'70 Nova LSX swap LY6/TH400

[CarterKraft]

Originally Posted by TheBandit

Great idea with the sockets, although I am planning to go to full-panel LED setup and I will do a dedicated ground for that.

The fan fuse was a lot of luck on my side to be honest. Luckily I caught the gauge spiking before it got too hot. And I wasn't very far from home or an auto store. I should have had a few spare fuses with me and I should have remembered to swap out the 30a for a 40a like I originally planned. Live and learn!

Yeah funny story about the LED panels.... We had those on the list too, they never got made because the sockets and the red LED 1157 bulbs worked so well.

I am pretty sure I already had a 40 amp fuse in the truck for the fan but I know I don't have a spare...

[CarterKraft]

Originally Posted by TheBandit

Many years ago I picked up compressor fittings from Docs Blocks just before they went out of business. I got both straight and angle/tube adapters and ended up using a combination: straight on the suction side and right angle on the high pressure outlet. Unfortunately the right angle adapter pointed directly at the radiator hose.

The tubing on this outlet adapter is #8 which has a 1/2" outside diameter (number/dash sizes correspond to sixteenths i.e. #8 is 8/16" or 1/2"). I didn't have a 1/2" tubing bender, but I found a cheap hand bender at the local parts store to get the job done.

Now the outlet points in a favorable direction and I will be able to route the high pressure hose with a service port fitting toward the front of the car.

I am hesitant to bring this up for fear of being a party pooper BUT... The low mount A/C has really caused us some grief. The line routing sucket but we made it work. The clearance sucked but we made it work. To prevent future problems we started with a new compressor, that promptly burned the rubber drive off the compressor clutch after a week and splattered molten rubber all over the underside of the hood...

If I had to do it again I would mount it higher up somehow looks be damned.

[TheBandit]

Can you elaborate on what happened? Did the compressor seize up? Was it getting slugged with liquid refrigerant? Any idea of you were over charged? What kind of pressures were you seeing when you charged it? Bubbles or completely clear sight glass? What kind of oil did you use? How is the system working now?

[CarterKraft]

Originally Posted by TheBandit

Can you elaborate on what happened? Did the compressor seize up? Was it getting slugged with liquid refrigerant? Any idea of you were over charged? What kind of pressures were you seeing when you charged it? Bubbles or completely clear sight glass? What kind of oil did you use? How is the system working now?

Brand new Vintage air MArkIV system with new Oreilly(unsure of brand) fixed displacement compressor, looks the same as yours. Vacuumed down for 2 hours and charged per VA capacity. System cooled well and pressures were good albeit a little high due to low CFM cooling fan when parked. PAG 46 I think???

A couple of weeks later it either locked up or??? and burned the rubber drive coupling of the compressor clutch out which slung the molten rubber all over the engine bay.
Autopsy showed no immediate cause of failure. Repeat the same process with new compressor (same brand) and all has been well for a year or so.

In our situation the frame rail clearance sucked and having to do it again I think I could have put it higher up on the engine and moved the engine rearward like I wanted, just would have been easier all around save for looks.

[TheBandit]

Well that sucks! I guess I'd chalk that up to $#!+ happens if it's running okay now. The sacrifices we make for a "clean" install!

[TheBandit]

This weekend I borrowed a Mastercool 71550 AC hose crimper and made all the hoses for the system. Here's what a typical fitting looks like coming out of the tool:



This tool is very simple to operate. It comes with dies for sizes 6,8,10, and 12. I marked my fittings and hose on the car to make sure they had the right orientation, then held them in the tool while tightening the large acme screw at the top. This brings the dies together which put indentations around the fitting to clamp the hose. There is a mark on the tool which tells you how far to crimp.

The first hose I made goes from the drier and runs under the fender around to the TXV.



I put a high side service port in the discharge line just after the compressor. I've got a lot of hoses (2x transmission, 2x AC, coolant, coolant overflow) and the starter cable routing through this area and it's starting to get crowded. I had to disconnect the transmission lines while I was doing this so I could rearrange things. If you look on the left of this photo near the heater bypass loop you can see the larger suction line which connects to the compressor with a 45 degree fitting.



The discharge hose goes from the compressor and loops up to the top of the condenser as shown below.



I used a 90 degree fitting at the bottom of the condenser for the liquid line going back to the drier. I had to sneak it between the transmission cooler inlet and return lines.



I saved the expensive shepard's hook fitting for last.







Here is how the engine bay is shaping up now that the AC is fully plumbed.

[mdslngr77]

Have you seen/used EZ Clip fittings? I work for for a transport refrigeration and offroad AC company and we switched from bubble crimp to this and it was the best thing we've ever done. Much simpler install and hose durability seems to generally be better.

[TheBandit]

I did come across those. They are neat because you can do them in place. But they seemed to be much more expensive with fewer styles and sizes available.

[CarterKraft]

It looks bitchin for sure.

[mdslngr77]

They are a lot more convenient. Variety of fittings is getting better as popularity rises with them. I like the fact that they are reusable too, if you have a rubber line crack, you can cut the clamps install new orings and slide a new hose up on the fitting - also nice if the fitting seizes to a component such as evap or condenser you can slide new hose on without removing fitting from component.

http://www.partdeal.com/hvac/fitting...anufacturer=59

not who I source from but they list a good assortment

[TheBandit]

Those are great mdslngr. A good option to be sure!

Here is a hyperlapse video doing a couple fittings with the Mastercool 71550 AC hose end crimper. I had a little trouble at the start of the video with the pin and had to tap it in with a hammer.



This tool runs around $140. The local Napa charges $4 per crimp and this system has 8 fittings = $32. I probably would not buy this tool unless I was planning to do at least three or more systems, but I will say having it on hand was very convenient and allowed me to mark and crimp as I went along. This was loaned to me by an awesome local hotrodder who does refrigeration for a living. I'll be sure to pay it forward when someone else needs my help or tools!

[mdslngr77]

We used the hydraulic version on our service trucks before switching to EZ clip, made it nice to be able to crimp directly on the unit we were working on, so we could route our hoses before installing the fittings - handy when your running 30-40 foot of hose around a 250ton crane

[TheBandit]

Went out cruising last night with a local hotrodder and his passenger took some really cool rolling video!

[entropy]

Good looking ride there.
You should see if Leno would feature it

E

[TheBandit]

Thanks E! I don't think it's quite Leno level material but it makes me happy!

[entropy]

Originally Posted by TheBandit

Thanks E! I don't think it's quite Leno level material but it makes me happy!

...And happy is what this is all about!
Maybe one day I'll get one of my various POS at-least to the point where I can sit in it and go:
Verrrrroom! Verrrrroom!

E

[TheBandit]

I decided to get back to work on the AC project.

Here is my to do list:
- Adjust POA valve
- Flush evaporator and POA valve
- Install o-rings throughout
- Install hi pressure switch
- Add PAG oil
- Wire compressor and fan relay
- Install compressor belt
- Evacuate and charge

Starting with the POA valve, I recently picked up the 1970 chassis service manual which has all kinds of great info on how the AC system works as well as diagnostics and repair. Per the service manual, the valve setpoint from the factory was 29.5psig at sea level and that appears to be where mine was adjusted. To get roughly the same evaporator temperature from R134a as I would have had with R12, I would need to adjust the POA down to about 27psig, however after a little discussion and reading up on the auto ac forum I've decided to target a lower pressure of 26psig. This will give a freon temperature of about -1C or 30F which is technically below the freezing point of water, but with warmer air flowing over the evaporator it's still very unlikely to ice up and should give better cooling performance.

Here is a video explaining the POA adjustment. I used a 3/8" socket to loosen the lock nut and a 7/32" socket to adjust the setscrew.



It was really hard to see the gauge or line up the camera phone while taking video, so I went back and snapped a photo to show it indeed was set at 26psi.



Satisfied with the POA adjustment, I took it off the system and got setup to flush the evaporator. Flushing removes any residuals of the old lubricant and R12 residuals that may not play well with the new R134a, as well as cleans out any debris that may have accumulated while the system has been unsealed for the last twenty years. I used an aerosol flush called A/C Pro "Power Clean and Flush". Below is a photo showing how I set it up. The flush is fed into the outlet of the evaporator and I used clear poly tubing at the evaporator inlet to a plastic container under the car. That allowed me to monitor the color/cleanliness of fluid coming out. Once I ran all the flush through, I blew it out with air.



Below is a video showing some of the process. When I went to air blow the system, some of the flush was forced out of the small oil bypass line so I added another tube to route that down to my collection container. The function of the oil bypass line is to make sure oil in the system is always allowed to circulate back to the compressor even if the POA valve is mostly closed.



Here is my collection container showing the amount of flush that went through the system and the resulting color. The amber color of the fluid is mostly from the first few seconds of flushing when the flush came out pretty dark.





Not photographed, I also flushed the POA valve on the bench into a bucket. This concludes my presentation for today.

[entropy]

Cool to see someone take it on; even though I understand the theory on AC, it is still magic.

[TheBandit]

Thanks E. I'm with you - it is pure magic. I have been thinking about making a video explaining how the whole system works, including some analogies to explain the basics of refrigeration theory and a practical explanation of the components and workings. Why I feel compelled to make a video is beyond me though - I think there are already quite a number of them out there.

[entropy]

The quote I got for repairing the system on my Ranger was well over $1000 for just the Parts & Materials; the $800-thingamabobber failed and would require replacing a bunch of parts, evidently cleaning not replacing voids the warranty on the new thingamabobber.
The windows still roll down & up perfectly...

E
I'd watch a vid