Posted by WOJ on February 08, 2000 at 11:00:00:
In Reply to: GM aletrnator posted by Pete on February 06, 2000 at 20:56:51:
A common problem when putting in a different charging system. You need to replace the alternator pulley with one of correct size for the belt size, which in your case is being determined by the crank pulley. Also another problem is matching the driven pulley (alternator) to the correct ALT driven speed. One reason Alternators are better than generators is because they are capable of producing more power at idle speeds (500-800 RPM's), so measure the crank pulley and then get an alternator pulley about half the crank pulleys sizes, which will run your alternator at twice the crankshaft speed. Also you need to know your vehicle TOTAL amperage usage (Lights, winch etc) to match the alternator up to it. Just putting in another ALT may lead to more problems, and running the belt farther in the pulley, as one post points to, is a good way to burn belts, and ALTS, as a V drive belt is made to run up on the pulley, with an Air space below the belt in the pulley, to disipate heat from both the belt and the front bearing of the ALT. More info can be obtained from alternator makers like, Leece-Neville or Neihoff.