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Old 10-18-2012, 11:32 AM   #21
rfmaster
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Join Date: Oct 2003
Location: OC CA
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Re: CS-144 140amp alternator upgrade howto

Quote:
Originally Posted by motornut View Post
yup my 87/88 burbs had this
here is my 88 4X4 burb
That's a 12-SI alternator in photo which is only slightly bigger than OE 10-SI units used in 70's and early 80's trucks. The 10SI were factory rated 37, 42, 55, 61, and 63 Amp. While 12-SI where available in 78 and 94 AMP rating. 12-SI is a direct swap for 10-SI. The CS-144 is a 'big mama' of alternators and requires some bracket rework. They were OE rated 124-145 AMP, but can be modified with bigger rectifiers for higher current output. For a stock or near stock application I use a slightly larger diameter, deep groove 3/8" V-pulley. This way there is more contact surface between V-belt and pulley. The deep V pulley also prevents belts from being tossed. The only negative is that alternator turns slower at idle, but this unit has so much current output at idle that it is never an issue, unless there large surges while engine is idling. For about 95% usage it is more than adequate with plenty of ampacity to spare (lights, winches, fans, etc)

//RF
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