Doug's A/C System, R&D/Build Thread Options

[76-914]

Looking good in the hood my friend. (IMG:style_emoticons/default/popcorn[1].gif)

[wingnut86]

Agreed (IMG:style_emoticons/default/biggrin.gif)

So, what's the weakest link in the A/C system?

I'm thinking ahead here:

1- condenser flow enough?
2- underdash unit is how efficient?
3- how much current draw from under dash motor?
4- we already know the newer Sanden is light-speed ahead in design and operation
5- wondering what the total power loss is to system overall, knowing it's better than 42 year old design

Hot and humid southern summers make or break the Type IV from experience.

Again, replaying devil's advocate here more for my sanity...

Dave B.

[stateofidleness]

Finally got to the car last weekend and snapped some pics of the compressor on my '73. It also looks like once the bolts are undone (I counted 4), that it would actually have enough hose length to be able to rest it on the rear deck lid. Planning on dropping the engine soon and was worried about suspending it, but seems like it'll sit up there nicely during the drop.

[zambezi]

I am curios to know what pulley you have to drive the york. It looks like it would be a similar setup to mine. When you get the engine dropped take a pic of the pulley or aim the camera in there now and try and get a pic off.

[dlee6204]

Agreed (IMG:style_emoticons/default/biggrin.gif)

So, what's the weakest link in the A/C system?

I'm thinking ahead here:

1- condenser flow enough?
2- underdash unit is how efficient?
3- how much current draw from under dash motor?
4- we already know the newer Sanden is light-speed ahead in design and operation
5- wondering what the total power loss is to system overall, knowing it's better than 42 year old design

Hot and humid southern summers make or break the Type IV from experience.

Again, replaying devil's advocate here more for my sanity...

Dave B.

When I first started this project, my initial intent measure and evaluate the the various efficiencies of the system and its components and play around with different options (Its the engineer in me). I'll probably still play around with it more once the weather gets warm again. Right now I would assume the limiting factor to be the airflow over the condenser and/or condenser size specially when converting to r134.

[dlee6204]

stateofidleness, Thanks for the pics.

I am curios to know what pulley you have to drive the york. It looks like it would be a similar setup to mine. When you get the engine dropped take a pic of the pulley or aim the camera in there now and try and get a pic off.

(IMG:style_emoticons/default/agree.gif)

[wingnut86]

I found the link to the company that built Jake Raby's setup for his wife's Super Beetle, as well as one they show for a bus on their site.

Link provided:

Gilmore Enterprises - VW and P-Car A/C

Looks like he still hasn't updated the kit he built for the 914, as the site link is still in progress for our cars.

Good images to check out though.

(IMG:style_emoticons/default/beer3.gif)

[rfuerst911sc]

I plan to make a AC system for my GT clone sometime in the future. I have a Sanden compressor not sure it it's a 507 or 508. The trick will be a mount to use on my 3.0 six. I also plan on using a condensor from a Porsche 993 and install it in front of the right rear tire in the fender well. I think I can get it in there with a Spal fan and have good air flow. That would help keep the hose run shorter. Regardless of refrigerant type I will use o-ring fittings as I think they seal better than flare. This post has given me a few ideas thanks.

[ClayPerrine]

Finally got to the car last weekend and snapped some pics of the compressor on my '73. It also looks like once the bolts are undone (I counted 4), that it would actually have enough hose length to be able to rest it on the rear deck lid. Planning on dropping the engine soon and was worried about suspending it, but seems like it'll sit up there nicely during the drop.

Take the battery out of the car and put the compressor in the battery tray. The hoses will be long enough, and you don't risk scratching or denting the rear deck lid.

[stateofidleness]

K guys, I wanted to dig in a little more on this because honestly I have always been curious about the AC in this car myself. I am planning on dropping the engine in this one for the first time so I started work on getting the AC stuff out of the way at least. Car is winning though... Without much documentation on this setup, I can't research the proper way to unmount it. At first I was attempting to take the entire thing out (compressor+bracket) in one piece and we found that it is still swiveling on a bolt directly underneath the compressor mount (you can see it in the pic). It appears this has been broken by a P.O., but I can almost forgive them because I can tell why it's broken. Absolutely no way to get any kind of tool on it.. tried everything!!!!

So then we tried unmounting the compressor from the base plate and got 3 of the 4 bolts off, but there's one near the firewall directly behind one of the pulleys that seems impossible to get at as well... no combination of wrenches or sockets seemed to help...

So I gave up and told Dad I'd be consulting the experts (IMG:style_emoticons/default/type.gif)

Took a pic of the bolt underneath that I can't get a wrench/socket on (seems to be a 14mm). Found some other markings on it and took some pics. I'll post in a few. There's still some original stickers and other markings on the very front but can't get a camera between the pulley and the firewall yet. Stay tuned!

The yellow arrows are pointing at the last bolt that seem to be holding the whole thing to the engine... no way to get a wrench on it though!! The blue arrow is showing the broken hole on the fan housing.




Here is closer view. The top pic is a bigger pic to give you some idea of where we're looking:

[stateofidleness]

Couple more... left them a little bigger because it's hard to find large reference images for stuff like this:

[stateofidleness]

Uno Mas. Markings on the visible side of the compressor (opposite the pulley):

[stateofidleness]

Couple more reference pics as I finished getting the compressor unmounted this week.

[dlee6204]

stateofidleness, Did you ever figure out how your compressor was driven off the front of the engine?

[dlee6204]

Not a big update but I did finish the pulley adapter. Now I just need to install everything one of these days and start testing it.

[dlee6204]

Version 2.0 is now up an running. I put a new motor in my car so I was waiting on that to try out the new stuff. Everything went together smoothly and so far no issues. I need to finish charging my system and then it will be smooth sailing just in time for the summer heat. (IMG:style_emoticons/default/shades.gif)




In order for the compressor to mount far enough back, I relocated the oil filler. I only needed to move it less than an inch but I went ahead and mounted it up higher. I like it better this way.



And for those who don't know I run CIS on my car so that's why it looks a bit different. (IMG:style_emoticons/default/smile.gif)



And the most exciting video to date...


https://www.youtube.com/watch?v=4LRnNZTDaTs

[dlee6204]

Oh and for those wondering, to set the timing I used the back of the flywheel and the small access hole. Its actually a lot easier to see the marks this way than having to stretch your body across the top of the engine.

[dlee6204]

Now for some boring stuff...

I thought I would give an update on some of my results. The other day I did and initial charge on the system and had the following results:

Ambient Temp: 75 Fahrenheit
Low Pressure: 40 psi
High Pressure:250 psi
Evaporator (Air Vent) Temp: 58 Fahrenheit

Here is one reference I use for the range of temperatures/pressures...

http://www.ackits.com/aacf/ptchart.cfm


From the initial test my numbers were a little high. From experience I knew the likely culprit was inadequate airflow over the condenser. Last year the squirrel cage fan in the condenser box froze up so I replaced it with a small electric radiator fan and I wasn't too happy with the way I mounted it and obviously that method didn't work too well so I reconfigured it today. Sorry, no pictures (IMG:style_emoticons/default/sad.gif) I mounted the fan on the underside of the condenser so that it pulls air. Worked great. My new readings are:


Ambient Temp: 82 Fahrenheit
Low Pressure: 33 psi
High Pressure:230 psi
Evaporator (Air Vent) Temp : 54 Fahrenheit

That's a temperature drop of 28 degrees! Not too bad. Now I need to go test drive it and see how low it goes. (IMG:style_emoticons/default/driving.gif)

[FourBlades]

Nice work!

I am sure a lot of people would like a working AC in their cars.

John

[dlee6204]

Just an update. I made a batch of extra adapters that I'd sell to anyone interested. Each would include the necessary hardware. Pulley not included. $85 shipped conus I apologize for the crappy pics.










I am also putting together at least two "kits" that I'll be selling shortly which includes the drive pulley, compressor, mount, hardware and everything necessary to mount a compressor on top of the motor. Stayed tuned for that.