Question on 2 groove versus 1 groove compressor

[64Rivvy]

My original compressor (64 Riviera) needs to be rebuilt.  I really would like to replace it with one of the new Pro6Ten compressors since they are quieter, more efficient and will actually be cheaper than a rebuild.  Quote to rebuild the original is about $500 and it will take roughly 6-8 weeks.

 

The problem is that the Pro6Ten compressors are 1 groove and made to work with one belt.  My original compressor is a 2 groove pulley that's designed to use 2 belts.  Oddly enough, right now the previous owner was running it with just 1 belt since the A/C system was not being used.

 

Do I need both belts, or can I just use one belt and go with the Pro6Ten.  Trying to make sure that will work and was also trying to understand the advantage and the reason for 2 belts in the original stock configuration.

 

Thanks.

Edited February 25, 2016 by 64Rivvy (see edit history)

[Matt Harwood]

GM used the A6 compressor on a wide variety of cars, many of which only used a single belt to drive the compressor. I'm not sure why the Riv used two--maybe for NVH reasons? Was there something about the power pulses of the Nailhead that would have been transmitted through the belts? Was there something else being driven by one of the belts and it was a packaging decision? Did they need two because of how it was positioned and there wasn't adequate belt "wrap" on the pulley to guarantee traction at all speeds? I don't rightly know.

 

That said, if the manufacturer of the new compressor feels that one belt is adequate, then it should be good enough to install it that way. A newer compressor is likely lighter and will offer less drag, likely making two belts unnecessary.

[RivNut]

The Nailhead, as used in the early Rivieras, uses a two belt pulley system because of the contact patch area of the belt with the pulley.  Because the a/c belt also runs the alternator, there is not a very big contact patch between belt and pulley.  By running two belts, that contact patch is doubled.  Trying to run one belt on the a/c  -  alternator pulleys would result in slippage.  Your alternator wouldn't charge your battery properly and your compressor would not run at 100%.  If you were to run the two belt pulley on the water pump then run a single belt to the alternator and a single belt to the a/c compressor, you could run one belt for each accessory.

[Seafoam65]

                  You can get a Pro 6 Ten compressor with two grooves according to the Old Air Products website.

[64Rivvy]

                  You can get a Pro 6 Ten compressor with two grooves according to the Old Air Products website.

 

Where are you seeing that?  I only see the two grooves on the Sanden style.  The Pro6Ten all show one groove only and Vintage Air said they only make them with one groove.  If they can be had with 2 grooves that would solve my problem. 

[Seafoam65]

                 You are right......I had read a couple of weeks ago that they were available with two grooves.....this is not the case.

However, I have discovered that Four Seasons lists a brand new not reman A-6 Compressor  with two grooves under part number

58088. It has a 24 month warranty. This is what I would go with if I were you. A lot of people are selling them online, including Amazon

[fatbuick]

The clutch recently died on my original compressor so I decided to update it to a modern rotary model for half the price.

It's a Tama TM16HD GM Pad 12V 2A and comes with double pulleys, GM style pad for hose connectors. This means you could reuse the original hoses. One modification would be to shorten the lower section of the metal pipe next to the compressor by 82mm to bring the hose mount end forward to the shorter compressor.

I opted to have new hoses made re-using just the section coming off the Suction Throttle Valve.

The mounting holes are almost the same as original. I just had to file the holes on the original bracket inwards slightly and used 5/16" SS Bolts. The rear support bracket is not needed and replaced with a an L-shaped bracket down to the rear alternator swing bolt.

It works a treat and the old school guy even still had R12.

[Bill Stoneberg]

I got a Sanden from Vintage Air with 2 belts.

[64Rivvy]

Bill,

for the sanden from vintage air, did you have to fabricate a bracket? I really don't want to mess with any of that if I can avoid it.

The four seasons sea foam mentioned would be perfect, however I've read some reviews to stay away from any of the four seasons parts. Not sure if anyone has experience with four seasons parts here.

[Bill Stoneberg]

No,  It took a little drilling but it fit on the original bracket.

 

Take a look at post 35 on this thread..  Matter of fact, take a look at the whole thread as there are lots of pictures.

 

http://forums.aaca.org/topic/115312-vintage-air-ac-conversion-for-1st-gen-rivieras/page-2?hl=vintage

Edited February 28, 2016 by Bill Stoneberg (see edit history)

[RivNut]

In post #3 of this thread I made reference to running separate belts for the a/c and the alternator rather than running double belts and pulleys.  If you'll look at the last post (#102) in the thread in this link, you'll see an example of one belt/pulley for each unit. 

http://forums.aaca.org/topic/115312-vintage-air-ac-conversion-for-1st-gen-rivieras/page-6?hl=vintage

 

Ed

[66Lincoupe]

Reviving an older post. My daughter and I installed the Old Air Products HVAC system in her '64 that uses the Pro6ten compressor with a single groove. While the system works good we shred a belt every few weeks. I was looking at the thread referenced in the last post here and see the belt setup, and I tried it using one of the belts I had used when I bypassed the AC to run the alternator and the longer belt to wrap the AC. This setup slips worse than the single belt running the alternator and compressor together. 

 

I've tried the factory width belts and tried narrower and wider and still end up wearing the belts from slippage. There is just nowhere near enough wrap to keep any setup I have tried from slipping.

 

It's been a few years, and this thread came up when I was searching for a double groove clutch/pulley for this compressor (actually trying to find the manufacturer). 

 

Does anyone here happen to know who makes this compressor? I've contacted Old Air Products and they would only tell me that they don't offer a dual groove option.

[fatbuick]

I think there must be something wrong with the compressor if you're shredding belts.

The details of my compressor which does have twin belts is in this thread Feb 2016

[bodayguy]

I have the Pro6Ten compressor (single pulley) on my Riv, it looks just like yours. I have not had an issue with the belt yet, but it's only been on there for a few months.

 

That said, the compressor did not fit without some modifications because the bolts stick out so far they slam into the alternator bracket.

Edited August 15, 2019 by bodayguy (see edit history)

[KongaMan]

22 hours ago, 66Lincoupe said:

Does anyone here happen to know who makes this compressor? I've contacted Old Air Products and they would only tell me that they don't offer a dual groove option.

 

OAP seems to half-ass a lot of stuff.  Seems to me that a part advertised as a replacement for the original would have the same configuration.  That's not much contact area on the pulley for a single-belt, heavy-load application.

 

Hate to ask the obvious question, but how do you check the belt tension?  The standard shade tree methods (push until your finger turns white, 1/4" deflection, etc.) are notoriously inaccurate.

[TexRiv_63]

On ‎2‎/‎25‎/‎2016 at 2:02 PM, RivNut said:

The Nailhead, as used in the early Rivieras, uses a two belt pulley system because of the contact patch area of the belt with the pulley.  Because the a/c belt also runs the alternator, there is not a very big contact patch between belt and pulley.  By running two belts, that contact patch is doubled.  Trying to run one belt on the a/c  -  alternator pulleys would result in slippage.  Your alternator wouldn't charge your battery properly and your compressor would not run at 100%.  If you were to run the two belt pulley on the water pump then run a single belt to the alternator and a single belt to the a/c compressor, you could run one belt for each accessory.

Very true - I have a similar setup on my 63 Olds. When I first got it, the PO had switched the alternator for a single groove pulley model so it only had one belt. It squealed, slipped and burned no matter how much I tightened it every time I turned the compressor on. I changed out the alternator, put on a second belt, no more problem.

[TexRiv_63]

On ‎2‎/‎27‎/‎2016 at 7:51 AM, Bill Stoneberg said:

I got a Sanden from Vintage Air with 2 belts.

I also used the Sanden on my 63 Riv years ago as part of a total  Vintage Air conversion. I was able to use the front bracket with a little filing as Bill said but you do have to fabricate a simple rear bracket to support the rear of the shorter compressor. If you are adding the new compressor to an otherwise original factory air setup you may want to consider the Sanden SD7H15 compressor. This has a higher output and capacity than the more standard SD508. I just used one of these on a 66 Dodge with a dual evaporator system and it works great.