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Old 12-28-2021, 10:35 PM
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Quote:
Originally Posted by BillGrissom View Post
Sherm, the Sanden compressors are probably slightly better than R4. I think they have a swash-plate drive, like the Denso I took apart from my Plymouth. The 7-piston SD7 are newer and preferred. Double-acting, so essentially 14- pistons for a smooth output. I recall the R4 has a crankshaft w connecting rods and 5 pistons, single-acting. My Denso failed when the black anodizing wore off the aluminum pistons, to seize one in the aluminum bore. I think R4's can fail similarly.
R4 is a "Radial" 4 piston compressor, thus the R4 designation. It's GM predecessor was an "A6" meaning Axial, and 6 piston (actually 3 double acting=6). The Denso is in fact a similar design as the Sanden. Both are excellent compressors.
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