The problem with the balloon test is that it doesn't represent reality.
Because the balloon has another hole in it so it won't hold air.. The txv. See how your thinking is so flawed.

It's not the technical issues, it's the attitude.

I reviewed the 2011 post where our resident junkie did in fact use the term superheat. I am sorry wwest for assuming you only heard about superheat today. I was WRONG.

However, in that post I picked up that the odd and alienating communication style was present as today. Statements Kuehl made were distorted and spun in a manner to discredit him. I understood what Kuehl was saying and it made sense. Nothing earth shattering, just pretty basic stuff but there was a definitive focus to discredit Kuehl regardless of what he wrote.

What is up with that? What am I missing?

That is what I keep asking... He won't answer.

There are plenty of others selling the same goods. Yet never a mention. There are valid arguments made for many of the solutions and yet its all snake oil.
It's very perplexing. Why would some one care so much.
Half the "upgrades" people buy are marginal. I have a few myself. But this is a hobby for me. I enjoy locking myself in the garage and wrenching.
Whether its a ac kit, a new interior, some fancy suspension parts def not needed on a street car...
No one says... Hey you're an idiot for putting poly bronze on a street car. Or your stupid for doing aftermarket efi. Some may think its stupid but its my money and they respect that.
Yet wwest seemingly spends 12 hours a day just looking for ways to slam griff.
It actually hurts his credibility rather than help it.
I think wwest makes some valid points. Half my ac parts aren't even griffiths. Yet if I disagree with him I'm a Khehl shill.
Very weird behavior.

I don't get that. Kick the crap out of John Walker, then. He has a shop. Porsche962 and Freddie Hernandez have paint shops and post in the bodywork forum. They are easy targets, too. They are all ****ing shiesters, right?

Perhaps not gaining acceptance from Griffith's Tech on the engine heat theory is the issue.

wwest? Comment please. It's fair to ask.

What the f*** did you do to your car, Aryton?

OMFG - let's just start calling you Captain Zurk, cause that's where you are going to be - on your effing back - greasing up them noisy ass squeakers.

Brove you, man!

He doesn't have the balls to be honest...

Lol so true. But I'm already laying on my back doing a valve adjustment so all in a days work...

You implied that a raise in temperature did not necessarily result in a rise in pressure. Blow up a balloon, heat the air/gas inside and the balloon expands.

Why?

The gas inside rises in volume when heated. Restrict the gas to a ridgidly fixed volume and the pressure increases.

Okay, now think about the '94 Ford system that has a 250 PSI pressure relief valve on the SUCTION side, YES, the SUCTION side! In order for that to happen the high side pressure must have been equalized with the low side but HOT enough to raise the total volume pressure to 250 PSI.

Now think about what that might mean for our systems.

My thinking is only flawed provided the TXV doesn't fully close. Now we're awaiting Kuehl's admission that it does...

Just look at the myriad of automotive applications wherein this same TXV is used but do not have the extraordinary suction side volume. It would be senseless for an engineer to design into one of these systems a TXV that is destined to destroy compressors.

Speaking of Kuehl, a question...

Assuming you are correct and the factory TXV did not fully close, what would be the pro and con of replacing the factory TXV with a TXV that does fully close when the superheat crietria dictates such action.

Even if the balloon didn't have a second hole in it, the thinking is still flawed.

More than half of the high side volume of the system (balloon) is not in the engine compartment. The receiver/drier, front condenser and at least 25 feet or more of hose.

I guess one could always video tape this hot engine effect and post the results right here.
If anyone has a good R-12 Thermostatic Expansion Valve that was removed due to a refrigerant swap. Send it to me and I will bench test it and post the results.

Okay, a bit of speculation, logic based, but speculation.

I have found several sources that indicate the evaporator temperature compressor clutch control's shutoff level is 26F +/- 2F. Other sources indicate that with the system operating correctly the "float ball" in the sight glass should indicate the R/D being "full" of liquid refrigerant with the compressor clutch engaged.

Assuming these sources are correct how is it that the R/D can "fill" before the evaporator core temperature declines to 26F....

The speculation part:

In order for the R/D to fill with liquid refrigerant there must be a serious downstream blockage to flow thereby making it difficult for the evaporator core to decline to 26F...

That suggests that at 26F the TXV must be very tightly closed in order for the R/D to "fill" before the compressor clutch disengages...

Even if the TXV not fully closed, only mostly so, starting "our" test with the R/D's full "fill" of liquid refrigerant and the evaporator already at ~28F, and with cabin air movement null, how long might it take for full equalization...?

Wouldn't the level of liquid refrigerant in the R/D serve as "blockage" to high side pressure relief, GAS pressure relief, until it is discharged..?

http://forums.pelicanparts.com/porsche-911-technical-forum/224667-interpreting-sight-glass.html#post1954374

"...the pale yellow ball FLOATS in the freon, even when the A/C is off...."

June, 2005, Houston, TEXAS...

Wonder just how long that ball floated after the A/C was switched off....??

Since you are speculating - that means two or more parties will be engaged if a discussion is to take place - may WE utilize the standard communication model?

When I start my car cold (out of the sun) I feel cold air right away. A few seconds longer if in the sun and fully baked. Wimpy cold at first but starts kicking in pretty good after five or so seconds.

If I get cold air directly, I would not think that means that the orifice closes to fill the R/D.

Mine does not float when turned off but I never watched it drop. I have R12.

Are you thinking this may be a test of equalization speed?

http://forums.pelicanparts.com/porsche-911-technical-forum/304231-let-ac-fun-begin-oh-blow-45-a-6.html#post3845058


Kuehl: thoughts?

The TXV does not "close" until the evaporator core declines to <30F, that does not happen quickly, less so on a hot day/start. So the "reservoir" will not begin to fill until the compressor output exceeds the metering rate of the TXV.

If the overall heat load is high enough the TXV will remain open, "consuming" refrigerant as fast as it can be supplied by the compressor and condensor cooling capability.

Why the question of wondering how long the ball floated after shutoff?

THe ball floating for an extended period would mean the TXV remained closed, or mostly so, for the extended period.

The R/D is the "last stop" for the liquid refrigerant prior to being ported into the evaporator via the TXV apperture. If the level remains fairly stable even with the A/C off then the TXV must be metering the refrigerant very slowly, if at all.

Or as Kuehl says elsewhere, continuously cycling between fully closed and only slightly open.

With the TXV fully closed the evaporator core will "warm", quite slowly since the blower has stopped. Once it warms enough the TXV will slowly open ever so slightly, porting refrigerant into the evaporator, thus "rechilling" it to the point that the TXV closes yet again.

That "cycle" will continue until the entire contents of the R/D have been exhausted.

Dang!.....All I wanted was an adapter! Not a story!

Or pressure equalizes?

That write up makes sense to me.

I ain't saying it's right because I don't fully understand the whole dynamic. But I do understand that it bleeds out and flow will be restricted when the evap gets chilled.

I say we dig up a valve and send it to billybek.

An OEM part is $35 and a cheaper one is $13. Chripes, I'll buy the cheap one just to put this to bed.

Also, Kuehl said it. I read it. Who can believe a 3rd tier AC tech anyways?