it all seemed to go together pretty nicely. Of course, once I do the final install, there will be hose clamps.
Also, part of this was plumbing in the drain hose from the Hurricane to the stock opening in the floor pan. I found a nice 90 degree PVC elbow that made a nice connection from the Hurricane to the drain tube. I did have to create an opening in the side of the tunnel for the tube to pass through. Bending the heater coolant supply tubes toward the driver side allows room between the tube and the side of the tunnel for the drain tube to fit.
That’s where I am at for now. The pictures show the unit without the top airflow manifold in place. I couldn’t get it into position with it all together with the fresh air flap housing in place. I was able to attach it afterwards, but left it off to be able to see better to fit the heater connections. The next part will be to fabricate custom connections between the manifold openings and the defrost/vents openings in the dash. Then the AC hoses to the dryer and onto the condenser. Lastly, I have to figure out how to mount the compressor to the K20 engine. The stock location for the AC compressor is not available because of the cross member at the base of the firewall, plus the subframe mounts to two of the mounting holes for the compressor. I have seen pictures of a couple of K20’s that Matt did with the compressor mounted up where the power steering pump was, but I will have to fabricate a custom mounting bracket for that. Piece of cake…..not!