Griffith's AC upgrade for '84 911 install thread

[megerian]

Griff / Charlie / Kuehl - simple questions from an A/C newbie, as I consider the full fix described here versus a lesser approach. The car blows barely cool, never cold. I have recharged once myself using a r134 kit I bought at the store, and I had it once professionally recharged at an auto shop that specializes in German cars, but it didnt last long.

Should I consider just replacing the receiver/drier? What about just the hoses and the R/D? The previous owner told me that he once had a pro try the dye method to look for leaks and none were found, so if I believe him, there were no obvious leaks.

What basic troubleshooting steps would tell me which components need attention?

thanks for all your contributions to this forum

[dentist90]

Agreed (with Bob K). Every time I see the words "trinary switch", "radiant heat" or "fines" I gag, vomit, a bit in my mouth. Seriously.
All we want is our Porsche AC systems to cool to their capacity, whether they be stock or modified. No leaks, cool air in the face. And we come here for advice from those that have been there, done that.
Then WWest chirps in with his tirades, tangents, and begins to derail the focused thought process. OP posts about blower noise and you end up talking about 'entrenched oil' or some such thing. Address the OP's question or don't, but stop using Ac threads as your personal soapbox, platform.

WWest, one question: why have you made it your personal goal, agenda, to trash Keuhl's components? Even his advice? Some of your posts have seriously approached what I would consider libellous. ****

I believe Charlie has assembled, tested and charged HUNDREDS more AC systems on old Porsches than you (or any of us) ever will. He gives sound, practical advice on how to get one's AC cold. Yet you continue to seguey, distract, these threads with useless minutiae. Why can't you resist, control, yourself?

****Not sure if Griff has ever complained to the mods. If not he is a very patient man.

[dos531]

I think he was banned for a little bit and we all breathed a sigh of relief. Seriously EVERY thread related to air conditioning just becomes him arguing his nonsense with everybody else.

He is a joke and we need to find a way to ban him permanently.

Originally Posted by dentist90

Agreed (with Bob K). Every time I see the words "trinary switch", "radiant heat" or "fines" I gag, vomit, a bit in my mouth. Seriously.
All we want is our Porsche AC systems to cool to their capacity, whether they be stock or modified. No leaks, cool air in the face. And we come here for advice from those that have been there, done that.
Then WWest chirps in with his tirades, tangents, and begins to derail the focused thought process. OP posts about blower noise and you end up talking about 'entrenched oil' or some such thing. Address the OP's question or don't, but stop using Ac threads as your personal soapbox, platform.

WWest, one question: why have you made it your personal goal, agenda, to trash Keuhl's components? Even his advice? Some of your posts have seriously approached what I would consider libellous. ****

I believe Charlie has assembled, tested and charged HUNDREDS more AC systems on old Porsches than you (or any of us) ever will. He gives sound, practical advice on how to get one's AC cold. Yet you continue to seguey, distract, these threads with useless minutiae. Why can't you resist, control, yourself?

****Not sure if Griff has ever complained to the mods. If not he is a very patient man.

[tirwin]

Originally Posted by wwest

Digital temperature guage installed/inserted into the rear lid condenser at multiple points, before and after, indicated a substantive temperature rise post engine shutdown.

Don't remember the actual measurements that I posted at the time.

And it isn't simply a matter of "heat soak". Griff's fender mounted condenser is CONSTANTLY affected adversely whenever the catalyst is at operating temperature. The result is that it takes EXTRA air movement(***) to both overcome the radiant effect AND cool the refrigerant.

The same is true of the rear lid condenser but to a lessor effect since the engine does not get nearly that HOT. On the other hand once the engine is shut down and the fan cooling is lost the exhaust heat begins to rise upward to heat the engine and thus the rear lid condenser.

Which is why the 964/993 series, even without the rear lid condenser to be of concern, has a 15 minute cabin heat blower after-run relay/circuit otherwise the fuel within the engine compartment might boil and/or there is the electronic components to consider.

Which is why I wonder if the proper approach, at least initially, is to bypass/discard the rear lid condenser in favor of a rear fender front condenser with a high CFM fan and both front and rear fans controlled via the fan/vane/louver pressure switch section.

*** Quite possibly more air movement than Griff's 70 watt fan is capable of, thereby making it an easy sales job for the second fender well fan.

summary: blah blah blah full of ****

[kuehl]

Originally Posted by megerian

Griff / Charlie / Kuehl

You forgot Chaz.

What you are experiencing is "normal" for a 911/930 owner. Because of the design of the car (rear engine air cooled, aerodynamics of nose, lack of insulation to reduce weight), and the previous marketing philosophies weighted on performance vs. comfort..... the pre 90's models required 40+ feet of refrigerant hose to make connections to all of the components spread out through out the car.
The type of refrigerant hose, called "non-barrier", normal for the time, simply permeates (leaks) xxx parts per million per a given length, of refrigerant over time. The typical non-air cooled front engine vehicle on the road, in comparison, does not have 40+ feet of refrigerant line because most of the components are located in the front of the vehicle, let's say they use less than 10 feet of rubber hose. If you compare the 2 versions of vehicles, the later will leak less refrigerant over time having the same type of rubber hose.

Moving forward, era 1993, with the 'discovery' that R12 refrigerant is not ozone friendly, the automotive industry adopted R134a, which is a bit more ozone friendly. And, the industry adopted a new design of refrigerant hose called "barrier". The Barrier refrigerant hose has an extra liner inside which greatly reduces the permeation or leakage rate. In the context here, our 911's and 930's, replacing the old non barrier hose with barrier hose greatly reduces refrigerant loss. So, if you replace your old and starting to crack original non barrier refrigerant lines with brandy new barrier lines you are going to reduce the leakage rate substantially.
How much? The proof is in the pudding as they say. Ask any 911 or 930 owner who has replaced hoses, and I'm going back probably 18+ years based on our firms client data, or say 1,000+ 911 models.

Other sources of refrigerant leaks and things to do:

1) Evaporator: 1986+ 911 or 930. In that time period they changed the design of the evaporator. Rather than having a copper manifold braze to copper tubes, the decided to bond a copper manifold to aluminum tubes. The design does not hold up well over time, the bond joints leak. Replace that time bomb with something more reliable and more efficient, such as an aluminum serpentine tube design which has fewer brazed joints and has a greater surface area (pulling more heat out of the cockpit as compared to a stock OEM tube design).

2) If you are replacing the hoses you will need to replace the o-rings. O-rings on a 20+ year old car back then primarily nitrile or buna-n. Today they are compounded with HNBR, a more durable and R134a friendly compound.

3) The compressor tends to run at a high temperature in stock system design. Stock, meaning a stock deck lid condenser and front condenser. If you add more condenser area you will lower the compressor temps. We increase condenser area by adding an an additional one in the LH rear fender. This also reduces the amount of heat dumped by the deck lid condenser over the engine; keeping engine temps in check. The original o-ring seals in the compressor, alike the hose o-rings, will fail over time. If your compressor internal parts are in good condition (disassemble the compressor and inspect for wear on the pistons, bores and wobble plate), you'd buy a compressor seal kit; having HNBR compounded o-rings. If the compressor internals are worn you buy an OEM factory Denso compressor alike the model you have. If you see a wet black oil line under the deck lid above the compressor clutch you have a tired nose seal.

4) The receiver-drier has a desiccant in it to absorb moisture that makes its way into the system (25+ years or recharging the system).
Over time the desiccant gets saturated with water and debris. So a new drier, which will typically have a new type desiccant friendly with R134a as well as R12 is in order.

5) System Pressure Hick-ups: most ac systems have a low and high pressure switch that prevents the compressor clutch from engaging if the system pressures get too low or too high. When pressures are too low the compressor will not receive enough flow of refrigerant and refrigerant oil. The compressor relies on this minimum flow to lubricate its moving parts and keep it cool. Should the compressor not have enough refrigerant/oil flow it will break down and you will have metal particles pushed out into the entire system and you will spend a lot of time and money cleaning it up. Adversely, when system pressures get too high the compressor can overheat, break down, blow a nose seal, etc. Other things that can raise system pressures are: over charging, leaving the engine deck lid up too long when the ac system is on and a failed front condenser motor. To help prevent these system hick-ups we typically install a 'binary' pressure switch which serves the same purpose as a separate low and high switch. The binary switch will not allow electrical current to flow to the compressor clutch if the high side system pressure is too low or too high. Its a 'plug in and forget' device that is automatic. We typically incorporate the switch in the compressor outlet hose line as this is close to the compressor and the design requires few adapters which tend to leak over time.

6) Condensers seldom leak. You can get a leak in the engine deck lid condenser if you are not careful using your wrenches to undue or reconnect the refrigerant lines; always use 2 wrenches, one to hold the condenser fitting nut and one to turn the nut on the hose line. You can get a leak in a deck lid condenser if you leave an object on the top of the motor and close the lid. Front condenser: same recommendation with using 2 wrenches, otherwise be careful when driving over rail road tracks, driving up driveway skirts or parking close those 'trip over' cement parking lot front tire stoppers.

7) Refrigerant lines in the LH front fender over the tire can get rubbed and cut. Over sized tires, forgetting to put back tie wraps and hose clamps, not properly aligning the drier.

8) Jack Points and Lifts: there are 2 hose lines that run under the tub (under body) that tend to get crushed when the vehicle is lifted at the lift points just in front of the rear tires. This usually happens as repair shops, where the mechanic is not familiar with the 911/930 lift points, or by DiY's whom are working the car for the first time (read the PP 'how to' section of the forum). By the way, never use the factory supplied side jack to support the car; get yourself a decent floor jack, 4 jack stands and a set of ride up ramps with leading edge rise adapters. SAFETY is always #1 on your list.

Ideally for AC trouble shooting, 'ideally' means you have been around the block, you would need an electronic leak detector and a set of digital gauge service manifold with hoses. That is my ideal because of I have a box of non ideal tools I keep around to show customers why they are not ideal. I do have a fluorescent black light and dye kit but seldom use it because the electronic leak detector is quicker. However, you don't need to spend the money just yet and if you do the tasks correctly in refurbishing your system you won't need the expensive tools again. On the other hand if you like to do things correctly and enjoy friends coming over, or making new friends, showing them how you know how to use these tools, you can buy them.
In the mean time, all you need is a good set of eyes, patience and common sense.
Common sense tells you that you need to replace the hoses, o-rings, drier and add the pressure switch. If you don't have good eyes or the patience then turn the tasks over to an experienced technician. Otherwise you can handle your immediate concerns noted with the logic above. Figure it takes 1 weekend to do the tasks mentioned.

After you have R&R'd the hoses, drier, o-rings, evaporator, and so forth, the system will have to be properly evacuated to remove moisture and ambient gases from the atmosphere. Refrigerant is much like "the character" that will quote and respond to this post, just ignore him. Refrigerant does not like to mix with other characters, such as air and moisture. When it does it does it does not do the job it was intended to do: it will run at higher pressures than normal, cause blockages in the system, cause you confusion in trouble shooting if you are not familiar or experienced with its characteristic presentations. So, having the right equipment (a good vacuum pump and digital gauges; my preference) and experience and knowledge to properly evacuate (pump down the system) the system is crucial (and by the way the most common obstacle for both experienced ac technicians and DiY's).

Next is charging the system which requires the gauges, refrigerant (I prefer using a 30 lb container and weighted charge scale, as opposed to small 12 or 16 oz cans of refrigerant, simply because of my experiences), a knowledge of Pressure and Temperature relationships or charts, and the electronic leak detector (regardless of how detailed you are there can be bad karma on any give day). If you see a repair shop advertising a $89.99 special to charge your system, keep driving, you get what you pay for. Find an air cooled experienced technician; you can identify these chaps in that they might be moving a bit slower because of herniation's at or below C5 (if you see an inversion table in the shop, then you know you have a savvy tech), they can bend down and crawl around because they work on a lot of air cooled's, they are not cheap, etc.

So, the above will give you working AC, but it will be no colder than stock. For that you need more condenser area.

Read The Mr. Ice Project

[techman1]

WW, not to incite your posting again, as others have expressed my own hesitation of reading the AC threads due to your post... But you did not answer my question.

I am not talking about radiant heat or whatever. You claim there is a pressure spike so large, it may cause leaks. Have you EVER verified this pressure spike, on a 911, with gauges hooked up, or is this supposition? It appears all of your posts are supposition, based on your experience in the "Industry". but not a lot of actual experience with the AC system on a 911. Yes or No?

[DaveMcKenz]

Originally Posted by techman1

WW, not to incite your posting again, as others have expressed my own hesitation of reading the AC threads due to your post... But you did not answer my question.

I am not talking about radiant heat or whatever. You claim there is a pressure spike so large, it may cause leaks. Have you EVER verified this pressure spike, on a 911, with gauges hooked up, or is this supposition? It appears all of your posts are supposition, based on your experience in the "Industry". but not a lot of actual experience with the AC system on a 911. Yes or No?

I checked this the last time I charged my system. When I turned off my hot engine the high side pressures dropped very quickly from 225, eventually leveling off around 75-80 psi over 3-4 minutes. No spike was noted. As soon as the compressor stopped turning, the pressure really drops quickly. Your results may vary.
Dave

[megerian]

Griff / Charlie / Kuehl / Chaz

All I can say is wow and thanks, that is probably the most informative single post I have ever read on A/C and gives very good direction and advice for my '88 Porsche.

[kuehl]

Megerian,

Glad we could help you.

On a side note relative to the old geezer making constant derogatory remarks regarding myself, my company, brand, etc. What can I say? We could say he is momo. Or, we could say he ads comedy to the the AC threads.

However, with regard to the Kuehl rearward fender condenser (behind the rear tire). Occasionally the questions arise regarding:

A) Location relative to debris hits: the condenser system is above the angle or projection most objects take, it is above the lower rear fender valance. The tire facing side of the condenser has a solid frame to protect against hard rock hits, and just to play it save there a stone guard that has a dual purpose: A) Its a stone guard, and B) if directs the flow of fresh air outside the fender well to be pulled into the 12" cooling fan, through the condenser and down and out. And, there is a baffle device (flexible mat) on top and below the condenser system that wards off recycling of heated air from the condenser. There is also a debris guard on the high output 12" fan that wards off objects like sticks and there is a 'drop through' outlet on the bottom that allows such things to pass through. The overall design is well thought out and has been in the field since 2001. There are approximately 130 of the first design (tube and fin), and over 600 of the later serpentine design in the field.
The failure rate for debris or rock hits is "zero". The failure rate for mechanical defects is .0068493%. The failure rate for causes relative to improper installation is less than .00041095%.

B) The amount of 'radiant' (direct ray) heat from the cat or primary exhaust system is 'minimal'. Minimal means negligible in terms of performance. A simple performance comparison scenario is an engine tuner trying to squeeze another few percentages out of an engine for a 1 particular race track on a given climate day he sees once a year, however the weather could change any moment; if you have the budget to do so then be my guest. The Condenser is above the direct radiant line of site; meaning very little direct radiant heat contacts the surface of the condenser. We ran tests years ago on the design because it was an obvious thought. We could design and provide a deflector to ward of this minimal radiance however the cost-benefit is not worth the cost, weight and significant DIY work required to wrap the cat with such a device or attach such a device. ..... otherwise we'd include it in the system.

C) With regard to having another Kuehl Condenser in front of the LH rear tire,
this option or choice is all relative to need. If a given car (cabriolet vs. a coupe, or a white car vs. a black car), climate or client needs a particular amount of cooling effect, then its required. For example, a black cabriolet in 90F+ ambient would be prime. An early 911 (1970's) that did not have a dealer installed front condenser.
A 930 turbo having an over sized inter cooler that deletes the deck lid condenser.
And so on. The determination to add xx condensers is typically discussed when our clients provide us data on the car, their climate and personal cooling needs.
We suggest it when it is needed, it's the client's choice to follow our advice.
We recommend that any device (compressor, hoses, drier, ps switch, evaporator and condensers) should all be installed at one time, one shot, do it right and do it once, otherwise you will be spending more time and money changing things down the road.

With regard to Dave M's observation that the system pressure drops when the system is turned off (or when the compressor is not operating) is "normal". There is no device in the vehicle (such as exhaust pipes, engine heat or whatever) which can raise the pressure in the system higher than what a pumping compressor can do. Including a fallacy that heat rising up from the engine after you have parked the car heats up the deck lid condenser and this raises the pressure. And, since the TEV (aka expansion valve) never fully closes (otherwise you low side pressure would be observed to read less than "0") the pressure on the high side of the system (between compressor and TEV) slowly bleeds to the low side, and given an amount of time the low and high side pressure 'equalize' as Dave noted.

[wwest]

Originally Posted by techman1

WW, not to incite your posting again, as others have expressed my own hesitation of reading the AC threads due to your post... But you did not answer my question.

I am not talking about radiant heat or whatever. You claim there is a pressure spike so large, it may cause leaks. Have you EVER verified this pressure spike, on a 911, with gauges hooked up, or is this supposition? It appears all of your posts are supposition, based on your experience in the "Industry". but not a lot of actual experience with the AC system on a 911. Yes or No?

1988 Carrera, HOT day, engine/exhaust/catalyst up to FULL operating temperature, vent airflow as cold as the A/C can produce, meaning the evaporator core is so cold that the TXV is metering the minimum level of refrigerant into the evaporator, the compressor "finishes" a cycle, the thermostatic switch opens due to the evaporator core reaching 30dF (calibrated). R/D sight glass indicates liquid refrigerant

Turn off the ignition... the A/C blower STOPS, as does the front lip condenser blower.

The temperature of the rear lid condenser rose an appreciable amount.

While not an everyday happenstance probably (obviously?) often enough.

Note: The rear lid condenser is under CONSTANT exposure to radiant heat from the engine/exhaust/catalyst which during A/C operation must be MORE than overcome by engine fan cooling.

When the engine stops the radiant heating effects on the rear lid condenser (***) become the dominant factor... INSTANTLY!

*** And the Griffiths fender condenser, if present.

[wwest]

Originally Posted by kuehl

Megerian,

Glad we could help you.

On a side note relative to the old geezer making constant derogatory remarks regarding myself, my company, brand, etc. What can I say? We could say he is momo. Or, we could say he ads comedy to the the AC threads.

However, with regard to the Kuehl rearward fender condenser (behind the rear tire). Occasionally the questions arise regarding:

A) Location relative to debris hits: the condenser system is above the angle or projection most objects take, it is above the lower rear fender valance. The tire facing side of the condenser has a solid frame to protect against hard rock hits, and just to play it save there a stone guard that has a dual purpose: A) Its a stone guard, and B) if directs the flow of fresh air outside the fender well to be pulled into the 12" cooling fan, through the condenser and down and out. And, there is a baffle device (flexible mat) on top and below the condenser system that wards off recycling of heated air from the condenser. There is also a debris guard on the high output 12" fan that wards off objects like sticks and there is a 'drop through' outlet on the bottom that allows such things to pass through. The overall design is well thought out and has been in the field since 2001. There are approximately 130 of the first design (tube and fin), and over 600 of the later serpentine design in the field.
The failure rate for debris or rock hits is "zero". The failure rate for mechanical defects is .0068493%. The failure rate for causes relative to improper installation is less than .00041095%.

B) The amount of 'radiant' (direct ray) heat from the cat or primary exhaust system is 'minimal'. Minimal means negligible in terms of performance. A simple performance comparison scenario is an engine tuner trying to squeeze another few percentages out of an engine for a 1 particular race track on a given climate day he sees once a year, however the weather could change any moment; if you have the budget to do so then be my guest.

The Condenser is above the direct radiant line of site; meaning very little direct radiant heat contacts the surface of the condenser.

Does that mean the Earth isn't in a direct line of sight with the sun? Show me, from what surface on the fender condenser, the catalytic converter cannot be "seen".

We ran tests years ago on the design because it was an obvious thought. We could design and provide a deflector to ward of this minimal radiance however the cost-benefit is not worth the cost, weight and significant DIY work required to wrap the cat with such a device or attach such a device. ..... otherwise we'd include it in the system.

C) With regard to having another Kuehl Condenser in front of the LH rear tire,
this option or choice is all relative to need. If a given car (cabriolet vs. a coupe, or a white car vs. a black car), climate or client needs a particular amount of cooling effect, then its required. For example, a black cabriolet in 90F+ ambient would be prime. An early 911 (1970's) that did not have a dealer installed front condenser.
A 930 turbo having an over sized inter cooler that deletes the deck lid condenser.
And so on. The determination to add xx condensers is typically discussed when our clients provide us data on the car, their climate and personal cooling needs.
We suggest it when it is needed, it's the client's choice to follow our advice.
We recommend that any device (compressor, hoses, drier, ps switch, evaporator and condensers) should all be installed at one time, one shot, do it right and do it once, otherwise you will be spending more time and money changing things down the road.

With regard to Dave M's observation that the system pressure drops when the system is turned off (or when the compressor is not operating) is "normal". There is no device in the vehicle (such as exhaust pipes, engine heat or whatever) which can raise the pressure in the system higher than what a pumping compressor can do. Including a fallacy that heat rising up from the engine after you have parked the car heats up the deck lid condenser and this raises the pressure. And, since the TEV (aka expansion valve) never fully closes (otherwise you low side pressure would be observed to read less than "0") the pressure on the high side of the system (between compressor and TEV) slowly bleeds to the low side, and given an amount of time the low and high side pressure 'equalize' as Dave noted.

And why a heat shield for the rubber hose?

[techman1]

"The temperature of the rear lid condenser rose an appreciable amount."

WW, you coconut head! (All milk, no brains) Answer the question, or shut up. I was not asking about the radiant heat. I asked if you measured the pressure in the system after shutdown on a hot engine.
Yes or No. If yes, did it rise "an appreciable amount"?

[kuehl]

Originally Posted by wwest

1988 Carrera, HOT day, engine/exhaust/catalyst up to FULL operating temperature..... yada ... yada, When the engine stops the radiant heating effects on the rear lid condenser (***) become the dominant factor... INSTANTLY!

No. The the running compressor's pressure creates more pressure than the scenario you describe. You make posts that make you feel you are experienced with AC ....... so put on your gauges and video it for us.

Originally Posted by wwest

Note: The rear lid condenser is under CONSTANT exposure to radiant heat from the engine/exhaust/catalyst which during A/C operation must be MORE than overcome by engine fan cooling.

No.

Originally Posted by wwest

When the engine stops the radiant heating effects on the rear lid condenser (***) become the dominant factor... INSTANTLY!

No.

Originally Posted by wwest

*** And the Griffiths fender condenser, if present is an excellent solution to to improve lower ac vent temps and prolong the system life and you will be happy owning one, or two.

Yes.

[wwest]

Originally Posted by kuehl

No. The the running compressor's pressure creates more pressure than the scenario you describe. You make posts that make you feel you are experienced with AC ....... so put on your gauges and video it for us.



No.



No.



Yes.

Simple, explain why many vehicles of the R-12 era had/have an ~500 HPRV, High Pressure Relief Valve. Many were, are, release to atmosphere, the one in my Ford
Aerostar ported the excessive pressure back into the low side.

Ford shop/repair manual describes the same "happenstance" scenario as I laid out as the likely cause of excessive pressures.

Apparently the inner liner rupture under "EXTREME PRESSURE" as you describe arises from the same happenstance.


Find "extreme pressure"..
Porsche 930 AC Barrier Hoses - Griffiths Technical Inc

[kuehl]

Originally Posted by wwest

Simple, explain why many vehicles of the R-12 era had/have an ~500 HPRV, High Pressure Relief Valve. Many were, are, release to atmosphere, the one in my Ford Aerostar ported the excessive pressure back into the low side.

First, this thread, the one you have been characteristically hi jacking, is about the installation and upgrades of an ac system in a 911. It is not about your Ford, nor about you.

Second, the old style, now illegal, blow off valve has nothing to do with any scenario you are trying to sell.

Third, "EXTREME PRESSURE" you are taking out of context, and the context on our barrier hose page reads like this....."barrier hoses....... The small holes allow pressure to escape in the event that the primary inner wall of the hose should fail under extreme pressure. The designers contemplated that it would be better to avoid a sudden eruption in the outer wall that could harm the vehicle or a technician working on the car. Under normal peak operating pressures refrigerant does NOT leak through these holes. Sorry, I can't see any play or flip where you can use the context or the discussion regarding barrier hoses under 'extreme pressure" to where ever you are going with whatever you trying to communicate.
Although I enjoy the SEO boost your rants give, you are pissing on your leg in every post and its starting to stink terribly.

Its a sad shame, your stomping over every ac thread with the same nonsense over and over again. Here, a chap is trying to help out fellow forum members with a rather detailed AC install and overall and you are so selfish, so childish. Seriously, find another avenue to play with your weak ego.

At this juncture you are dropping the rankings of PP in terms of valuable information for Porsche owners. I'd boot your butt out of here toot sweet if I could find the eject button.

[wwest]

Originally Posted by kuehl

First, this thread, the one you have been characteristically hi jacking, is about the installation and upgrades of an ac system in a 911. It is not about your Ford, nor about you.

Second, the old style, now illegal, blow off valve has nothing to do with any scenario
you are trying to sell.

"nothing to do.." Only for a fully closed mind such as yours, even an idiot can see the parallel.

Third, "EXTREME PRESSURE" you are taking out of context, and the context on our barrier hose page reads like this....."barrier hoses....... The small holes allow pressure to escape in the event that the primary inner wall of the hose should fail under extreme pressure. The designers contemplated that it would be better to avoid a sudden eruption in the outer wall that could harm the vehicle or a technician working on the car. Under normal peak operating pressures refrigerant does NOT leak through these holes. Sorry, I can't see any play or flip where you can use the context or the discussion regarding barrier hoses under 'extreme pressure" to where ever you are going with whatever you trying to communicate.
Although I enjoy the SEO boost your rants give, you are pissing on your leg in every post and its starting to stink terribly.

Its a sad shame, your stomping over every ac thread with the same nonsense over and over again. Here, a chap is trying to help out fellow forum members with a rather detailed AC install and overall and you are so selfish, so childish. Seriously, find another avenue to play with your weak ego.

At this juncture you are dropping the rankings of PP in terms of valuable information for Porsche owners. I'd boot your butt out of here toot sweet if I could find the eject button.

So, illegal or no, many remain in use. But, of what purpose was/is the HPRV, or even the barrier hose leak capability in case an EXTREME PRESSURE event ruptures the inner liner.

Both designs, clearly, had a reason for being incorporated in A/C systems.

So, why isn't my scenario just good as one you might invent.

[Bob Kontak]

Originally Posted by wwest

So, illegal or no, many remain in use. But, of what purpose was/is the HPRV, or even the barrier hose leak capability in case an EXTREME PRESSURE event ruptures the inner liner.

You said you have to post in this specific thread to "Keep It Simple Stupid"

You are a liar and inconsiderate.

The last two times you were banned I provided a warning to you that I was contacting the administrators. I contacted them. You were banned.

This time I will facilitate your permanent ouster.

Do you want me to give that one a whirl or do you want to back off a bit with the thread disruption?

Your choice.

[Ronnie's.930]

Originally Posted by Bob Kontak

Do you want me to give that one a whirl or do you want to back off a bit with the thread disruption?

Your choice.

[SilberUrS6]

Originally Posted by Ronnie's.930

^this. I am so gawd-damned tired of wwest's continued bullschitt that I have started reporting every post he makes in these threads. I fully encourage all of you, who want these threads free of this off-topic and tangential (and mostly imaginary) bullschitt.

Look, fellas, I'm a guy who loves a great workaround as much as the next guy. Fred Cook's fuse panel? Genius. Griff's brute force solution to high heat and humidity of the SW/SE U.S. You're darn tootin'. But, since this is a tech forum, I gonna get all sciency and stuff. Let's talk about heat transfer, shall we? When we talk about heat transfer, there are three major ways (and the minor ones don't apply, willard, so shut your fscking mouth for a change). There is conduction, convection and radiation. Conduction and convection are mass-transfer methods of heat transfer. Ever make tea and leave your spoon in the mug? Didja notice how hot the spoon was after a while? That's conduction. Direct mass transfer of heat from one medium to another via contact. OK, how about fire? Have you ever noticed that the flames go up, and not in every direction? That's because the molecules of burning stuff and air and non-burned stuff have less mass per unit volume than the surroundings. Nothing is moving here except the air and the vaporized stuff that is combusting. You are viewing convection in action. Radiation. Radiation is the passive heating of something from a source, via electromagnetic waves. It is a cube root function, and that means that the further away from something hot you are, the heat you feel diminishes by some number over the distance to the third power. The fact that you can feel comfortable with the sun on your face is a testament to how damn far away this thermonuclear reaction is. Continued...

[SilberUrS6]

So, when we're talking about AC, everything is about mass transfer. I say that because of a simple rule called black body emissivity. This is how well an object either absorbs or radiates electromagnetic energy. For a perfect black body, the number is 1.0. Humans are about 0.97 on the emissivity scale. Aluminum is 0.10. You know, that stuff that condensers are made of? Stainless steel (cat housing material) has an emissivity of of 0.85 for weathered material. And it varies depending on material type, of course. This means that at the distance from the cat to the condenser, the radiant heat is so small that you could put your hand right next to the condenser and never feel uncomfortable. There is more contribution to system heat soak from the engine heat at shutdown, that's how small an effect radiant heat has. Of course, all of this information is a Google search away. I spent five whole minutes looking up the particulars. OK, so what is the major way that condensers work? Mass transfer, by conduction. The air touches the aluminum, and picks up heat energy. When the fans and compressor aren't running, convection rules inside the system, and conduction outside, but driven by convection. (Instead of by a fan.) This is why when a fan is on low, the air out of the vents feels colder. Because it is. The air has more time to be in contact with the evaporator, so for each unit volume of air, the evaporator transfers more heat.

Look folks, this is all science. Freshman physics kind of stuff. And by that, I mean freshman in high school. The emissivity and distance from a radiative emitter is freshman in college. Add to that the practical working knowledge of a guy who has sold hundreds (thousands) of AC parts to 911 people, and you can try and make up your mind who is telling the truth, and who is a fscking liar. All of this posting of fact will NOT chase wwest away, as it would anyone who had a lick of sense on how badly he's been whacked in the nutz. Which is why each of you, every time wwest posts, has to report him as a troll, or as spam. Only by volume of voices will he every get the permanent hook here.