Installing AC

gorfllub · 05-15-2005, 02:42 PM

Hi Y'all

I bought my 83 SC, but at some point in its life, someone removed the majority of the A/C.

The lines are there, the controls in the console, and the evaporator. (Unit in the smuggler box)

Anyhow, I bought a complete A/C setup from a fellow Pelicanite. I will be attempting to install such parts in the near future.

I have a couple of questions though. I have read many posts here about bad (Not cold) a/c here. The best I can tell, this is attributed to not enough cooling/airflow for the condensors? (Correct me if I am wrong)

What is the best way to alleviate this without buying a griffiths kit? I am putting on a wide-body (really Fat!) 993 kit around the same time. I will have lots of room in all the fenders/quarters.
Should I increase condenser area, or would it be just as effective to increase airflow across the condensors I already have. (With the new body kit, I could quite easily do a front mount condensor AND front mount oil cooler. (I could also add electric fans, as I have access at a low price)

I assume, If I do add more condensor(s) they just simply get put inline?

Also, I assume I should have the old gear tested and cleaned prior to installation.

Any other tips or tricks? I hear a lot of guys doing propane in the system. It sounds like it works fine (Well, ok Better than fine) but I think I am going to convert and run the proper refrigerant.

Thanks in advance. I must say that this forum has taken away almost all of my worries as a first-time P-car owner. I have learned a lot here and made some new friends. Its definately great!

Thanks
Jeremy

Hladun · 05-15-2005, 03:02 PM

Airflow through the condenser is very important. I built a system for my 78SC using only the decklid condenser and a pancake fan from JC Whitney and the system works well. If you don't use a condenser fan no amount of condenser area is going to help when you're stopped. If you want more details do a search on my previous posts.

Hugh R · 05-15-2005, 03:02 PM

Do a search on Jim Sims name and you'll find out everything you'd want to know about A/C/. Convert to R134a, its relatively cheap and according to Jim, propane doesn't carry the refrigerant oil well, and will lead to a burned out compressor. Yes, you add more condensors inline with additional hoses. Here's a trick, buy the hoses and fittings but don't crimp them, fit them to the car, remove and have crimped. If using 90 degree fittings this is especially important as you can't twist those hoses at all. Mark the position with a Sharpie type marker where you want the crimp done. Crimping charges are separate from the cost of hoses and fittings, so there is no cost savings or extra expense.

da911enginear · 05-16-2005, 08:15 PM

I think for your 83sc, since you have wide fenders I would go with many condensers. I saw a Griffiths Kuehl system in an 85. It had 4 condensers! The stock engine lid one, the one behind the rear tire and the one in front of the rear tire and the one that is normall y in the front. In FL it gets hot and humid and this car was blowing real cold. The condensors in the fenders looked like factory installed units. I've been reading the threads and thinking about building my own but after seeing all the hack jobs I'm pondering.

bigchillcar · bigchillcar's Garage

with just the decklid condenser on my car, and with a regular lid (now wing, duck, etc.)..where would i mount an electric fan when i have a cis car? i suppose it would have to be below the condenser and pullling air through..anyone done this?
ryan

da911enginear · 05-17-2005, 05:05 AM

Looking around at this stuff I did see a setup where this guy
put two small fans on the underside of the deck lid condenser.
The fans were puller fans sucking air downward. But since they were so small it was not getting enough cfm flow, and once the engine cooling fan reaches xxxx rpms it has more power than the two small fans so they don't work when that point is reached. I guess it might be a little helpful when you are idling, but once your engine gets up to speed they are simply just in the way of air movement across the coil.

Hladun · 05-17-2005, 05:57 AM

Here's the theory;

'74 911 a/c upgrade

And it works.

My car doesn't have the air pump and I cut back the air cleaner horn so I have space for the fan.

bigchillcar · bigchillcar's Garage

excellent thread hladun,
i'm thinking your fan mod (is it pulling air through from outside or pushing from below?) and a procooler combo would be more than enough for my humid arkansas summers. jim sims has also posted info about some sort of heat exchanger device which he has shown mounted near the steering gearbox wrapped in heat foil..don't know how well it works..thanks for the great info.
ryan

jdowty3 · jdowty3's Garage

Have the evaporator and any condensors flushed before installing, replace the lines if they are not barrier style hoses and buy a new expansion valve and drier unit. Also, have the compressor checked and the schrader valves replaced. Also check the other ac thread going on right now about the Rennaire procooler.

Hladun · 05-17-2005, 09:26 AM

Quote:

Originally posted by bigchillcar
excellent thread hladun,
i'm thinking your fan mod (is it pulling air through from outside or pushing from below?) and a procooler combo would be more than enough for my humid arkansas summers. jim sims has also posted info about some sort of heat exchanger device which he has shown mounted near the steering gearbox wrapped in heat foil..don't know how well it works..thanks for the great info.
ryan

The fan blows out and thereby effectively doubles the flow through the condenser.

tcar · 05-17-2005, 12:22 PM

So, I've looked at your numbers... it doesn't hurt engine cooling? Seems like it would; create a low pressure area at the engine fan.

Why wouldn't it?

Hladun · 05-17-2005, 12:33 PM

Quote:

Originally posted by tcar
So, I've looked at your numbers... it doesn't hurt engine cooling? Seems like it would; create a low pressure area at the engine fan.

Why wouldn't it?

It's a case of pressure drops (Bernoulli's Law). The drop in pressure is so negligible as to be of no effect. Other factors such as dirt on the engine, levels of internal engine friction, oil grade, humidity, fan condition, air leakage, and elevation are probably comparable.

patkeefe · 05-17-2005, 12:39 PM

Propane ( I may have this confused with isobutane) has the same thermodynamic properties as R-12. The only difference is, it's flammable.

Statistically, most of the ozone depletion is caused by chloroflourocarbons, such as refrigerants. The biggest leakers of refrigerants are....automobiles! The rubber hoses all leak!

Reviewing this, I would recommend that anyone using propane or one of the other "drop in" i.e. hydrocarbon refrigerants bought at Pep Boys also purchase a good fire extinguisher.

Pat