1972 LT-1 A/C compressor
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1972 LT-1 A/C compressor
Hi,
I want to replace my original A/C A6 compressor with a new one. Most new units (like Alma for example) have a 5'' pulley diameter.
My original one have a 5.75"pulley. Why there are 2 different types ? What is the technical difference ? I guess maybe a 5.75 is better for high rpms like the LT-1 is capable ?
Thank you in advance.
Chris
I want to replace my original A/C A6 compressor with a new one. Most new units (like Alma for example) have a 5'' pulley diameter.
My original one have a 5.75"pulley. Why there are 2 different types ? What is the technical difference ? I guess maybe a 5.75 is better for high rpms like the LT-1 is capable ?
Thank you in advance.
Chris
Le Mans Master
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From: Hermosa
That would be my guess as well. Larger diameter to handle higher RPM's. But really who is going to have the A/C on while turning 6500 RPM? It would also reduce the effort required by the engine, perhaps for low RPM (idle) when it's not making much power.
From reading I've done you're better off rebuilding the current compressor vs a replacement. Usually the only thing wrong is the front seal leaks.
From reading I've done you're better off rebuilding the current compressor vs a replacement. Usually the only thing wrong is the front seal leaks.
I guess maybe a 5.75 is better for high rpms like the LT-1 is capable ?
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My problem is that I had already given my compressor for a rebuild (here in Switzerland) and my clutch is now broken....
I would rather buy a new one instead of trying to fix my clutch and have another problem later!
I would rather buy a new one instead of trying to fix my clutch and have another problem later!
Le Mans Master
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From: Hermosa
The clutch can be replaced without replacing the entire compressor.
rebuild or new A6 compressor quality is questionable. If it were mine I’d just replace the clutch if it’s otherwise functioning normally.
rebuild or new A6 compressor quality is questionable. If it were mine I’d just replace the clutch if it’s otherwise functioning normally.
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Yes, I know that it is possible to change only the clutch. I don't know if the clutch was broken by the compressor... Now, it rotates freely by hand (it is not blocked).
Exact : the LT-1 A/C tach is 5'600 and W/O is 6'500.
Exact : the LT-1 A/C tach is 5'600 and W/O is 6'500.
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My engine can easily go up to 5'500 rpm and I think a bit more is also possible...
And for originalty of LT-1 A/C (which is for me important), I'll stay with a 5.75" pulley id possible.
It is quite difficult to find a new compressor with this pulley...and they cost about $ 600 :-(
Alma seems to be good (with some improvments).
And for originalty of LT-1 A/C (which is for me important), I'll stay with a 5.75" pulley id possible.
It is quite difficult to find a new compressor with this pulley...and they cost about $ 600 :-(
Alma seems to be good (with some improvments).
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From: Hermosa
I guess it depends on belt technology then. I regularly run my 77 up to 6300 RPM and have never thrown the belt off the A/C.
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From: Hermosa
Unless you're looking for originality I wouldn't worry about the diameter of the pulley and just don't run the A/C when reving it high.
Like I said run mine to 6300, no problems. I don't have the A/C running when I do it though. Originally a 5200-5250 redline motor in the 77. Never changed the A/C compressor, still a stock unit.
Like I said run mine to 6300, no problems. I don't have the A/C running when I do it though. Originally a 5200-5250 redline motor in the 77. Never changed the A/C compressor, still a stock unit.
Team Owner
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From: Redondo Beach, California
My understanding is that the AC compressors for Corvettes was modified by dishing the A6 pistons to produce a lower compression ratio. This slightly reduced their cooling capacity and parasitic drag.
The A6 compressors used a wobble plate...three pistons on one side of the wobble plate and three matching on the other side. Correct? The Germans before wwII built a wobble plate aircraft engine. It is, or was, on display at the Air Force museum in Dayton, Ohio.
The A6 compressors used a wobble plate...three pistons on one side of the wobble plate and three matching on the other side. Correct? The Germans before wwII built a wobble plate aircraft engine. It is, or was, on display at the Air Force museum in Dayton, Ohio.
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I agree that the belt tech is important : I had AC Delco belts previously and they jumped off the pulleys very easily. With now Dayco belts, no problems anymore !
6'300 rpm with 5'' pulley, I assume ? Good to know because I don't go until that (maybe 5'500 rpm ?). This means I would be able to buy a new Alma compressor with a good price.
6'300 rpm with 5'' pulley, I assume ? Good to know because I don't go until that (maybe 5'500 rpm ?). This means I would be able to buy a new Alma compressor with a good price.
Le Mans Master
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From: Hermosa
I agree that the belt tech is important : I had AC Delco belts previously and they jumped off the pulleys very easily. With now Dayco belts, no problems anymore !
6'300 rpm with 5'' pulley, I assume ? Good to know because I don't go until that (maybe 5'500 rpm ?). This means I would be able to buy a new Alma compressor with a good price.
6'300 rpm with 5'' pulley, I assume ? Good to know because I don't go until that (maybe 5'500 rpm ?). This means I would be able to buy a new Alma compressor with a good price.
I'm using Bando brand belts and have never had any issues with them at all, durable and last a long time.
This is the exact one I have now.
Navigator
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From: Oh
I agree that the belt tech is important : I had AC Delco belts previously and they jumped off the pulleys very easily. With now Dayco belts, no problems anymore !
6'300 rpm with 5'' pulley, I assume ? Good to know because I don't go until that (maybe 5'500 rpm ?). This means I would be able to buy a new Alma compressor with a good price.
6'300 rpm with 5'' pulley, I assume ? Good to know because I don't go until that (maybe 5'500 rpm ?). This means I would be able to buy a new Alma compressor with a good price.
Le Mans Master
Joined: Apr 2011
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From: Hermosa