My '76 has a/c with the old style piston (York) compressor. I want to drop the engine but the compressor has the lines attached. I don't know if the system is charged or not.

I do want to keep an a/c system; so, what's the best way to drop the engine? Unbolt the compressor from the engine and leave the compressor in the engine compartment or remove the lines? If I disconnect the lines, do I need to bleed off any residual pressure (if there is any)? I assume at least one of them would be a "high pressure" line. I seriously doubt the system is charged; however, you never know!

Thanks!

I doubt there is any freon left in it. You could hook up a gauge to read pressure to be sure.

If you plan to keep the AC system on the car, you will probably end up replacing some of the system anyway... compressor, lines, etc. Just remove the lines and drop the engine. If there is any pressure in the system, it will bleed out once you loosen the line a little bit. If its been sitting inoperable for some time, the system has probably lost its pressure already.

Bill, all you need to do is disconnect the AC lines and disconnect the power wire so you don't rip it. Everything else is the same.

If it has pressure, see what you can do to collect the R-12 instead of making our summers any hotter than what they are currently.

Sorry, the GREEN in me says that every act (spill) matters.

And be prepared for a HUGE sticker shock when you have to buy R-12 .............

The Cap'n

Research on line or check with an A/C shop, there are kits available to convert most older R12 systems to 134a. You'll more than likely need to purchase a new dryer too.

Thank you for all the feedback. I'm pretty sure all the freon is gone.

I'll replace the piston compressor with a new rotary one and most likely upgrade lines and whatever else is involved. I would really like to find a pulley like the one below to do an installation as shown in an earlier thread...

Check on the SAMBA site, looks like it might be a bus set-up ... what do you say, John?

I've been checking the samba on a weekly basis. Its a smog pump pulley from a 75 era bus or camper. If you find one, ask for two.

I've started looking. You would think that an install as clean as this would encourage one of our vendors to make a similar pulley.....

Why not use a smog pump pulley assembly from a 914?

Click to view attachment

There are lots of options.....I like the looks of the install I posted pics of. Also, I wonder how important pulley diameter is for this kind of install?

I am not sure the smog pump pulley assembly from the later 914's is sturdy enough to drive an A/C compressor, at least for very long. The smog air pump was a dinky little thing, while an A/C compressor, even a newer rotary style, will require a lot more drive power.

That was one of my concerns. I've never seen the pulley assembly in person so I couldn't tell for sure... This thread got me thinking though and I have another idea in the works.

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From Experience with an AC system in a 914.

1. Remove the battery from the tray.
2. Unbolt the compressor and lift it up and set it in the battery tray.
3. Drop the engine normally.

I would recommend an AC compressor kit from ICEAC. I have one on Betty's car, and it works great. Replace the lines and O-rings with R-134a compatible bits and upgrade the condenser fan if it is a DPD system. If you want better performance, get a 911SC condenser and mount it to the underside of the engine lid with a couple of fans. That will make the air in the cabin really cold.

I agree with Clay - that's one viable option. You won't be able to reuse any of the existing R12 lines if you convert to 134a (BTDT). R12 was meant to breath - which is unacceptable today. Even if you stayed with r12 the lines are so old they're essentially useless.

Good luck, and keep us posted with the results.

Also, the r134a molecules are considerably "smaller" than the old r12. Lines that work fine with r12 will generally leak r134a.

I actually just got one of these pulleys from a friend who had one in his shed. I'm looking at the Sanden compressors now. As soon as I have a compressor in hand it will go to my welder/fabricator with a fan shround and pulley bolted in place to make a mount base for the compressor.

I'm still thinking the smog pulley setup might be the best bet mainly because its supported in the middle via the bracket/bearing. A pulley set a couple inches out from the crank (no support) will put added stress on the engine bearings and internals. I'm not sure this is an issue but I have some experimenting to do. It would be easy enough to have an adapter machined to offset a pulley if the smog pulley assembly doesn't prove worthy enough.

I too was going to order a compressor soon. Once I receive it I was going to play around with multiple mounting locations and decide which is best. Cutting the engine tin isn't an option in my book. I was even thinking about possibly putting together a "kit" to offer. I will also have the ability to make my own custom hoses.

Ill probably start my own thread once I get started.

I would be very interested in seeing the solution you develop!

Sounds like you and I are on the same path Doug. I refuse to cut the tin. I think the 914 pulley would be stronger supported by three points close to the pulley itself. I found the sanden 508 with clutch and v belt pulley on ebay for 120. I don't want to cut the front trunk either. I'm interested in what you guys think about the airflow over the engine grill in the 914. I don't run a rain tray, so the 911 condenser would be more to my liking.

I have two concerns with running the condenser on the engine grill.. airflow and introducing heat into the engine bay. I looked into that option and you could easily run a sole modern condenser in that location but of course you would need fans for air flow. You would also be blowing hot air into the compartment. I'm not completely sold on it yet athough its still an option.

I would think it would be to heavy for the lid also , and reduce air flow into the engine bay

Clay put an engine-lid condensor on Betty's car. Hopefully he will comment on that setup soon. They say that it works; I would be cautious about doing it.

--DD

If done correctly, the condenser shouldn't hurt airflow much at all. If you mount a couple of small electric fans on it, it would probably improve airflow. In fact, were I to go that route I think I'd connect the fans so they are energized by the A/C Relay, but also mount a manual switch so that you could have the A/C off but still run the fans to maybe improve cooling on the really hot days.

Having said all this, what exactly *is* the airflow path thru the engine bay? If it is coming in thru the lid, where does it exit?

I'd be more concerned with pre-heating the air used for induction and for cooling than with any potential blockage.

The air comes in through the lid. A little of it gets sucked into the engine and winds up coming out the exhaust pipe. Most of it goes into the fan and gets dumped underneath the engine bay after it is used to cool the engine.

--DD

That is exactly what I did. But the condenser there is one of two I have on the car. The stock condenser is in the front trunk and is still hooked up. R134a has less performance than R12, and it needs more condenser to work well. Adding the 911SC condenser and a couple of 10" fans improved the AC function.