Originally Posted by wayne.b
A couple of questions: I'm curious to know why you wanted to avoid common rail engines? Also, when you say that you only need 180 hp, is that the calculated power to reach hull speed
? If so, I think I'd want a little extra reserve, especially if you also need to drive a refrigeration compressor
and high output alternator.
I have a lot of limitations in draft
both above and below the waterline which leaves me in the bluewater class of sailing. Common rail engines are run by computers
mostly and the software
is proprietary within the manufacturers specifications. The software
can be bootlegged, I know that, but I don't like that option. But back to the subject: In many cases when a fault is recognized by the computer, the system will shut down and it requires a certified factory mechanic
with the software to clear the fault. I chose not to deal with that issue. I wanted something that I might better service
myself with selected spare parts
on board when offshore
, and not limp into passes and ports
at 3 knot
until the fault could be cleared.
I agree on the extra HP for the compressor and alternator. The calculations came up to 180 HP for the boat and drive train, but the extra effort is covered with the 210 HP that I am installing. The compressor only needs to run about 90 minutes every 12 hours to drive down the temperatures in the Freezer
. The alternator is also a variable that I cannot calculate accurately until I record
the data. But I think I have enough to make hull
speed with all systems running.
In a flat water
situation and all systems charged, I am overpowered by 30 HP, but making 9.2 knots theoretic hull
speed. That calculates to 2600 RPM on a 2800 RPM engine.