Thread: Differences in McCulloch & Paxton Superchargers

The "nose" of the VS-57 output shaft pilots in a bushing in the end of the input shaft. All the lube going to the ball drive goes through there. The SN-60 output shaft ends before it gets to the input shaft, ( the real meaning of "short nose"?). There's a restrictive bushing in the end of the input shaft, to control oil flow.
There's a table of part #'s @
http://vs57.y-block.info/indextech.htm . See "Parts Interchange", "VS-57/SN".
Jim's idea of "parts interchange" was a little different from my intention to list "what it came with"; but, I think what he published is excellent!
Mounts and pulleys, all the installation parts, are different.
Mike M.

It may seem odd that I didn't mention the variable ratio pulley on the VS-57. Of course it's the most significant difference between the VS-57 and SN-60. I'd call that the "drive system"; and Dan asked about differences other than that.
In the chart I mentioned above, the '57 & '58 Golden Hawk is "VS57S". "Avanti SN" superchargers actually had serial #'s beginning with ML although Studebaker referred to them as type SN.
VS-57A & B, (Kaiser), had fiber discs behind the ball drive races. The races weren't pinned to keep them from rotating. McCulloch used clutch terminology in referring to some of these parts. Their patent papers explain that the races are supposed to rotate in the housing to keep the ball drive from being over stressed if it's driven too fast. An early SAE paper says they never had an output shaft fail in testing! The C version, which was sold in kits, and Stude's S version had pinned races. Depending on what races are used, they may have steel shims behind them.
As you can see in the chart, part #'s for the oil pump and it's individual components are the same for all units shown. Illustrations in the McCulloch service manual, which seems to be written for Kaiser, show a pump with the pickup offset to the rear, opposite of how part # 37055B is made. Maybe the very early version was 37309, and the offset was the difference.
It's possible Paxton/McCulloch didn't always change the part # when they redesigned a part, or that the parts lists we used to make the chart showed only the latest version of each part when the list was printed. Sources for the part #'s, and their dates of publication are listed after the footnotes.
Stude may have also substituted upgraded parts under an existing part #. Lots of folks have told me they got German ball drive parts from Stude, although the engineering drawing specifies the lower quality American parts. The chart shows drive balls and races the same for both Stude superchargers. Maybe that reflects what they supplied in Jan. '61 for the VS-57S, and Dec. '63 for the Avanti. It would be interesting to see if the #'s for the VS-57S parts are the same on a parts list from 1957.
Mike M.