Liquid R-134a going forward!

[Jim Sims]

We had a 2nd 911 A/C tech session last Saturday and I finally got around to pumping down and filling the resurrected A/C system on my '76. After locating a leak (flare fitting joint at expansion valve) and replacing a defective high pressure fitting Schraeder valve on the compressor we did the deed. We also converted a Turbo stock system over to R-134a and boosted the fill and added some compressor oil to a Carrera that had already been converted. In the '76 we obtained 50 F vent temp idling in driveway and "putting" around town at 30 mph with 90 F ambient air temp and full sun load. Out at crusing speed (~75 mph) it will freeze one out; I had to increase the temp and turn down the blower. 90 F ambient, ~3-4% grade, 3-4K rpm, 60-65 mph with A/C on full, oil temperature rose to 210 F and stabilized with trombone cooler. Engine has 11 blade fan, new Sanden compressor, NOS engine deck lid condenser, new barrier hoses, new receiver/drier from NAPA, new expansion valve, flushed and cleaned evaporator, better sealing of original blower and I added a 88 CFM muffin fan (12v and .45 amp for $6) behind passenger footwell floorboard to boost air flow across evaporator. Filled the system with ~24 oz. of R-134a; monitered pressures while filling and used a small 110 VAC window box fan to blow air over condenser to obtain better high side pressures while filling. Also have a 300 CFM muffin fan (12v and 2.45 amps for $19.00) to mount on the decklid condenser; there is just enough space to squeeze it in. I will either relay it to come on with the compressor clutch or add a temperature switch on the condenser. Took some digital pictures; I'll try and get them uploaded. Making 911 popcicles in Los Alamos Jim

[scottb]

Jim:

I'm also doing an a/c upgrade, and I'm adding a front fenderwell condenser with a fan across it.

I'm intrigued by the notion of the fan in the footwell. Can you tell us more about it? How big is it? How did you mount it, etc.? Please post pictures when you can!

Sounds like you did a great job! Congrats.

[Jim Sims]

12 v .45 amp 4-11/16" square by 1" thick 88 CFM muffin fan Sanyo 109P1212H402; $5.95 (plus shipping) from Marlin P. Jones & Assoc. www.mpja.com (thanks to Early S-man for the source).





Installed muffin fan from passenger side footwell; note that return air to the evaporator in smugglers only had six hole saw holes to pass through. I connected the tangents of the four larger holes leaving tabs to mount muffin fan. Lack of return air cross-section is a problem with some of the "dealer installed" A/C systems.




View of muffin booster fan for return air from inside empty smuggler's box before evaporater/blower unit is reinstalled. The muffin fan is wired into the compressor clutch circuit. It comes on whenever the thermostat switch (temperature switch) turns on the compressor.


This afternoon the car (parked with sunshade in windshield) dropped from 115F duct temp to 60F duct temp in 5 minutes driving at 35 to 45 mph with about 90F ambient, full sun load and driver.

More later, Jim

[scottb]

What was there before the "surgery?"

[Jim Sims]

View of engine with new A/C system installed. Griffith's kit no.1 , NOS evaporator and new barrier hoses with bead lock fittings I made myself. Note over pressure compressor clutch cutout switch on high pressure line near oil filter.




Checking for leaks and evacuating the system with my friends "Yellow Jacket" vacuum pump and R-134a refrigeration gage set (thanks Dave!). Later during system charging with R-134a the engine hatch was closed.



More later, Jim

[scottb]

Jim: No pictures?

[Jim Sims]

[Jim Sims]

[magilla]

This looks great! I have never cared about A/C in my SC, but I guess if it worked, I would use it. Forgive my social faux pas, but how much does this kind of cooling performance cost (parts & labor)?

[RickM]

Jim,
Thanks for the info and pics. I'll keep this thread for future reference.

[Jim Sims]

Before I connected the holes to the smuggler's box there was a pattern of four 2-1/2 inch diameter hole saw holes and the two smaller holes which the wires pass through. These holes were made during the original "dealer" installation in 1976. All of this (including the muffin fan) is hidden behind the passenger floor board.

I have roughly $1100 in parts and supplies invested; this amount could be reduced by about $550 if one was willing to make more parts and fittings oneself and if the existing condensers are in good condition. I ordered barrier hose and fittings on-line and made the hoses myself. I purchased a new ATCO bubble crimp tool kit for beadlock A/C fittings on E-bay for $225 (new retail cost ~$500). It was very convenient to run the hose and then put the fittings on in-situ (the ATCO crimp tool permits this). I have approximately 30 hours of my own labor invested but I'm not very efficient (it's a hobby and I take my time and enjoy the experience).

To avoid the hot oil cooler lines I also rerouted the refrigerant hoses to run forward along the driver's side rocker panel and then cross over just behind the steering rack to the passenger side to enter the smuggler's box from the front passenger side wheel well. The hoses are well secured and show less than oil cooler lines; in fact to see them one has to get way back or peer under the car.

Cheers, Jim

[derkpitt]

Are you concern that the muffin fan mitt just blow the air right out threw the driver's side inlet?
Instead of threw the evap.

[Jim Sims]

The muffin fan is directly in front of the lower part of the evaporator and the evaporator is encased within a plastic housing from which the main blower draws the cooled air. There is indeed the possibility of some leakage to the side of the muffin fan but I note that with it running alone (without the main blower turned on) that there is air being forced through the A/C distribution ducts under the dash. Cheers, Jim

[gt3r]

Hey Jim, I'm about to redo my lines in my 85 and have been looking for an atco crimper on e-bay but I haven't seen one lately. Are you going to sell or would you rent the crimper out?? Aslo where did you source the fittings and hose from?? Thanks Mike

[plain fan]

Jim,
Do you think you could post some pictures with the evaporator housing(box) installed? I'm looking for pictures with the driver side return hooked up, mine is missing.
Thanks

[emcon5]

Originally posted by Jim Sims
new receiver/drier from NAPA,

Can you elaborate on this? Is this a generic piece, or does it bolt right up?

Tom

[Jim Sims]

gt3r,

I'm going to keep the ATCO crimping tool and I'm not really interested in renting it out as I will using it through the summer (it's one of my contributions to our 911 group here in the Santa Fe/ Los Alamos area). Due to the heat, there's always an interest in getting a 911 A/C working and the R134a conversions seem to be doing okay and I expect we'll be doing more of them as the summer progresses and again next summer. The company in Dallas I bought the crimper from had several; I'll see if I can locate their address/phone number and post it. The hoses and fittings came from www.automotiveacparts.com They sell #6, #8 and #10 barrier hose in 12', 25' and 50' lengths plus typical fittings (barb, beadlock, o-ring, flare, etc.). I also purchased a new expansion valve from them. Prices were very good and service was good. When making new hoses I recommend one convert to o-ring type fittings where ever feasible (compressor and receiver/drier) as they are much less leak prone. Of course to retain an existing condenser and evaporator one has to put flare fittings on their mating hose ends.

plain fan,

My unit doesn't have a return from the driver's side nor from the tunnel. The nozzle from the tunnel is sealed with a rubber cap before the evaporator/blower is installed. In my '76, with my kit; return air is pulled behind the passenger side floor board and then into the evaporator. There is a gap on both sides and the top of the floor board to allow air to enter.

emcon5,

The NAPA receiver/drier is somewhat generic but can be made to fit if one is willing to flip a hose around, install a bigger hose clamp to secure the r/d and unscrew the installed pressure switch and replace it with a plug made from a 3/8"-24UNF hex head cap screw. It also come with adapter fittings which allow it to be used with flare or o-ring type hose fittings. The NAPA unit readily replaced my recevier/drier since the system came originally with a similar diameter unit made by Modine. I have yet to find the longer but smaller diameter German OEM Behr receiver/drier for less than about $90. If one has big tires and/or a power antenna one may need to stay with the Behr type unit. I have posted the NAPA part numbers in a previous thread:

Source for AC parts?

I have more images of the evaporator/blower unit and the receiver/drier and right front fender hose run; I'll post them when I have some more time.

Jim

[Bob's Flat-Six]

Jim,
Thanks for the info.
I just got the A/C up and running on my SC with a pretty much stock system and it's doing very good. I got 32 deg. temp's at the vents but it didn't want to maintain it on a 90+ degree day and went up into the low 40's.
I think your hitting the nail on the head with the added fan's though. The fan in my smugglers box was tired and starting to make noise and once replaced with a new unit it made a big improvement by just blowing more air.
I added the khuel vent to make better use of the bow tie vent air flow and that was a big help. It's pricey but a good fit that installs easy and looks factory. And to me for the 150/ shipped a cheap improvement to get better working a/c.
They put freeze 12 in my system as it's hoses are original. The York compressor was replaced with a Sanden, another big improvement.

I am curious about a fan on the rear condensor as I've heard that mentioned before.
Keep cool

[930slant]

I installed a fan on the rear deck condener and it has helped. I went through several stages of upgrades fron the original non-barrier hoses/r-12 system that rarely got temps below 60 on a 90 degree+ day. i was talked in to converting to 134 and although it was cheaper in 1999 to recharge, the cooling suffered. I went back to r-12, installed the pro cooler and barrier hoses. Temps got into the mid to low 50's. Last year I got the evaporator/expansion valve and bow tie from Charlie G. and the deck lid fan from Performance Aire. (I only have 1/2 the condenser in the deck lid since my car is a 930.) The bow tie really aids in the air movement. I will mention that I dismantled the fan in the smugglers box and thoroughly cleaned/adjusted the container to insure that the fan operates as intended.) I now get temps in the 40's and typically have to turn down the thermostat to avoid freeze ups.

I'm interested in the fan that Jim mounted and have been in contact with a company called Vintage Aire about a serpentine condenser to supplement what I currently have.