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Parallel flow condenser

Started by 1980sdga, 29 June 2011, 07:50 PM

1980sdga

Thanks. I still have some issues that bother me. The shop that vacuumed/charged it for me only held vacuum at 30 (Not sure the value  :P) for a few minutes.  They only charged me $55 so I didn't press the issue when they said it was OK...

I plan on getting my own vacuum pump and some gauges. I probably have about 400 miles with the AC running. Haven't needed it much as of late... Now that I've seen some "professionals" vacuum/charge a system I have a better idea about how to do it. I'll probably run it a few hundred miles and inspect the orifice tube, do a thorough vacuum and recharge. They measured in 2 lbs of 134a in 8 oz increments until it started cooling so I also have some volume numbers.

I'm not sure how often, or even if, the compressor is cycling going down the road. I don't think it has cycled too soon with the system still pressurized like you mentioned, Ken. I accidently manually cycled it too soon once and the belt gave a squawk before the compressor started. Probably don't want to do that too often! I was thinking about installing a temporary light that would come on when the compressor is engaged so I can see when/if it's cycling.

Here's a vid of me manually cycling the compressor:

http://www.youtube.com/watch?v=G2XnY8lmC2o&feature=mfu_in_order&list=UL

Cameras help me a lot when working alone  ;D

I'm working out some mechanical stuff now, making sure no hoses are chafing etc. I made sure the condenser isn't rubbing against anything like you suggested using sliced heater hose parts to prevent any chafing.

I was worried about the compressor bracket because it is home made but I think it's pretty solid. I need check all the bolts for tightness an inspect the welds.


KenM

Hey Jon, first off, if your system doesn't hold a vac then you have a leak, need to do a leak test before you vac it out. Second, it's impossible to get a vac of 30", the most you can get down to is 29.99995 or some such, so they either need to get better instruments or more likely were just looking at their gauges. You need a vac tester to be accurate and to be sure that it's holding, it should hold a vac without rising appreciably for at least a couple of hours if the system is tight. I think as Bolbol was saying earlier that your thermostat should not cycle the compressor on too frequently, as you found out they don't like it when you do though. Sound slike you're getting close to done.

1980sdga

I guess I worded it wrong but it held vacuum for several minutes without leaking down.  The first time they vacuumed it I found a leak and had to tighten a fitting which seemed to fix it. After charging they went all over it with a sniffer and all looked well.  I made sure they sniffed the area behind the instruments REALLY WELL  :D  It's just such a PITA getting in there to tighten stuff up!  Hopefully running won't cause any leaks.

I'm not sure if it says anything but when running at an ambient temp of 85 F the receiver was 125 F and the accumulator was 44 F.

I really appreciate the input! 

Big Tiny

Hello Jon,

Would like to know how this setup is going, really thinking I need to consider this same route.
I'm in QLD AUS, its getting hotter here, and the 76 280 is struggling to get cool.
Ive spent alot of time and cash on this at the local aircon shop, to no avail.

I'm starting to think the condensor is just no good with the R134A.

Brett

1980sdga

Hey Brett,

My original factory setup was working extremely well before I did this work.  Unfortunately, here in the states we got R4 compressors which weren't the greatest to start with. r134a runs at higher pressures so it's just too much of a load on the compressor and they fail. I figured since I was changing out the compressor I'd make it easier to service the whole system by installing the orifice tube.

I had no complaints about the performance of the factory system and I'm in the southern US so the AC shop should be able to sort it.

I would start by making sure all your components are clean. The evaporator (The "radiator" in the car) needs to have clean fins and good airflow to work well. This goes for the evaporator as well. I'm sure cleaning the evaporator is often overlooked because it's so inaccessible.

What work was done to the car? 

I have a label on my car that has the oil and refrigerant volumes so I'll post them.

So far the rejiggered system is working well!  It started getting cool here so I'll have to give it some thorough testing next summer.

Big Tiny

Hello Jon,

Thanks for the reply.

Long story, short. The old M110 engine had a brand new compressor (York?), was flushed, new drier, charged R134 A, 1500 bucks later, still no good. Ac prior to that hadn't been functional for maybe 10 years, due to a seized compressor. I had Icy Cool come back and look at the car, they said everything was within "spec", total bull, it was useless on a hot day. You had to put windows down. A new condensor fan helped ( a little)

Now wind forward a few years, Ive now put a lexus V8 in her, along with, lexus 10PA denso compressor (NEW), we have now replaced the TX valve twice, re gassed 5 times ?.
Its running R134A, about 1 kilo, ac shop has tried, 750, 800, 1kg etc.

Now my only conclusion is the condensor is not up to the task, it is very clean (externally), radiator has been rebuilt, brand new 16 inch thermo, I tried two thermo's at one point, I think that wa slightly better so may go back to that at some point.

On the highway, at night after about 20 minutes, sitting on about 110, the centre vent wil pull down to around 6 degrees. Now that is on max cold, fan speed at lowest setting.
Generally during the day, it struggles to get under 10 degrees, and takes a while to get there, the side vents are closer to 20 degrees. Remember this is on the lowest fan speed, if you select the higher fan speeds, temp just goes skyward.

Just as a test, I just ran the car, and sprayed 50/50 water/meth onto the condensor, after about 5 min I was seeing 3.6 degrees at the centre vent. That was while stationary on the drive, about 25 degree outside temp. I really think this points to condensor efficiency at being on the very low side, its struggling (due to R134A ?) ( Dirty internally ? ). Now a new tube and fin might do the trick, but for the trouble its seems more logical to go with the newer parallel design, despite the few fitment issues.

I would really appreciate any input.

Regards,

Brett.

Big Tiny

I just phoned and MBV in NSW, and spoke with a chap there. He specifically said they run Hychill gas in all there Merc's, and that it runs more efficient than both R12, and R134A.

Has anyone had any experience with Hychill gas ?

1980sdga

I don't know about alternative refrigerants...  My gut tells me just to stick with either r12 or r134a.  Our factory systems will work pretty well with 134a which is what I decided to go with. I think the only downside to 134a is that it works the system harder but this shouldn't be a problem with your new, updated compressor.

Here's a vid of my temp drop with a hot cabin at idle:

http://www.youtube.com/watch?v=KoBkf3xqH78

You should really start a thread on your Lexus powered 116  ;D  That sounds really cool  8)

It's a shame you've spent so much money and the AC still isn't working... Replacing the TX valve is a tough job and you've had it done twice!

It actually sounds like your heater is working at the same time as the AC, especially the higher vent temps at the outside registers. But it sounds like you have checked it out pretty well... I have ACCII (Or KlimaI, or Airtemp II depending on who you ask  :P) which "blends" warm and cold air to maintain temp. Maybe your system does something similar?

Did you check the side vent temps while spraying the condenser?  I'm mainly asking because a 10 deg difference sounds like a lot. My side vents run a little warmer but not that much Maybe 5 deg at the most.

I would hate to see you spend more $$ and sweat and still have a poor system. I would troubleshoot the entire heat/air system really well before throwing more at the compressor/evaporator/condenser part of the system.

I was also wondering if you had some type of bad failure that filled the system with debris from a bad compressor. This would foul the TX valve in short order even after a replacement and from what I understand, it's almost impossible to get it all out even with a good flush.  An orifice tube retrofit would allow for simpler/cheaper servicing in the future plus it adds another filter to catch debris. Plus a P-flow condenser can't hurt.

Good luck and keep us posted!

koan

Quote from: Big Tiny on 25 October 2011, 11:17 PM
Has anyone had any experience with Hychill gas ?

Yes, works well.

koan
Boogity, Boogity, Boogity, Amen!

1980sdga

Is Hychill a propane based refrigerant guys?  Here in the states we get into issues with ozone/global warming/plague of locust preventing gas recovery machines that pro shops MUST use or face fines. All US cars have used 134a for about 20 years so most shops won't work with anything else because it contaminates the machines.

There are "alternative" refrigerants available here but they're mostly for do it yourself guys.

Big Tiny

Jon,

Yes the lexus conversion is worth a thread on its own  :D

The heater system has been bypassed to prevent dilution of the "cold air", My side vent temps, are probably closer to 7-8 degrees greater, but have only checked them a couple of times.

When I chilled the condensor with meth/water, and the vent temps went straight down to 3.6 degrees, about 3 min time lapse, I then assumed that the tx, evaporator etc side of things was working.

I also have a SC400, with identical engine, and ac compressor, so I know what they should do when working well, its really good for comparison. Now the only real difference between the two systems, is the lexus has a huge alloy parallel flow condensor, it really pulls down very quickly regardless of outside temp, they also run a massive hydraulic fan setup, that really shifts some air, probably twice that of the 16 inch electric I have.

I actually spoke with Hychill in AUS, his name is Ross, he put me in touch with a chap in Northern NSW, who has apparently been in the business 40 plus years, and swears by it. Anyway going to see him early next week, to get a diagnosis, and see what he thinks of the setup.

Oh just a side note, I managed to get the air vent temp down to around 5 degrees at idle yesterday, without the water/meth trick, took a while though. But thats what its does, it will get cool if you start the car and everything is cool, leave bonnet open etc. But take the car to the beach, let it get super hot, and then you have no chance, it aint going to get cold, windows down time. I don't have such a problem in any other car.

Koan, will hopefully I will have this gas in the car soon and see how it goes, have only read good things so far.

Brett

1980sdga

I figured I'd update this since I've done some more work and it's getting HOT here in the Southern US.

I've had a little leak on one of the hi side hoses that which I FINALLY addressed. Re-crimped a new end on it and all seems well. I also changed orifice tubes from the Ford "blue" to a GM "white" which is what Bolbol used with his conversion.

So far so good!:



Ice in the engine compartment!  I think it's a little low on charge with only 24 oz of 134a but it's cooling about as well as my modern cars!

Went on a 100+ mile trip the other day and all seemed good to go.

Squiggle Dog

I am so glad that you are doing all of this work before me! I'm moving from Washington state to Arizona on July 1st (during the summer) and will need to get my air conditioning upgraded and working as soon as possible once I'm down there (as well as fully converted from automatic climate control to manual).

I plan to upgrade to a parallel flow condenser and Sanden compressor as you have and will run R134a. Let's hope I don't bake alive before I get operational air conditioning!
Stop paying for animal cruelty and slaughter. Go vegan! [url="https://challenge22.com/"]https://challenge22.com/[/url]

1967 W110 Universal Wagon, Euro, Turbo Diesel, Tail Fins, 4 Speed Manual Column Shift, A/C
1980 W116 300SD Turbo Diesel, DB479 Walnut Brown, Sunroof, Heated Seats, 350,000+

1980sdga

These guys are supposed to have a Sanden bracket for our OM617's by the end of the month:

http://www.klimakit.com/product-o/

I'm interested in seeing it because you see how difficult it was mounting that SOB on my engine!

Squiggle Dog

Quote from: 1980sdga on 09 June 2012, 07:45 PM
These guys are supposed to have a Sanden bracket for our OM617's by the end of the month:

http://www.klimakit.com/product-o/

I'm interested in seeing it because you see how difficult it was mounting that SOB on my engine!

YES!
Stop paying for animal cruelty and slaughter. Go vegan! [url="https://challenge22.com/"]https://challenge22.com/[/url]

1967 W110 Universal Wagon, Euro, Turbo Diesel, Tail Fins, 4 Speed Manual Column Shift, A/C
1980 W116 300SD Turbo Diesel, DB479 Walnut Brown, Sunroof, Heated Seats, 350,000+