I have not seen much in the way of double alternators on 4108's so I thought I would post the one I have seen and see what others have done.
I had seen a 4108 locally with the 2nd alt inline left with a simple bracket on an old 4108 (1st 3 foto's blue motor) but because I didnt have room on the side I made a bracket to mount it backwards on the front left.
The double pulley would cost 200 euro's online and a standard kost 5 euro's, so I bought the standard pulley and put it on a lathe and cut the inside out, then bolted it to the existing pulley. I then welded a bracket up to take the 70amp alt that I had left over from a previous boat, now I have 2x 70amp Alts charging
460amp house and 240amp start/ bowthruster batteries. I also have 370watts in solar panels
and regulary stay 3 days on anchor
with out running the motor
, the solar panels
handle the batteries running the inverter
to warm the water
up, charge the 2 latops, run the fridge and charge the phones. The motor
is for rainy days, because I want to take out the petrol driven 3.7kva genset to make room for the diesel
tank by moveing the battery
bank aft along with the diesel
tank which is on the side of the boat and makes us lean when empty.
other fotos from my first attempt, I had to put an extra arm behind the bracket to the holes onder the oil
pump to stop a vibration at 1600 revs, will add that foto later. The 2nd alternator
wasnt an earth free model like the standard 4108, so I made nylon bushes to keep it insulated from the motor.