Powermaster 12si Style GM Alternators

Product images may differ from actual product appearance.

GM has offered several series of alternators over the years, each time taking a step up in performance. The great thing about these alternators and aftermarket brackets is that for the most part they are interchangeable. Starting with the externally regulated 10dn alternator of the 1960s and moving all the way to the CS130D alternator of late, aftermarket brackets with rod end tensioners will interchange. The 2" mounting foot width is common to all of them and the 6.61" bolt spacing is common (except the CS130D. the CS130D is a 7.24" bolt spacing although many brackets will accommodate this.)

12si Alternators

100A Specifications

70A @ 2,400 rpm @ 13.2 VDC @ 77F

Operating Range: -40C to 150C

Max rpm: 18,000

140A Specifications

80A @ 2,400 rpm @ 13.2 VDC @ 77F

Operating Range: -40C to 150C

Max rpm: 18,000

Proof of Performance tag