L67 swap A/C

[Quaraxkad]

I have an L67 swap in my 92 Cutlass, which I never bothered to hook up any of the A/C for. I want to do that now and am in the process of collecting parts, but I've found conflicting information on what lines are needed from what cars. I have all the original lines from the 3.1 LH0. I should have most of the lines from the 04 Impala SS donor. I think I have some other random lines I may have grabbed from junkyards while working on the swap years ago.

 

Does anybody know for sure what A/C lines will fit?

[Bake82]

The best bet is 98/99 Lumina LTZ/Monte Carlo Z34 with the 3.8.  Grab all the lines in the engine bay off one of those cars, 

6-7 yrs ago I bought the hardlines that connect to the firewall directly from GM.  Wonder if you could do the same?  

 

I also believe that lumina Z34's have same lines that can work, but I cannot confirm this.  

[55trucker]

I'm going to differ with you on this Kyle.......

what OP needs is the necessary A/C piping from a 1st Gen Regal with the 3.8 engine.

If you intend on keeping as much as your car is currently fitted with you'll need the a/c compressor manifold hose assembly that was fitted to the 3.8 Regal & a new rebuilt pre 94 compressor.

Everything prior to 94 is R12 based, everything post 93 is R134 based. When GM introduced 134 in 94 they changed ALL of the A/C line fittings thread pitch so NOTHING from prior & post can be used together.

My suggestion to you is to keep your 92 car all 92, get that old 92 3.8 manifold hose assembly & purchase a new *rebuilt* pre 94 A/C compressor, even the manifold hose assembly changed in 94 because GM redesigned the back end of the compressor housing for 94 so the old manifold hose will not attach to the newer design compressor housing. 

Purchase yourself a new receiver/dryer as well as a new orifice tube.

Go into Rockauto, search 92 Regal, they still house most of what you'll need.  

[Black92GS]

Just now, 55trucker said:

I'm going to differ with you on this Kyle.......

what OP needs is the necessary A/C piping from a 1st Gen Regal with the 3.8 engine.

If you intend on keeping as much as your car is currently fitted with you'll need the a/c compressor manifold hose assembly that was fitted to the 3.8 Regal & a new rebuilt pre 94 compressor.

Everything prior to 94 is R12 based, everything post 93 is R134 based. When GM introduced 134 in 94 they changed ALL of the A/C line fittings thread pitch so NOTHING from prior & post can be used together.

My suggestion to you is to keep your 92 car all 92, get that old 92 3.8 manifold hose assembly & purchase a new *rebuilt* pre 94 A/C compressor, even the manifold hose assembly changed in 94 because GM redesigned the back end of the compressor housing for 94 so the old manifold hose will not attach to the newer design compressor housing. 

Purchase yourself a new receiver/dryer as well as a new orifice tube.

Go into Rockauto, search 92 Regal, they still house most of what you'll need.  

One issue you may run into there is that 3800 series 1 powered cars all used the HR6 style AC compressor vs the V5 compressor that the 60 degree V6s and the 3800 series 2 cars used. 

A 1996 Buick Regal 3800 would have had a 3800 series 2 from the factory, so you might need to look for the AC components for one of those. 

 

[Quaraxkad]

Reviewing some components other than lines...

I just checked the part numbers (3093285) for the evaporator core, and they're the same part from '88-'01 in just about every W-body, including 92 Regal, 92 Cutlass, 98 Monte. So at least the fittings there should bolt up no problem from any donor.

The condensors are the same part number (52452050) from 89-93 and 94 Lumina (did it still get R12 that year?), and a second part number (52481282) for the rest of 94-01. Aftermarket lists them both as having 3/4" - 16 thread inlet and outlets, good for R12 and R134, but different core thickness (18mm and 25mm), and slightly different core dimensions and styles. Other than that they seem to be the same, possibly interchangable. I already do have a brand new 89-93 condensor I bought several years ago and never installed.

[Black92GS]

59 minutes ago, Quaraxkad said:

Reviewing some components other than lines...

I just checked the part numbers (3093285) for the evaporator core, and they're the same part from '88-'01 in just about every W-body, including 92 Regal, 92 Cutlass, 98 Monte. So at least the fittings there should bolt up no problem from any donor.

The condensors are the same part number (52452050) from 89-93 and 94 Lumina (did it still get R12 that year?), and a second part number (52481282) for the rest of 94-01. Aftermarket lists them both as having 3/4" - 16 thread inlet and outlets, good for R12 and R134, but different core thickness (18mm and 25mm), and slightly different core dimensions and styles. Other than that they seem to be the same, possibly interchangable. I already do have a brand new 89-93 condensor I bought several years ago and never installed.

When it comes to evaporators, the real test would be checking the part number for a 92 Regal with the 3800 against one for a 92 cutlass. If the part numbers match, you should be OK there. 
 

88-95 Regals with the 2.8/3.1/3100 would have had the same AC setup as the other Ws of the same year. The 3800 series 1 cars, of which the 90-95 Regals were the only Ws to use it, used a completely different AC compressor and AC setup(Cycling clutch vs variable displacement compressor) Some parts might match and interchange with other Ws, while others won’t. 
 

Just something to keep in mind when cross shopping parts. AC parts for a 92 Regal with the 3.1 should all match a 92 cutlass, where as parts for a 92 Regal with the 3800 may not all be the same. 

Edited Wednesday at 04:53 PM by Black92GS

[55trucker]

I went thru some of this non-compatible B.S some 11 years ago when I updated my A/C system to 134. 

I had already purchased a newer 134a compressor to replace the original R12 compressor that was leaking, at THAT time I didn't realize that the manifold hose assembly ends (fittings) had been redesigned for the 134a systems.

Seeing as I HAD to purchase the 134a manifold assembly for the redesigned compressor... I did NOT want to replace all of the other hardware, the new manifold would NOT fasten to the older receiver/dryer because the threads were altered........

all of this fell into play as I had also updated the brake vacuum booster, the larger booster required a *newer* 134a liquid side A/C delivery pipe. The newer pipe was redesigned to go under & around the larger dia booster & would NOT fasten to the older design receiver/dryer, the fitting threads were not the same.

I had to cut off the ends of the newer pipes & cut off the ends of the original & swap the old fittings to the new pipes & tig them into place.

Hopefully you can avoid all of the B.S if you keep everything compatible.

The 96 V5 compressor is near identical to the older V5 with respect to its *clocking*,  what IS different (besides the rear housing casting) is the mounting points openings...where the older item has threads cut into the flanges the newer design sees thru openings with no threads cut. 

 

 

 

 

[Quaraxkad]

I'm not sure I'm 100% following your suggestions. It also conflicts with one of the *very* old L67 swap guides from motorswap.org, which says you need 3.4 DOHC (assuming LQ1?) lines. If *that* is true, then I already have all the correct lines because they are shared with the LH0 in the '92 Cutlass.

I'm posting photos and what I've found so I can try to decipher the specific differences between at least these three models.

92 Cutlass, 3.1 LH0 and 3.4 LQ1:

 

92 Regal, 3.8 L27:

 

98 Lumina LTZ, 3.8 L36:

 

 

All of these share the same evaporator, so that's not an issue.

 

There are two condensors, they have slightly different dimensions (and may or may not physically fit if interchanged), and while the inlet and outlets apparently have the same fittings, they are positioned slightly different.

52452050 (89-93 and 94 Lumina):

52481282 (94-01):

 

There are several different driers. Looks like all w-body up to 93, plus 94 Lumina all have the same one with threaded connectors, one male and one female. There's another from 94-97 that *looks* the same with one male and one female threaded, and a service port added. Possibly interchangable. The one in the 98 Lumina is unique to only the 98-01 Lumina and Monte, with one threaded and one o-ring compression fitting. These are obviously not interchangable without also changing both lines.

2724686 (87-93 and 94 Lumina):

2724929 (94-97):

01132767 (98-01 Lumina and Monte):

 

 

 

The compressors probably have many versions, but just looking at these three cars we have: 89018893 in 89-93 and 94 Lumina, all without 3.8L. 89019355/1522130 in 89-94 with 3.8L. 89018897/1521662 in 96-04 with 3.8. Supercharged 3.8L 95's (and 94 S/C Regals) got their own compressor, 19169371/1520434. Between these there are at least three different fitting types: HD6, HR6, and V5. The aftermarket for these is all mixed up, showing multiple types available for the same car, so I don't know which is which! 

For comparison, here's the back of a V5:

And an HR6 (suction and discharged are swapped but otherwise looks the same aside from being polished and the rotation which may be the part itself and/or just the photo position):

Another labeled HR6 that looks completely different from the previous:

And I couldn't find a clear picture of an HD6, it might just be a mislabeled HR6.

 

Now for the lines...

From the drier to the evaporator. 10223050 in 88-93 and 94 Lumina. 19244605 in 94-97 (also listed for 95-97 Lumina and Monte even though there's a separate part number for those). 10445945/1531213 in 95-01 Lumina and Monte.

From the evaporator to the condenser. 10220973 in 89-93 and 94 Lumina. 1533130/10190636 in 94-97. 10407722 in 98-01 Lumina and Monte.

From the compressor to condenser and drier. 14099685 in 92-94. 52362087/1530113 in 92-93 Regal 3.8L. 10226168/1530241 in 94-95 Regal 3.8L. 10407721 in 98-99 Regal and Lumina 3.8.

 

Now... Have I gotten myself any closer to picking which components and lines I need?! I don't think so!  I assume I will need a compressor out of another 3.8, maybe specifically a Series II 3.8, just to get it mounted to the engine?

[55trucker]

Putting all of the *hardware compatibility* aside for a moment....

what ECM/PCM are you using to drive that L67?

Are you using the 1227727 case or the 1614936 case?.........with a burned chip tune for an eeprom

These are OBD1..

or are you using an OBD2 pcm?

[Quaraxkad]

OBD2 out of an 04 Impala SS.

[55trucker]

Ok, that's a start, that PCM is programmed to control  a CVC compressor, (compact variable compressor), did you pull the supercharged powertrain from the same 2004 Impala vehicle including that compressor?

Edited 23 hours ago by 55trucker

[Quaraxkad]

I had a ton of PCM issues in the beginning, so I had to go back and double-check what I ended up using. I confirmed it is a 04 Impala SS PCM, same as the engine and trans, but it's from a different donor purchased separately.

[Quaraxkad]

A CVC compressor used in 04-08 and 09 LaCrosse 3.8L is a completely different mounting design from *all* the others posted above.

I bet none of the others would even fit. And looks to have very different fittings on the back...

This is an 04 Impala SS diagram:

Edited 5 hours ago by Quaraxkad

[55trucker]

12 hours ago, Quaraxkad said:

A CVC compressor used in 04-08 and 09 LaCrosse 3.8L is a completely different mounting design from *all* the others posted above.

 

I bet none of the others would even fit. And looks to have very different fittings on the back...

 

 

I see, but the powertrain you have in the car is from the same 04 Impala?......so the a/c compressor mounted to that block would be the cvc unit....and that's what currently still mounted to the engine?.....if you've removed the compressor what are you using for a pulley to take the place of the compressor?

[Quaraxkad]

Yes, there is currently the original 04 Impala compressor installed, but I will need to replace it. It's been disconnected from the lines for years since the initial swap and the inlet and outlet have not been plugged, who knows what kind of gunk has gotten in it. So I am replacing *everything* except (if I can avoid it) the evaporator.

[Black92GS]

13 hours ago, Quaraxkad said:

A CVC compressor used in 04-08 and 09 LaCrosse 3.8L is a completely different mounting design from *all* the others posted above.

I bet none of the others would even fit. And looks to have very different fittings on the back...

This is an 04 Impala SS diagram:

One thing to be careful of there is that 2004 was a bit of a transitional year. A 2004 Lacrosse is a 3rd gen W and came with the 3800 series 3, while the 2004 Monte/Impala was still a 2nd gen and came with the 3800 series 2. 

Compatibility wise, you’re very much going to be stuck running a compressor compatible with a 2004 Monte SS if you want any hope of things functioning properly. The other potential gotcha is that 2nd gens also ran a BCM. There is a possibility that the PCM requires input from the BCM in order for the AC compressor to run correctly in the first place. 
 

[Quaraxkad]

4 minutes ago, Black92GS said:

Compatibility wise, you’re very much going to be stuck running a compressor compatible with a 2004 Monte SS if you want any hope of things functioning properly.
 

Because of the physical mounting, or because of the PCM? I can swap PCM if needed to use a different compressor, but If i'm limited to this 04-08 compressor mounting style, I will almost certainly need to make custom lines since they use a completely different line configuration.

[Quaraxkad]

I'm looking at the 04 Impala FSM. The BCM *is* part of the system, but it's only a A/C Request Signal which connects to the HVAC Control module. Since I'm not using the Impala control module, I don't think that matters. I am using the Cutlass module. I also don't see any special circuitry for the CVC function. It's just a normal looking clutch either off or on, no other electronics for the compressor.

Edited 4 hours ago by Quaraxkad

[55trucker]

I'm not familiar with the series 3 L67, I've only dealt the series 2, is there any sort of block casting redesign that will prevent one from fastening the V5 compressor to where the cvc is mounted?

[Quaraxkad]

This is a Series II L67.

[Black92GS]

11 minutes ago, Quaraxkad said:

I'm looking at the 04 Impala FSM. The BCM *is* part of the system, but it's only a A/C Request Signal which connects to the HVAC Control module. Since I'm not using the Impala control module, I don't think that matters. I am using the Cutlass module. I also don't see any special circuitry for the CVC function. It's just a normal looking clutch either off or on, no other electronics for the compressor.

Do you know what the AC request signal is though from the BCM? On the Cutlass, the request is in the form of a power or ground signal applied to a specific PCM pin. The PCM will then use a combination of other inputs to determine if and when to allow the compressor clutch to engage. Not having proper input from the powertrain side of things on the Cutlass PCM might not allow it to enable the AC compressor.
 

On a 2004 Impala, that AC request signal from the BCM may very well be in the form of a communication between BCM and PCM rather than a simple power or ground switch. From an operational perspective, the V5 adjusts internally based on refrigerant pressures….so the option to bypass everything and run a separate toggle switch to enable the compressor might be required in the end anyways. 

[Quaraxkad]

In the 04 Impala it's the Class 2 Serial line, shared with the BCM, PCM, HVAC, everything really! If I knew the protocol I could potentially simulate it using an Arduino, like I'm doing for the ALDL input on my UB3 cluster tachometer. Or I can still just swap the PCM. In either case it looks like the Cutlass HVAC module and whatever PCM I use need to be able to communicate.

Edited 3 hours ago by Quaraxkad

[Black92GS]

1 minute ago, Quaraxkad said:

In the 04 Impala it's the Class 2 Serial line, shared with the BCM, PCM, HVAC, everything really! If I knew the protocol I could potentially simulate it using an Arduino, like I'm doing for the ALDL input on my UB3 cluster tachometer. Or I can still just swap the PCM. In either case it looks like the HVAC module and the PCM need to be able to communicate.

Swap the PCM with what though? The cutlass PCM won’t run the L67. A 3rd gen PCM from a 3800 series 3 car won’t run a series 2 L67 either…and even then it would still rely on BCM input for the HVAC. 

[55trucker]

Taking a good look at the potential V5 contenders, it's apparent that you are going to be limited to a V5 from only the 3.8 engine family. Attempting to use a V5 *134a* from a '96 60 degree engine will not clock properly & the housing castings are different & not compatible with the 90 degree engines. This means you can't use an ODB1 V5 compressor at all.   

Since you're stuck with a 134a compressor you have to use the 134a hose manifold assembly which will not fasten to your existing receiver/dryer unless you go to the effort of cutting off the pipe ends & swapping them & tigging the old fittings to the new manifold. The same B.S I went thru.......... if one doesn't go the *custom* route you have to change both the receiver/dryer & the liquid & gas line into & out of the evaporator core.

[Quaraxkad]

27 minutes ago, Black92GS said:

Swap the PCM with what though? The cutlass PCM won’t run the L67. A 3rd gen PCM from a 3800 series 3 car won’t run a series 2 L67 either…and even then it would still rely on BCM input for the HVAC. 

I would use an older PCM from a different 3800, which is what every swap guide I read suggested in the first place. I used the engine-matching PCM because it ended up being easier, but there must be reasons previous swappers used late 90's PCMs instead. I also have an 2000 GTP and 98 Lumina LTZ PCM. Both of them tested to start and run the engine, but both had different transmissions and the LTZ is N/A. Both would need programming, but one of them might have a compatible switched ground AC request signal. Surely I'm not the first person to have AC in their L67 swap!?

Edited 3 hours ago by Quaraxkad