Another A/C question

garmo · 07-23-2003, 06:09 AM

Hi Guys,

I have a 1908 SC that was burned up in a fire several years ago. I bought her after the fire and am getting closer to finishing it.

I have not put the A/C bank in yet. I have heard that the a/c on 911s is typically poor. I have no personal experience with 911 a/c so I am wondering if this is true. I saw te earlier post about the a/c being too cold.

What, if any, mods are you guys doing to make your a/c blow cool/cold air? I do not have any a/c tools and do not even know how to check the compressor to see if it is good. Can anyone explain how to do so?

Thanks for you input.

smoak · smoak's Garage

Porsche pre-993 = crappy air conditioning. Do a search for the AC projects out there. There are some recently discussed threads that have a lot of helpful information that I have found.

targa80 · targa80's Garage

The 1980SC has the not so good York compressor. If you are planning on redoing the AC I would suggest upgrading to the newer rotary type compressors. There are threads on this board of some pretty good mods that can be done.

scottb · 07-23-2003, 06:44 AM

Install barrier hoses, and a new Sanden compressor, at the very least. Consider putting a fan/condenser unit in the front left fender. Don't waste your time with the York compressor. Vertex sells a compressor/bracket kit that will work on your car.

William Miller · 07-23-2003, 07:06 AM

My 83 SC has a small condensor above the motor and a second mounted in the left rear fender well. It has a electric fan, like I've seen used on an oil cooler. This seems like a dumb location since it's right next to the Cat and the muffler.
The evaporator is in the normal place.
I have a rotary compressor.
Scott mentioned a condenser mounted in the left front fender. Is this in front of or behind the tire? I have my washer bottle in front of the tire.
Is this one of 2 condensors or the only condenser?
How are the hoses routed.
I currently have my engine out to rebuild it and am thinking about my options. I herd of several ways AC was installed in an SC what is the best system?

scottb · 07-23-2003, 08:45 AM

William: There's a split of opinion on the rear left fenderwell condenser. Some say it works great, others, like you, are concerned about its proximity to the exhaust system.

I'm currently installing a fan and condenser in the front left fenderwell, in front of the tire. I'm removing the washer bottle and vapor recovery tank. The washer bottle will be replaced with a generic one installed in the luggage compartment. The vapor recovery tank will be replaced with a small steel "catch can." I'm not sure where the "catch can" will be located as of yet.

When all is said and done, I'll have three condesners -- the two original condensers from the factory, and the third one in the fenderwell.

William Miller · 07-23-2003, 12:59 PM

The PO never told me how well it worked. The small condenser (doesn't cover the air intake grill) has some fins crushed and a probable hole from rubbing the coil. One of the hoses from that small condenser has a hole almost rubbed thru it. (From the edge of the lid.) The fan on the condenser in the rear fender is rusted pretty bad.

I'm assuming this is probably an aftermarket system so I don't know where to find parts.

Keep us posted on your project:
The more condenser surface area = more heat lost!
I guess you'll answer the question if the condenser(s) is/are the weak link. Will you keep the standard evaporator?

scottb · 07-23-2003, 01:11 PM

I presently have no plans to replace the evaporator. I'm open to being convinced otherwise, however.

david914 · 07-23-2003, 02:43 PM

I'm curious as to how much improvement can be made on the stock evaporator. The Griffiths unit looks nice and it touted as being better, but by how much? (and for how $$$ much?) I've got my stock unit out of the car right now. I've cleaned it and am in the process of deciding on how to re-seal it so that air passes through it and not around it. The factory "weatherstripping" around the core was completely desintegrated and the bottom (intake side) of the core was clogged up with debris. I'm sure it will work much better just from getting a good going over.

Adman · 07-23-2003, 02:58 PM

Quote:

Originally posted by david914
I'm curious as to how much improvement can be made on the stock evaporator. The Griffiths unit looks nice and it touted as being better, but by how much? (and for how $$$ much?) I've got my stock unit out of the car right now. I've cleaned it and am in the process of deciding on how to re-seal it so that air passes through it and not around it. The factory "weatherstripping" around the core was completely desintegrated and the bottom (intake side) of the core was clogged up with debris. I'm sure it will work much better just from getting a good going over.

David...I used the closed cell foam camper top weatherstripping they sell at Home Depot. Others on the forum had used it successfully. All of the gasketing had desintergrated also.
Matthew

david914 · 07-23-2003, 03:29 PM

That's good to know. That particular foam is the only thing I could find that was thick enough to bridge the gap between the evaporator core and the housing. I'm assuming that a friction fit is adequate since that particular foam doesn't have any adhesive. My neighbor suggested trying some canned foam, but as well as that would seal, it would be a bit too "permanent".

Adman · 07-23-2003, 04:21 PM

Quote:

Originally posted by david914
I'm assuming that a friction fit is adequate since that particular foam doesn't have any adhesive.

Hmmmm...I thought I recalled it having adhesive on one side. Guess not. I did use a double thickness in a couple of areas to tighten the friction fit.
Matthew

scottb · 07-23-2003, 05:00 PM

I had my evaporator box open last year, and cleaned out all the gunk and resealed it. I used Griffith's kit for the job. He has a sheet of thin plastic that he uses to seal the evaporator. It sits down near the bottom of the box, and has a cut-out in it in which the evaporator sits. The seal is not very tight, however.

David, I'd be interested to see pictures of how you re-seal your evaporator. I'm going to have my evaporator box open soon to re-route the hoses to install a ProCooler, and I'll easily be able to add some sort of insulation if it's necessary.

I recently exchanged e-mails with Charlie Griffiths on the subject of his new-and-improved evaporator. My sense is that it will result in some improvement, but not a significant amount. For the time being, I'm not going to make a change (unless anyone here convinces me otherwise).

nhromyak · nhromyak's Garage

Which refrigerant are you planning on running?

R12 = expensive - you should replace non-barrier hoses.
R134 = not so expensive, but you don't need to replace non-barrier hoses.

Definately get a later model rotary compressor.

Parallel flow condensors appear to be a cheap/good mod.
The one in the rear deck can be had for just over $100. (if you need it).

Griffiths new modified Evaporator = $400+

There new modified compressor is $599 w/ clutch. Only $424 (R134a) without (if I am reading my notes correctly).

You will NEED a new drier no matter what you do... ~$40 - $80
You MAY need a TXV (expansion valve) I have seen these as low as $24!
Or the TXV may simply need to have it's filter cleaned.

Good luck.

William Miller · 07-25-2003, 05:56 AM

ADMAN, Is the foam you are taling about simular to that on a pool noodle the kids use?

If so they make a construction product called a backer rod. It is used to fill large voids before they are caluked. They were used as part of a dryvit system on a shopping center we have. At the bottom of the dryvit there is a brick ledge. The drivit stopps short of the brick to allow for expansion. The wide joint is filled with the backer rod and caulked on the face that you see. The rod saves a lot of caulking. I've seen it in different thicknesses up to 3/4" diameter. Yep, it's round like a noodle.

If this is the same kind of foam it might be perfect.

RickM · RickM's Garage

I think the Drier is about $17 from ACKits.com.