Automotive Air Conditioning Information Forum (Archives)

71403 on Sun December 27, 2015 4:47 PM

Retrofitting a GM V5 compressor onto a motor that didn't originally come with a V5. Have one from a '98 Buick Lesabre 3800 (4 Seasons # 58994) which correctly clocks the control valve and inlet/outlets. But the case only has 3 mounting ears and need one with 4 ears.

Is there a V5 that has the same rear configuration but with 4 mounting ears not 3?

Could use one that clocks the inlet/outlets more clockwise (when viewed from the rear) than the Buick compressor if needed.

GM Tech on Sun December 27, 2015 7:21 PM

Need one with four-- why? Almost every V-5 out there uses only 3, some only have 3 mounting bolts entirely front to back- I've mounted (for experiments) with only 2 ears on front head and 1 bolt on rear head and was just fine. If your bracket has room for 4 mounts on front- then you don't need all four- but you must have at least one mount on the rear.

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The number one A/C diagnostic tool there is- is to know how much refrigerant is in the system- this can only be done by recovering and weighing the refrigerant!!
Just a thought.... 65% of A/C failures in my 3200 car diagnostic database (GM vehicles) are due to loss of refrigerant due to a leak......

71403 on Sun December 27, 2015 10:07 PM

71403 on Sun December 27, 2015 11:02 PM

Compressor is mounted on the driver's side of engine, with it clocked correctly this one the middle ear is outboard. If I had the ear on the other side I can pick that ear up with a thrubolt to the passenger head so it's more rigid mounting. 3 ears would be fine if the middle ear was flipped 180 from this one while keeping the rear ports in the same position.

CorvairGeek on Mon December 28, 2015 8:09 AM

Try one from a '96 Buick Century with a 3100 V6, different mounting ear layout. The one that is machined off in the LeSabre configuration will be on this compressor, but I believe it has threaded holes versus through hole mounting, IIRC.

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Jerry

GM Tech on Mon December 28, 2015 10:43 AM

The front heads on V-5s can be rotated in 120 deg increments- the through bolt holes are on a bolt circle- I've done it a few times when needed. Watch for the coil flats position- there are usually two choice for coli rotation. oh and don't rotate the valve plate inside, just the head.

-------------------------
The number one A/C diagnostic tool there is- is to know how much refrigerant is in the system- this can only be done by recovering and weighing the refrigerant!!
Just a thought.... 65% of A/C failures in my 3200 car diagnostic database (GM vehicles) are due to loss of refrigerant due to a leak......

CorvairGeek on Mon December 28, 2015 7:00 PM

That's good to know. I never would have tried it myself after you described the no pump condition (from probably turning the valve plate too) from personal experience. Thanks!

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Jerry

Edited: Mon December 28, 2015 at 7:01 PM by CorvairGeek

71403 on Tue December 29, 2015 11:40 PM

I'd like that to work but there is a recess for the pin that comes up from mid-section that fits in a recessed hole so can't clock the front housing relative to the piston body. If I turn the front housing and piston section together the small port in the middle won't line up correctly with the valve plate.

GM Tech on Wed December 30, 2015 9:28 AM

That's right, that is the guide pin blind hole in front head- I had a brain fart- was thinking of H-6's - those are the ones that can be rotated. If it helps, the rear head can be up to 30 deg off center- as in the 3.1L engine application- it has the control valve at about 7:30 instead of 6 o'clock.

-------------------------
The number one A/C diagnostic tool there is- is to know how much refrigerant is in the system- this can only be done by recovering and weighing the refrigerant!!
Just a thought.... 65% of A/C failures in my 3200 car diagnostic database (GM vehicles) are due to loss of refrigerant due to a leak......

71403 on Thu December 31, 2015 10:07 AM

Can case halves be mixed and matched between compressors?

GM Tech on Thu December 31, 2015 5:10 PM

No case halves on a v-5- there is a front head, cylinder assembly and rear head.--all are interchangeable- except for thrust package stack-ups- the 2 washers and thrust bearing on front of shaft- I've done it, but you always take the chance there will be slop, or too much compression. Rear heads are all alike, until you get into high speed destroker mechanism- but that was only used on small 4 cyl engine applications you have about a 10% chance of seeing one of those. Control valves set points vary but probably not enough to cause the common builder issues- if wrong one used-you may freeze up after an hour drive in 80% humidity, but how often will that happen? Just shut it off for 5 minutes and go on...

There are v-7s out there as well which may fit your bill- they look a lot like v-5s- but are completely different except for mounting applications- the 97-2002 S-10s come to mind.

-------------------------
The number one A/C diagnostic tool there is- is to know how much refrigerant is in the system- this can only be done by recovering and weighing the refrigerant!!
Just a thought.... 65% of A/C failures in my 3200 car diagnostic database (GM vehicles) are due to loss of refrigerant due to a leak......

71403 on Fri January 01, 2016 1:52 AM

Found one with the mounting ear config needed - 95-01 f-body 3800 - 1135222

Curious what the eccentric is in the middle of the cylinder section is, also the center hole in the valve plate is drilled completely thru. The few others I've had apart don't have the eccentric or center hole drilled.






Edited: Fri January 01, 2016 at 1:56 AM by 71403

GM Tech on Fri January 01, 2016 10:50 AM

Uhm- that's the mechanical destroker I mentioned-(your 10% chance)-- when engine/compressor rpm's exceed 3800 or so- the centrifugal counterbalance mechanism allows discharge gas into crankcase and the compressor will destroke and free wheel- allowing basically for the compressor to shut off, without disabling the current to the clutch- and more power to the wheels- The Camaro 3800 had it, while the V-8 back then used an H-6 compressor till '97.

Should not be any big deal- how often will you need cooling while you have it floored?

-------------------------
The number one A/C diagnostic tool there is- is to know how much refrigerant is in the system- this can only be done by recovering and weighing the refrigerant!!
Just a thought.... 65% of A/C failures in my 3200 car diagnostic database (GM vehicles) are due to loss of refrigerant due to a leak......

GM Tech on Fri January 01, 2016 10:52 AM

Uhm- that's the mechanical destroker I mentioned-(your 10% chance)-- when engine/compressor rpm's exceed 3800 or so- the centrifugal counterbalance mechanism allows discharge gas into crankcase and the compressor will destroke and free wheel- allowing basically for the compressor to shut off, without disabling the current to the clutch- and more power to the wheels- The Camaro 3800 had it, while the V-8 back then used an H-6 compressor till '97.

Should not be any big deal- how often will you need cooling while you have it floored?

-------------------------
The number one A/C diagnostic tool there is- is to know how much refrigerant is in the system- this can only be done by recovering and weighing the refrigerant!!
Just a thought.... 65% of A/C failures in my 3200 car diagnostic database (GM vehicles) are due to loss of refrigerant due to a leak......