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910Esprit

Project A/C R12 to R134 in a G car

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How many people out there have working aircon in a G car? 

 

After a 15 year gap, I'm going to try to get my A/C up and running reliably.   I'm going to attempt a full R134 conversion replacing the R12 SD508 Sanden with a R134 SH09 Sanden.   As R134 typically needs a more efficient condenser than R12, I used a smaller capacity compressor of approx.. 5.5 cu ins vs. 8 cu ins.   This should give me an improved compressor/condenser performance, whilst presumably still being large enough for an Esprit cabin.

 

Actually the main reason I went with the SH09 was because it was £15 new off Ebay and looked more or less the same as a SD508!   Its physically shorter, but with a minimum amount of spacers its now mounted and looks 'factory'   The pulley is also a little smaller, which will hopefully improve low speed performance, but luckily the original belt still has enough adjustment to tension correctly.

 

I 've also removed all the old hoses as they appear fairly brittle and frayed.  It also liberated maybe 1oz of unwanted mineral oil (and the original R12 hoses are more porous than modern barrier hose).   The job wasn't quite as horrendous as I'd previously remembered.   Also as a major achievement I've managed to undo all the old unions without any damage to the Evaporator or delicate condenser (Drier will be replaced).  

 

Looking at the internet there is conflicting info on the differences between an R12 and an R134 expansion valve, so I will leave asis and see what happens. 

 

The next steps....   I think I now have done enough research to understand the difference between all the different hose sizes and the mixture of old style/new style fittings and the adapters and reducers etc I need.   These have now been ordered....  I'm also planning to crimp my own hoses using a portable beadlock crimper.

 

I'll post a further update in a few weeks time when the parts arrive.  If I ultimately succeed, I'll detail the exact inventory of parts and the mods required.

 

If anyone has done anything similar and has any good advise please let me know.

Edited by 910Esprit

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Steve

I have been repairing car ac for 30 years.

I have just done the same job I replaced all pipe work except the drier to ex valve i used airoquip and re used the original fittings on the suction side i had r134a hose in stock for the liquid line and crimped new ends on. I also flushed out the evaporator  there will be old oil in there. you will need to get some oil which is suitable for for 134a as it is carried around the system  with the refrigerant.

As far as the condenser is concerned there are no issues it is well sized for 134a remember you have 3 fans running with the air con and it was designed to run in hotter climates than manchester.

You will need to add a egg cup full of oil to the system when you recharge i used a sanden comp of an excel these will run on 134a ok providing as you use the correct oil. The cooling and lube of the compressor is taken care of with the cool gas and oil on the suction pipe so all the systems that are running short of gas are not doing themselves any favours..

The ex vale has no issues it will work fine .The 134a requires green O rings as std ones will fail as the gas will decompose them. Lotus were good as they mostly used flare type fittings most of the time.  Please don't hesitate  to get intouch if you need more info glad to help.

PS i will wrap the two pipes together in the engine bay with insulation so they don't get rubbed through and to insulate from engine heat.

andy b

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Thanks Andy - I'm sure I'll be picking your brains  (as I'm largely just making it up as I go along - with the help of the Internet). 

 

NB - I can see a gap in the market for somebody specialising in Classic Car A/C with a trade counter that carries all the fixtures, fittings & Hoses to upgrade.   Perhaps you should expand to cover the NW! 

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retired now but glad to help having said that i still carry the gas the fittings i use are now obsolete uni part took over the company i used for fittings and they  dumped the lot  in the skip. but i had enough left to do water hoses on my boat and the turbo esprit.

when i bought the turbo off ebay the air con was in a cardboard box not the easiest job on the turbo. if you need to ring 07831136802.

andy b 

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Check out Hy-Chill gas. My S4 system couldn't hold the factory gas for more longer than the summer season. Since swapping a few years ago no more leaks. Bigger molecules, lower pressure and only a third of the charge by weight.


DanR

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Danny

Interesting post i have worked on fridges with R600 always nervous when i silver soldered joints. incase it went bang.

I havent a clue where you can get that in the uk for commercial use.

 

Remember the bond film with the flaming aerosol killing the snake, Thats what hychill refrigerant is flammable gasses.

 

I do know that all councils scraped all commercial fridges with R600 in there school canteen's due to fire risk health and safety gone mad.

What can happen when you charge a system which has not worked for a while  the system can leak. Then on a second charge the oil in the system can stop or slow down the leak.

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Hey Andy - What would be an equivalent of Sanden SP15 PAG oil?  -  That's what's already in the compressor, so I need to add your 'egg cup full' for the parts that have been purged/replaced...  seem to be 3 standard viscosities 46,100 & 150. - should have googled that one - Its PAG100

 

Question 2 - If its a virgin install of an 'empty' system with new compressor, hoses, drier would you add anything in addition to the gas?   (e.g. would you add dye or anything else)

 

Cheers    

Edited by 910Esprit

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I am currently fitting A/C onto am 82 Turbo which doesnt have it at all.

 

I already had the heater assy out (no mean feat!) as it was clogged up and the controls were snapped. So I got one with an evaporator from Lotusbits. I also already had the rad tray out to replace the rad.

 

I bought a condenser which is a parallel-flow aluminium type. Its not as long as the original but hopefully will be OK. Its also really light.

 

SD508 I already had from an old project.

 

Comp mounting bracket (front and rear) and 3-groove pulley from Lotusbits.

 

Control unit with potentiometer from China.

 

So far so good. Now the fun starts. The first big issue was the compressor does not fit because the alternator is in the way. This means moving the alternator upwards. To do this the later alternator mounting bracket needs to be used. Now, to fit this, the auxiliary housing needs to be changed! What fun! Luckily Lotusbits came good at a very reasonable price. Also the alt itself is different but not too bothered about that as I was going to get it reconditioned anyway so I traded it in. To be honest if I was aware of the need to change the aux housing I would not have started this but then again I like a challenge!

 

More fun, the cooling plumbing around the thermostat is different because the junction pipe fouls the compressor. I bought a new pipe from Lotus which thankfully was one of their discounted items. I am not 100% sure how it fits and am about to make another post about this.

 

One issue I have not yet resolved is the outlet from the evaporator is a huge size 12 flare, but the inlet to the SD508 is size 10. So, not sure what to do about this, any advice welcome AndyB. I think they used size 12 hose on the originals so there must have been some kind of reducer on the compressor end? Flare fittings seem very hard to get these days. I bought some from a guy in the USA on Ebay. 

 

Another issue, the pipes I believe originally ran down the left-hand sill. But the 2 holes for the pipes on my car are on the right hand side of the chassis! I will need to find another route.

 

I am looking for a place to get fittings and hose as I have not bought these yet and not sure how much I will need yet.

 

Steve what year is your car? You might be able to answer several questions I have about the original installation.

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Ah yes, I had the massive evap flare issue too....   A helpful supplier in the states has got me a #12 Flare to #10 beadlock fitting..   (the pipe is #10 (5/8 ID) , Lotus (or should I say Aeroquip) also originally stepped down at the evaporator fitting.

 

Other options - reuse your original fitting as it will be in mint condition (unless you took a grinder to it like me - before I realised how precious it was....). -oops you don't have the original!

 

There are also #12 flare to #12 o-ring adapters, then you could use an inline 12# to 10# adapter which are 'common'.  

 

Andy W - Mine is an 84, good to know I have a compadre doing the same as me - although I don't envy the scale of your conversion!

 

Yeah - That was my point above - there seems to be a dearth of UK suppliers (unlike the states where you guys are spoiled for choice).   However have a look at Burgaflex UK, I'm going to give them a call to see if they have a trade counter or distributors. 

Edited by 910Esprit

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Ah yes, I had the massive evap flare issue too....   A helpful supplier in the states has got me a #12 Flare to #10 beadlock fitting..   (the pipe is #10 (5/8 ID) , Lotus (or should I say Aeroquip) also originally stepped down at the evaporator fitting.

 

 

 

Funnily enough I just received an email from a contact in the US who has confirmed he has a #12 to #10 step beadlock fitting on the way to him! I found this the other day online but they would not ship it here so I asked him to order it instead. So should be OK on that one. I do have the original fitting actually with a short piece of cut-off hose but not sure if these can be reused, they are not beadlock but swaged or something.

 

http://www.4seasonsuk.com seem to be a big supplier but I have not contacted them yet. Their online catalog lists pretty much everything.

 

Are your hoses from the comp routed under the engine and through 2 holes in the V of the chassis on the left? I cant do that if so, because the 2 holes are on the right as mentioned above. I have not yet worked out how the hoses get from the sill to the evap or condenser.

 

I noticed they used flare gaskets on the evap connections. Do you know if they also used them on the comp connections? Goodness knows where to get those from.

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I'll take some pictures of the pipe routing - its actually pretty straightforward.   (goes in sill at petrol tank hole & exits in front of wheelarch and simply has a carpet covered cover over them)      The only place that uses a copper flare gasket is the evap.   TBH if you made a copper washer from sheet, it would just press into the flare profile?   Again, some of the US sites I've seen have flare gaskets.    Any of the commercial hose places e.g. Pirtek could reuse the fitting with a new swage

Edited by 910Esprit

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I'm really interested in this thread but know that I'm not going to tackle this myself.

 

Are there any specialists who will convert an older car to the latest air con systems at a half decent price?

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I'm really interested in this thread but know that I'm not going to tackle this myself.

 

Are there any specialists who will convert an older car to the latest air con systems at a half decent price?

 

I think you can get away with doing very little. My Ferrari 328 has the same SD508 compressor and a much smaller condenser and evaporator than the Esprit and I just retro-fitted with R134a, using the special oil which is compatible with old systems and did nothing else to it. The system works fine, at least in UK hottest temperatures.

People moan about A/C with 134a on forums but generally they are from hotter areas than the UK.

 

Incidentally the system on my previous Esprit, an Essex-spec, with R12 was the best car A/C I have every come across, it chucked out air at -2 degrees! The sizing of the evap/condenser and hoses etc is very generous on these cars so the losses from going to R134a should still leave it pretty good. 

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This was my first thought, but a 30 year old system that has been out of commission for many years, with flakey looking pipes didn't seem a reliable starting point.   If I pull it off Barrie, I'll publish the end to end process.  In reality, most of the stuff so far is pure mechanics, the only twiddly bits will be flushing, vacuuming & charging, which any 'modern' A/C place could do.  

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This was my first thought, but a 30 year old system that has been out of commission for many years, with flakey looking pipes didn't seem a reliable starting point.   If I pull it off Barrie, I'll publish the end to end process.  In reality, most of the stuff so far is pure mechanics, the only twiddly bits will be flushing, vacuuming & charging, which any 'modern' A/C place could do.  

 

Thats definitely the best way and will end up being leak-free hopefully because the old, porous hoses will go. But as Barrie has ruled out DIY this places a different slant on things and having the hoses all replaced by a dealer might be prohibitive. It might be cheaper to live with a leak if its not too bad.

 

The dry sump cars (I used to own one) had a different compressor mounting arrangement which is even more difficult to access, its slung on the bottom left side of the engine. In fact as I write this I have realised why my hose chassis holes are on the right. It must be a dry-sump chassis. Which makes sense as it would have been built alongside dry-sump cars which all had A/C.

 

I am wondering whether I should replace the shaft seal on the SD508 while its on the bench.....

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wow there is a lot of interest in this. to much for my small brain.

Copper gaskets for the flared ends go to your local refrigeration supplier they should stock them all they are is a flared copper pipe then cut off.

I can make these for you as i still have my flare gear but get them local if you can they will be nice and soft to crush between the two flares.

Any joints you do smear some oil around it threads nuts and flair faces.

If you have the original airoquip fittings. cut them off leaving some hose in there get them in the vice spray with release oil and leave for a couple of days.These may come apart THEY MAY BE LEFT HAND THREAD I had to set fire to my ends to burn out the hose before they came apart. I then sand blasted them and re fitted on the new hose. Always cover everything in oil hose and fitting it ant easy you would think it will never go together.  If you have the evap out flush it now and then seal the ends. if any of you use second hand parts always flush out and blow through ideally with dry nitrogen. You could use brake cleaner spray a load of it down the open pipe then push it through with dry air or nitrogen the brake cleaner should pick up the old oil rubbish in the  evap  or condenser  and push it out through the other open end.Store it in a dry place to let the brake cleaner to evaporate off before sealing up ready for use. Any specific questions try tel my mobile is on an earlier reply on this post. andy b

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Thanks Andy b. Its great having expert advice! 

 

I phoned 4Seasons yesterday, The guy explained at great length how they had been taken over and nobody there knows anything about A/C as they are now a general car parts supplier. But they do seem to have many of the bits and pieces in stock so I will be making up a shopping list. They are a big wholesaler so I would expect prices to be lowest.

 

I need to guesstimate how much hose I need, thats going to be tricky. Also looks like I might need to drill 2 large holes in the chassis which is even trickier!

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#10 = 135 inches

#8 = 214 inches 

#6 = 28 Inches (drier to condender)  Don't know about #6 to evap as I'm leaving that one

Why holes in chassis?  

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Thats great info thanks!

 

The 2 holes through which the hoses pass (at least I assume thats what they are for) are on the right hand side of the chassis on my car and they need to be on the left I think because the hoses run through the LH sill.

 

They are located in the V section just behind the rear end of the central backbone.

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As my ac came in a box and the pipe work was cut of i run the new pipes under the engine with some insulation wrapped around them both. I don't think they run through holes in the chassis One of the 2 holes runs the link between the fuel tanks on the 82 turbo it is about 25mm and fits tightly in the holes with rubber grommets.so you could only put one hose through the holes but i could be wrong here can anyone take some pictures of the route of the ac pipes in the engine bay. having said that I don't think you would get the large suction pipe with fittings on and grommets in the chassis holes. But every day is a learning day. I think the suction pipe (the big one) from evap to comp was about 3.5mtre cost £108 from my local hydraulics man genuine airoquip as i wanted to use original ends (got it at cost i think as i installed his office ac) I have the liquid line here  comp to condenser i had to buy a full coil if anyone wants any i can sell you some i recon it will be aprox 4.5mtre but it is not airoquip it is 134a rated rubber hose the proper stuff. 

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OK maybe these holes are nothing do do with A/C pipes. Maybe the pipes simply run out through the spaceframe.

 

The pic shows the holes (on the right of the chassis not left) and the pipe is the fuel tank crossover.

 

Andy is the hose size #10 ?

post-16906-0-18640300-1404588806.jpg

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Measurements are actual hose cut length 

 

- Andy I will buy a length  I assume it isn't  reduced O/D?  How much do you want?  PM me if you prefer.  However as Andy says is it #8 or #10  (it seems that Lotus used #12 low and #10 high - whereas current Sanden  fitment would be #10 & #8?).

 

As previos - certainly on an 84 the pipes run through the sill - as below.   The routing through the engine bay just appears to get from a to b without any obvious planning! 

 

tank.jpg

 

cabin.jpg

Edited by 910Esprit

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Measurements are actual hose cut length 

 

- Andy I will buy a length  I assume it isn't  reduced O/D?  How much do you want?  PM me if you prefer.  However as Andy says is it #8 or #10  (it seems that Lotus used #12 low and #10 high - whereas current Sanden  fitment would be #10 & #8?).

 

As previos - certainly on an 84 the pipes run through the sill - as below.   The routing through the engine bay just appears to get from a to b without any obvious planning! 

 

 

 

 

 

Thanks for this, I will just route them out through the spaceframe without holes if thats what they did. I wonder what those holes in my chassis are for?

 

Yes they did originally use #12 for the low pressure because there is a bit of hose still connected to my evaporator and its #12. They must have used a reducer at the compressor end as the original SD508 has a size 10 low side port.

 

Going with the now standard sizes 6, 8 and 10 makes a lot of sense, the hoses will be more manageable. That #12 hose is huge!

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My thought exactly!  How they routed that braided Aeroquip I don't know....  I cut mine in 2 places to get out.   Yeah I was wrong before as I thought it reduced at the evap -

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These arrived from the Ebay USA guy

post-16906-0-71994200-1404636588.jpg

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