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Slight redesign of A/C system

Burning oil

Burning oil

LeroyDiesel.com
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Couple things, Im installing a bigger condenser and installing orifice tube close to evap.

I found this http://www.autoacsystems.com/fasttrack/filters.html (pic at very bottom of page) it would kill two birds. With the new condenser I lost the spot to install a orifice tube, But that was part of the plan anyway. I want the orifice tube as close to the evap as possible (absorbs less heat than the stock set up).
The liquid line filter with orifice tube (in link) would be perfect for me, but I can't find this unit anywhere. Anyone have a link or lead on one? or something like it?

Thanks.
 
The orifice tube can go in the inlet of the evaporator. GM put it there on the R-12 systems, but moved it for some reason for the R-134 systems. I'm guessing this is a single air unit since you say changing the condenser took away the orifice spot. For dual systems the orifice went back behind the Y where the liquid line split off to the rear. Also keep in mind you will have to add a good bit more charge for the larger condenser as well as for the different placement of the orifice tube.
 
Yep single air on the CCLB. I wonder what size the orifice is on that one in the link? or what size would work? Seems like it might be easy to make the filter/orifice combo, then I could machine it for the correct size fittings too.
 
Many are now switching to the .062 orifice, but I like the stock white .072 myself. If your enlarging the condenser as much as you are, you may want to look into adding in an expansion valve to it. Your already going to be using custom lines, so it wouldn't be that much harder to add one in. Personally I would check your evap and see if it has the dimples inside the inlet line to hold an orifice tube in it. If it does, use an orifiec tube from a 88-93 truck and install it at the evap inlet instead of in the liquid line.
 
THEFERMANATOR said:
Many are now switching to the .062 orifice, but I like the stock white .072 myself. If your enlarging the condenser as much as you are, you may want to look into adding in an expansion valve to it. Your already going to be using custom lines, so it wouldn't be that much harder to add one in. Personally I would check your evap and see if it has the dimples inside the inlet line to hold an orifice tube in it. If it does, use an orifiec tube from a 88-93 truck and install it at the evap inlet instead of in the liquid line.
Click to expand...

Ferm that was a great idea! I just looked and evap does have dimples, but what do you think about the pics below. Question is do you think the orifice would be to far out? It looks like it could interfere with the line that would mate to evap?

DSCF1632.jpg
 
The orifice will seat against teh dimples at the portion where the white and black section is, not the end of the orifice tube liek you have shown. So it will go in another inch when fully inserted. Also I'm pretty sure you will want to run the all white orifice instead of the white black one when installing it at teh evap. Not sure what the exact difference is, but an orifice is only $2 or so and there was a bulletin about doing this awhile back I had found.
 
Great info! It looks like to get the orifice in all the way like you said I'll have to oil it up and make sure it go's in pefectly between the 4 dimples. I hope it will go. And I got a 1986 style orifice coming, would that be the all white one?
 
It appears to be from what I can find. You have to oil the O-rings pretty good to get it in all the way, and it takes a good bit of pushing to get it in there.
 
OK looked at the 1986 style evap today. Its the same as the one I have as far as the orifice tube go's. So it looks like it will work, but Im going to have to really push that thing in there.
So that solves that problem. Now to find a filter that will use #8 oring.

Thanks Ferm that saved alot of time and will make for a much better/cleaner/less prone to leak install.
 
THEFERMANATOR said:
The orifice tube can go in the inlet of the evaporator. GM put it there on the R-12 systems, but moved it for some reason for the R-134 systems. I'm guessing this is a single air unit since you say changing the condenser took away the orifice spot. For dual systems the orifice went back behind the Y where the liquid line split off to the rear. Also keep in mind you will have to add a good bit more charge for the larger condenser as well as for the different placement of the orifice tube.
Click to expand...

GM moved it to take the "hissing" noise out of the cab. Higher R134A head pressure makes more noise. Wives complain about the noise and GM recently had to add a "muffler" to Tahoe AC systems orface tubes over the noise. (The big white Styrofoam thing that is part of the late model orface tubes.)

An expansion valve would be a better choice all the way around for this system and easier to get the charge correct via the sight glass in the filter dryer. It would also cool better under all conditions from idle to freeway speed.

Again the sign the charge is too low is compressor oiling failure in a orface tube system. Will have to charge it on a standard o-tube before going with a VOV orface (variable) tube.
 
Burning oil said:
Couple things, Im installing a bigger condenser and installing orifice tube close to evap.

I found this http://www.autoacsystems.com/fasttrack/filters.html (pic at very bottom of page) it would kill two birds. With the new condenser I lost the spot to install a orifice tube, But that was part of the plan anyway. I want the orifice tube as close to the evap as possible (absorbs less heat than the stock set up).
The liquid line filter with orifice tube (in link) would be perfect for me, but I can't find this unit anywhere. Anyone have a link or lead on one? or something like it?

Thanks.
Click to expand...

Sure a filter is a good idea. In this case they are preventing the small screen on the orface tube from plugging. Risk of leaks, being missed with a compressor replacement, etc. make it a liability for OEM's vs. the good it can do. Of course the tables turn for those of us who know it's there and clean it out with system service.

But this stuck in the 1970's site doesn't have a Fing clue on how debris moves in a AC system. I just want to scream at them: "Follow the oil stupid!" Specifically small grit that makes it through the orface tube 'screen' continues on it's way back to the compressor with the oil moving in the system. Add a "Flooded" evaporator that is returning some liquid freon to move the oil through it and the derbis comes out of it. If the evaporator "distilled" everything as they claim it always does: well this 'stop the debris via distilled freon' only happens when the system is low on freon, yes the debris stops in the evaporator and there would suddenly be a lot of debris from the oil being stuck in the evaporator and not oiling the compressor.

Note: A failing compressor can throw debris back into the suction line. Yes, Flush everything!

At the end of the day this isn't the 1970's. The filter would be MORE EFFECTIVE at the INLET of the modern R134A thin tube condenser! This way it would save you replacing the condenser because you can't flush modern parallel flow condensers effectively. If you don't replace the condenser melted teflon rings debris start to move when things get hot... maybe Teflon and black death make filters ineffective in this "hot" location where melted liquid teflon is flowing... (Specific to our compressor designs YMMV for use of Teflon.)
 
I thought about going with an TXV instead of the orifice tube, but am going to stick with the changes Ive made so far. The conderser is from a 2014 Ford Super Duty (gasser), its a larger than stock 6.5. Its a modern parallel flow condenser and with the orifice tube in the evap I think it will blow snow balls when done (I hope :) )

On the filter, your saying to put it before the condenser right? It would be easy to do at this point.
This type filter? http://www.ebay.com/itm/NEW-Four-Se...uid-Line-/151268937131?_trksid=p2054897.l5661
 
Oh, just wanted to say to. It looks like anyone could move their orifice to the evap if wanted. If your doing a/c work anyway why not? WW brings up a point about a potential hissing noise though. I'll turn the radio up to fix that.
Moving it should help a/c perform better.
 
If your lines are insulated properly it isn't much of a concern. Insulation on your liquid lines and accumulator is often overlooked, but makes a HUGE difference in A/C performance. I know 2 years ago we took a road trip towing our travel trailer, and I had to run the A/C on fan speed 3 inside air for the front, and fan speed 2 for the rear to be remotely comfortable. This year on our trip I was running the front on 1 or 2, the rear on low, and outside air, and we were FREEZING! Only changes made to effect the performance was I insulated the accumulator, and my liquid lines from the orifiec back to the evap. I have been contemplating moving my orifiec tube to get a tad more volume in the system, and downsizing my orifice to the .062 to keep it from freezing up when running 70-75.
 
THEFERMANATOR said:
If your lines are insulated properly it isn't much of a concern. Insulation on your liquid lines and accumulator is often overlooked, but makes a HUGE difference in A/C performance. I know 2 years ago we took a road trip towing our travel trailer, and I had to run the A/C on fan speed 3 inside air for the front, and fan speed 2 for the rear to be remotely comfortable. This year on our trip I was running the front on 1 or 2, the rear on low, and outside air, and we were FREEZING! Only changes made to effect the performance was I insulated the accumulator, and my liquid lines from the orifiec back to the evap. I have been contemplating moving my orifiec tube to get a tad more volume in the system, and downsizing my orifice to the .062 to keep it from freezing up when running 70-75.
Click to expand...

Got a picture? I am not sure what is what on the A/C system. I would not mind attempting this insulation mod.
 
DieselCash said:
Got a picture? I am not sure what is what on the A/C system. I would not mind attempting this insulation mod.
Click to expand...

No pictures, but basically wrap the A/C line coming from the condenser to the evap in some 1/4" foam insulation tape, and then wrap the accumulator(silver canister on the firewall) in it as well. From the factory all of these lines were insulated, but after about 10 years it is all gone.
 
Here's a poor pic of the acumulator insulation. It sould have a top piece too. The line from condinser to evap you can basically wrap any insulation around it. I think the silver reflective stuff would be the cat's ass.

acumulator insulation.jpg
 
I don't have the fancy boot anymore for mine, so the silver reflective stuff is what is on all of mine. It made a HUGE difference in A/C performance. I still need to get out and wrap some more of the suction lines, anyplace you can not introduce heat helps.
 
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