June 5, 2019 at 6:27 am #225075
I have a 58W westerbek and would like to put on a new alternator was wondering what size I can go with ? would like to go as big as possible
June 5, 2019 at 2:55 pm #225076Bryan BywalecKeymaster
Are you willing to go to dual belts? I’ve heard that 110 amps is about as large as you can go with a single belt. The engine should be fine although it robs about 2-3 horsepower to do 110 amps. If you want something larger than that you might also add a switch to deactivate the unit when you find yourself in need of a few more horsepower in adverse conditions.
S/V Pelican, Hull 209
Siren Engineering, LLC
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June 5, 2019 at 3:26 pm #225077
just want what will fit on the boat, not sure what is on it. but I am sure that its original equiptment
June 5, 2019 at 3:28 pm #225078
will any marine alternator work as long as its under 110 amps ?
June 5, 2019 at 3:46 pm #225079figie47gmail-comParticipant
Check out the Hamilton Ferris PM 125
Works with a smart regulator and a single belt. Make sure the pulleys are in alignment.
June 5, 2019 at 6:20 pm #225080Miss KathleenParticipant
If the normal V belt is used a double pulley is required. You will most likely find that any alternator around 120A will have a double pulley.
A further improvement in order to maximize the 120A/130A alternator is to remove the standard regulator and install a smart regulator. The general rule is to have an alternator rating that is 25% of the installed battery amphour rating.
I used a Leece-Neville 120A unit with dual pulleys in addition to the standard alternator. The 120A unit is for the house batteries whilst the standard 50A unit is for the Starter battery.
All cables work through a dual battery switch with a VSR.
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