Thanks all for the answer
Weight is not a problem, it will be in a new
steel motorsailer 46 ft, 28.000 kgs, (56.000lbs)...
I found lighter diesel but all air cooled, it's very hard to find small water cooled diesel (any idea,
advice on brand? links?)
Mounted in the engine room, in the
bilge, no problem for space, but honestly i didn't thought about the heat from the exhaust manifold; for sure covered with heat protection and what if i connect it directly to the exhaust system of the main engine (dry exhaust, it would work),
About the
reliability, i've read that sometimes have problem on starting
motor, but for all the rest they are bulletproof, used for years no stop in small tractor in the farm in
china and all the
asia...it's 1 liter for 13 hp, low revving...Less sprinted than any heavy duty engine
For sure i will buy some resplacement
parts with the engine...
I would want it because i don't want to run the main engine, without pratically any load on it, maybe for a pair of hours every 2-3 days, if not more, just to recharge the battery with a bigger alternator...
The use would be full time
liveaboard, with everything, from
air conditioning, to induction coocking,
washing machine, wife's hair dryer

...
I already included 2x 400 watt
wind generator and 4 x 250 watt photovoltaic
panels; i don't want to waste diesel (especially here in
italy where is about 1,5 euro/liter, so no webasto) but for example during
winter when at 4 pm is dark and no
wind, you need a hot
shower, a warm place, than 2 seabass in the
oven (30 minutes at 2000watt;D)...Heat and energy in just one machine, especially to do not need to produce heat with electricity...
Thanks krillernoova,
8 x12 v 200 amp pb battery in parallel series, 24 v 800 amp at 19,2 kwh, with pure sine wave 230v ac
inverter..No problem even with 2 x 200 amp alternator...