AC Condensor

lookforjoe

lookforjoe

True Classic
Went back to TonyK's excellent thread, but it's now locked.

I had to work on the AC again. I get high side pressures around 400psi at idle!!! The general consensus is that the condensor is just too small to provide adequate dissappation (sp?). I can try moving it close to the rad, so that the two rad fans have greater effect, but I'd rather install a larger condensor, since I need to remove it anyway to fix the minor leak at the line fitting.
Old pic, but I have three fans - two on the rad, and this one hooked up to the stock AC fan circuit

IMG_7363.jpg


Has anyone on here sourced a larger condensor that works? How about joining two together?
 
Check the

Expansion valve.

Looks like mine has packed it in as well.

If the valve does not open the pressure will go High and little cooling will happen. At one time I had lower temps like 35 degrees F, but the other day with the car out I only had 20 degree differential. Pressure was high at Idle 360 PSI, So the valve isn't opening. Will have to order another. You can order a small condenser and put it in series it will be made from aluminum. Try Nostaglic AC they have a wide range of universal condensors. Then make up two new hoses to adapt it to the X's system. Change the expansion valve too they also supply them and they are only $20.

TonyK.
 
TonyK said:
Expansion valve.

Looks like mine has packed it in as well.

If the valve does not open the pressure will go High and little cooling will happen. At one time I had lower temps like 35 degrees F, but the other day with the car out I only had 20 degree differential. Pressure was high at Idle 360 PSI, So the valve isn't opening. Will have to order another. You can order a small condenser and put it in series it will be made from aluminum. Try Nostaglic AC they have a wide range of universal condensors. Then make up two new hoses to adapt it to the X's system. Change the expansion valve too they also supply them and they are only $20.

TonyK.
Click to expand...

Ditto on that, exactly what he said
 
TonyK said:
Expansion valve.

Looks like mine has packed it in as well.

If the valve does not open the pressure will go High and little cooling will happen. At one time I had lower temps like 35 degrees F, but the other day with the car out I only had 20 degree differential. Pressure was high at Idle 360 PSI, So the valve isn't opening. Will have to order another. You can order a small condenser and put it in series it will be made from aluminum. Try Nostaglic AC they have a wide range of universal condensors. Then make up two new hoses to adapt it to the X's system. Change the expansion valve too they also supply them and they are only $20.

TonyK.
Click to expand...

IF the AC condensor has copper lines, can't I just cut a second (used) one down & splice two units to make one larger unit? That would make more sense to me.

Any chance you have the appropriate PN for the expansion valve? Last year I put a used Volvo one on...

EDIT: Looks like this one

5294_9873W.jpg
 
LarryC said:
because I just order one (based on TonyK's suggestion a while back) and just received it. Looks right. Also got the Jag drier from Rock Auto and it looks about right, too. One female side, one male. And the male is on the condenser side, so should be easier to deal with that hose.

Expansion valve: http://www.nostalgicairparts.com/air-conditioning/o-ring-expansion-valve-52.php
Click to expand...

Thanks Larry!

I'd like to do the drier as well - do you have the listing for that? Is it the CAC2338?
 
Quote "IF the AC condensor has copper lines, can't I just cut a second (used) one down & splice two units to make one larger unit? That would make more sense to me."

Yes you can but it must be silver soldered not lead soldered.

Do your best not to install any aluminum parts in the system as the new oil that is compatible with R134 if it gets moist becomes very corrosive. Hence the reason so many new cars loose evaporators and condensers. With an all copper system the Dryer plays less of a required part in the system. If you go to the Rock Auto Site and look up the dryer Larry found for the Jaguar it looks like a compatible fit.

TonyK.

Grimsby Ontario Canada.
 
Thanks for the soldering tip - I have silver solder, so not a problem.

I'd rather splice two copper core units than add an aux. aluminum one - so I'll check Bayless for a used condensor.
 
Condensor arrived from Bayless, expansion valve came from Nostalgic, just waiting for the drier, then I'll pull it apart & make my hybrid condensor.
 
What geometry are you going with?

The stock condenser is about 22 x 7. Are you going to make a 22 x 14? Or stack two? Take detailed notes and pictures!
 
Have a couple of cautions for you here.
1/ Increaseing the length of the condenser pipe run can sometimes increase the pressure drop in the condenser, so though you have more metal you still have a high pressure.
2/ You indicate you have three fans on there.
Try and find a way to mount the AC condenser up against the radiator and then shroud or fill the gap between the two at the eedges with a strip of foam rubber. this prevents the air bypassing the AC condenser coil
3/ Wire one of you main fans to come on with the AC cooling call (unless you have a head pressure control switch instaled for the fan). Leave the other to cycle on the water temp temp sensor.
I have had no problem with the standard condenser in North Queensland Australia ( topical noth) if this is carried out.
4/ The previous comments by others regarding the TX valve are well made. I beleive you used a TX valve from another car (volvo) Not neccersarily a good move unless you know it has the same refrigeration capacity and thermal element charge.

BM Oz
 
Thanks!

The expnsn valve I used was the same part & design, just a used one.

I'm replacing it with a new one.

My intention was to lengthen (increase the height of) the condensor, and as you mention, reduce the spacing between the units - that changed when I installed the VW rad. I will do away with the forward fan if I can, and revert to one Rad temp fan, one AC fan as it was originally setup (both mounted on radiator).

The forward fan is tied into the factory AC fan wiring. The two rad fans are in parallel, and can be manually activated, otherwise they come on around 190ºF (engine temp) - I used a low temp BMW inline sender because it's in the return hose not the radiator.
 
Cut two rows off the condensor & bridged the two condensors

IMG_1235.jpg


IMG_1236.jpg


fabricated a revised lower pipe from the two units, silver soldered a tab on each side to bridge the end plates

IMG_1237.jpg


IMG_1238-1.jpg


Have to come up with some 10mm copper tubing - one of the replacement loops I cut from the unused sections didn't hold up & I have a pressure leak - didn't show up when smoke tested.

So, tomorrow I have to take out the rad again and R&R the condensor, see what I can do to seal/repair that one loop.

Have to also cut the rad support plate in half longways, the condensor now is almost the same height as the rad.
 
Rad / condensor sandwich

IMG_1240.jpg


re-soldered the two bridge loops

IMG_1241.jpg


overall fit

IMG_1242.jpg


staggered support brackets

IMG_1243.jpg


IMG_1244.jpg


lower support

IMG_1245.jpg


Jag drier compared to Fiat - basically the same except for the bracket

IMG_1246.jpg


IMG_1248.jpg


Rep;laced the expansion valve as well.

System held vacuum, so I added oil & charged the AC. With the condensor so close to the rad, the engine temp climbed to over 200º idling with Max AC. vent temp was only 70º - Low side was 20psi, high side was around 350psi. Mid afternoon, temps in the 90's.

Had to rewire one of the two fans - only one of them was running full blast. Ran it back through the stock relay, as my manual override was also non-functional with my last revision. After that, vent temp dropped to 60º, and engine temp didn't climb too much over normal.

I then added the small fan back in front of the condensor, and wired it to the standard AC fan circuit.



Now blows a nice 60º at the center vent. :rolleyes:
 
Drove the X for a two + hour round trip to a swimming hole near New Paltz, NY. Midday, the ambient temps were in the 90's.

This is my operating temp on the highway
(note: oil pressure gauge reading is inverted due to VDO sender)
IMG_1249.jpg


vent temp

IMG_1250.jpg


By around 5pm the ambient temp had dropped sufficiently that my vent temp was 60º.

The problem now is that with the condensor close to the rad, the operating temps at idle climb well above normal, especially with the AC on. Sitting in traffic on the highway, it went to around 3/4.

I'm wondering if I should vent the frunk.....
 
Overall, a nice experiment.

Do you have any post-mortem thoughts on the condenser? The pressure still seems a bit high given that you have increased the areas of the condenser by around 30 percent. It must be close to 200 sq. inches by now. Closer to 240 would be ideal from what I can calculate, but that is not going to happen easily. Still another 30 per cent seems like it would have given somewhat better performance. With the high radiator temperature, I wonder if the net CFM is down somehow negating the added area on the condenser.

By the way, are the condenser fittings No 8 and a No 6?

I am glad the Jag drier worked out. It just seemed to me that a high end British car of the same era might use similar equipment. Otherwise there was no reason why I looked up the Jag.
 
Hussein and Larry....

I tend to agree and the industry does as well... the real "secret" to better operations and efficiency is the most condensation you can get for the little-est effort.

So... don't hammer me... but ya know I would go with an after market system and with that thought in mind... I'd also place the condenser elsewhere.

I kinda like the LOOKS of Cozzoi's Dallara Wing... Certainly thick enough to house the condenser, a couple of flat fans and the uprights are robust enough to handle the wiring and plumbing as well.

One of you could be the first on your block!



P.S. That's the WING on the right! George is the ugly guy on the left... and the three "chicks" in the background are my daughter-in-law, Wendy, hidden partially is Paige-y age 7 at the time... and the Blonde is 15 year old Piper, now 17.

AGAIN... the WING IS ON THE RIGHT!
 
I have to go back to the shop & hook up the gauges again now that I have all the fans operational. It's been so hot & humid here!

The condensor line fittings (the nuts) took a 3/4 & a 7/8 wrench, don't know what that translates to in terms of a numbered line size.

The AC certainly gets cooler now that it ever did, and I'm happy with that aspect. Maybe new condensors would have been less of a restriction, with better finning. Not sure what I will end doing regarding improving the air flow. Cutting the back wall & venting the frunk lid certainly seem like a viable method - didn't they do that for some track/race versions? Hard to imagine them relying on the crappy air flow situation under there...

Maybe an additional extractor fan to draw the heated air out of that pocket? I dunno.

Tony - I'm not moving the condensor to the rear, that would just look like crap & make it difficult to work around.

EDIT:

After looking at the condensor spacing on my wagon..

XRFMIC0030.jpg


I'm thinking the first thing I need to do is move the condensor a little further away from the rad, and see how that goes. I have enough give in the flex lines to the condensor to allow for an inch or more of movement.
 
Last edited:
Sealing between the airdam and the face of the condenser

During idling sessions you may be experiencing looping of the air through the fans. Instead of getting clean cooler air from the front you may be getting exhausted air looping back in front of the condenser/radiator assembly.

You might consider making a closure tray running from the back of the air dam to the bottom of the condenser/radiator making the "loop" much larger and tending to get more "fresh" air in stopped traffic.

On a Fiat 850 there is a tray in front of the radiator for just this reason and when people remove the tray the cars tend to overheat.

Just a thought.

Karl
 
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