Marto303 Posted May 11, 2015 Posted May 11, 2015 As used briefly on the my 2.0L Blacktop Zetec, I say briefly as I only unpraded the alternator over winter and this was fitted at that time. However it is very slightly to large diameter for my set up and at idle was not turning the alternator fast enough to charge. Light weight Alloy 6 Rib 53mm dia across the ribs 57mm dia across the outside 15/17mm shaft dia £20 inc p&p
dombanks Posted May 11, 2015 Posted May 11, 2015 can you elaborate on the not charging/spinning fast enough as i need a larger one due to my smaller pulley running the alternator too fast....?
Marto303 Posted May 11, 2015 Author Posted May 11, 2015 Yes sure From what I can work your alternator needs to rev twice as fast as your engine rpm to operate correctly as they don't switch on till around 1600 rpm and shouldn't exceed 18000 rpm, ie engine 900rpm at idle = 1800 alternator rpm and 7500rpm max engine revs = 15000 max alternator revs, therefore your alternator pulley needs to be half the diameter of the crank pulley, well that's my understanding and if thats wrong I'm sure someone far more knowledgeable will be along to put me right.
dombanks Posted May 11, 2015 Posted May 11, 2015 your not far off marto as i understand it its the ratio of the pully diameter to the crank pully diameter. so a 2:1 ratio means the alternator would be running at 2x the rpm. i only asked as i need a larger one so it caught my eye.
TAFKARM Posted May 11, 2015 Posted May 11, 2015 Mart - I need a new alternator, would this one suit me?
Marto303 Posted May 11, 2015 Author Posted May 11, 2015 Russ, this is just the pulley not the alternator, but yes it should be right for a duratec. Measure the diameter of your crank pulley and count the number of ribs in the pulley and let me know.
Marto303 Posted May 12, 2015 Author Posted May 12, 2015 Just measured mine and its the same size sorry ... No worries thanks for letting me know
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