Sanden 508 on a Factory GM System?

[Ford Assassin]

Hey guys, I bought a Sanden 508 and Kwik Performance bracket for my '86 K5 that had a R4 radial style compressor from the factory. The rest of the system is stock except a new acumulator and varible oriface tube. I plan on using a R12/R134 replacement called Envro-Safe which is suppose to be colder than either R12 or R134 (according to reviews).

Anyway, I went to a local A/C shop with the truck and had custom hoses made. As I was paying for the hoses the guy decides to say, "You know that Sanden 508 isn't big enough for the factory GM evap, right?". I wasn't too happy he is telling me this after I just spent $100+ on custom hoses.

It doesn't sound right to me, but I am curious to hear what you Sanden conversion guys have to say. Since my K5 is in the middle of a 2wd conversion I have not run the system yet.

Thanks!!

[Firebirdjones]

I did this exact swap on my 72 blazer when I installed the 6.0/4L60E.

I used the Kwik Performance relocation kit which actually requires that you use the Sanden compressor (You don't have a choice with these brackets).

Mine works just fine. I haven't tried the new freon you mention,,,I'm just using good ole 134 and it cools fine. Those Sanden compressors are fairly efficient and don't take as much HP to turn them either.

I'm thinking what your AC guy probably means is that the old R12 condensors aren't that efficient at cooling 134. For 134 freon to work more effectively it needs the 134 style condensor which has a higher fin count and looks more like a high efficiency radiator where as your R12 condensor looks more like a cheap transmission cooler.....make sense?

Yes,,,the system would work more efficiently and blow colder with the 134 specific condensor, the problem with going to the aftermarket 134 condensor is that you'll be making more custom lines to mate with the existing setup, so you'll have the cost of the condensor and more custom lines to put a dent in your wallet. Some guys do it. I elected not to simply because I am using a POA conversion valve, and I figured if I were to go as far as to change the condensor, I may as well change the rest of the system to the better dryer/orifice tube setup. More money!!!

The way it is, it cools the blazer fine, even down in the Phoenix heat I can be comfortable. You could always try it and see how you like it,,,if it works fine for you then life is good,,,if it's not cold enough you can change the condensor at a later time and only be out the cost of freon....

[Ford Assassin]

Thanks for the reply, but I don't think we can compare our systems exactly the same though since yours is the expansion valve setup and mine is the the oriface tube setup.

I am not sure I get what you mean regarding the Kwik Performance brackets comment. The brackets will accept a Sanden 508 or 709 style compressor (a longer version of the 508, same mounting 'ears').

I forgot to mention that I replaced the older style condenser (tube and fin) with the newer style (bar and plate). It was a direct drop in replacement, prob because they know everything is running the more demanding R134 these days.

[Firebirdjones]

Well,,,,if you replaced the old style (tube/fin) condensor with the new style (bar/plate) for 134,,,,then there is no problem. I'd say your AC guy is mistaken. People use these little Sandens for all kinds of retro swaps.

The new style condensor you have is made for the less efficient 134, and the sanden compressor works just fine.

I compared my system because it's basically the same swap. The only difference is I elected to use the POA valve rather than use an orifice tube/dryer setup (for fitment reasons, dryer won't fit up by the box very well). Your truck already came from the factory with the orifice tube/dryer setup.
The orifice/dryer setup works better in that it doesn't cycle the compressor as often. My POA cycles the compressor more than I would like it to and is off for longer periods, but they both work.


What I meant about the Kwik Performance brackets is that they only accept the little Sanden compressors, (mine even had a specific part number to use).

With your sanden, new style freon, new style condensor to go with it, and the orifice/dryer setup, she will blow cold enough and work extremely well.

If it makes you feel better, my old 79 1 ton 454 still runs it's OEM compressor (the big one ) and I converted that to 134 many many years ago. It came factory with the orifice/dryer setup and I left the stock R12 style condensor. I simply flushed the system and recharged with 134 freon and oil. It freezes you out of there even with the less efficient condensor and 33 year old compressor

[Firebirdjones]

Here's mine. Same setup other than the fact that I'm using a POA rather than the orifice/dryer (I didn't have the room). Same compressor with a less efficient r12 condensor still in mine. Blows cold.

Yours should work even better with the orifice/dryer setup and a better condensor.



Here is a shot of the orignal condensor, at this point I'm still hooking the system up...

[Firebirdjones]

And to make the condensor work a little more efficiently I made this piece out of aluminum to force more air through the condensor rather than around it. Made one for the bottom too so it's all enclosed.

[J Knight]

My 82 a/c set up is still original and I've been wanting the complete vintage air system($1335). With all that is needed for a sandon compressor swap with factory system, i.e. compressor, evaporater core, condenser, dryer, mounting brackets, and hoses, are we talking about the same money for this as vintage air?
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[Firebirdjones]

Originally Posted by J Knight

My 82 a/c set up is still original and I've been wanting the complete vintage air system($1335). With all that is needed for a sandon compressor swap with factory system, i.e. compressor, evaporater core, condenser, dryer, mounting brackets, and hoses, are we talking about the same money for this as vintage air?
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With an 82 I personally wouldn't bother with all that. You already have the more desirable orifice/dryer setup. The Condensors in these trucks are so huge that I find they still work well with 134 even though the condensors aren't as efficient, the large surface area sort of bandaids that problem.

I simply converted my 79 to 134 using all the stock stuff (IE: compressor, condensor, orifice, dryer). Just a good flush of all the parts to remove the old oil, and recharge with the new stuff. Like I mentioned, that thing will freeze you out of the cabin. It only cost about $150 at the time for the freon and the new 0-rings I installed throughout the system, and a new dryer (since I had the whole system open).

That's a heck of alot cheaper than $1335 for a vintage air setup, and I guarantee it blows just as cold

I actually hear alot of complaints from the vintage air guys anyway that are doing retro swaps that they don't blow quite cold enough. I was talking to the local AC guy about that when I had my lines made for my retro swap in the 72. He told me the vintage air setups are made to be so compact to fit tight spaces that the A-coil is too small to do it's job, and the condensors, although made to be more efficient for the use of 134, really need to be larger also. Since they seem to have trouble cooling the freon because of their smaller size, the high side line pressures get dangerously high, so you in turn, can't put as much freon in the system, and you get sub par cooling as a result. It works fine when you live with ambient temps of 90 or below. Anything above that though and people are complaining.

When it comes to AC,,,,bigger is better.

[Restrorob]

Originally Posted by Ford Assassin

I plan on using a R12/R134 replacement called Envro-Safe which is suppose to be colder than either R12 or R134 (according to reviews).

Not sure about their R12/R134 replacement, But I can tell you this FA....

I had a leak in my house AC package unit, I repaired the leak and pulled a system vacuum. Called the local HVAC guy and he wanted $280 to re-fill with R22, I found Envro-Safe had a replacement for this so I charged it myself for 60 bux.

The average duct air temp nearest the return register is 48 to 53 degrees with R22, With this Envro-Safe in there I'm getting 43 degrees and 46 at the other end of the house. The AC kicks on and runs less time saving me money on my electric bill.

Since Envro-Safe works this good in my house AC, I can't wait to try it in one of my vehicles....

[jjzepplin]

I will be watching this as I am doing the same swap

[Ford Assassin]

Thanks for the responses guys. Soon as I am done with my 2wd conversion I'll be buying a few cans of Enviro-Safe, an oil charge, a new accumulator, and variable orifice tube and charging the system. I'll report my findings.

Take care!!