The heat exchanger in your set up is the key. Simple raw water
systems like mine run way too cool for best diesel engine operation.

As described in my response to Tom's Atomic 4 cooling question down
below, I'm looking into a keel cooler to get the operating temperature
up.

I'm glad to hear that your engine does put out that much heat. That
means that the keel cooler setup, which would cost about the same as a
big inverter, would give me hot water in more reasonable time.

--

Roger Long



"Jeff" wrote in message
...
Roger Long wrote:

(It takes motoring half a day to do it with the waste heat alone
from my 20 hp diesel).

Something may be wrong with your setup, Roger. IIRC, you have a
very similar engine to my Yanmar 2GM20FC. I run the coolant through
an 11 gal heater, and it get quites hot in well under an hour, maybe
even 30 minutes. Actually for a few years the engine was running a
tad hot (180 degrees) but after cleaning out the heat exchanger its
normally at 165-170, which probably slows the heating a bit. Even
if all I do is run the engine for a little while to set an engine,
it usually heats enough for showers for the day. When I run for
charging, the engine never gets above 160, so in that case after an
hour run its still not quite as hot as when we're pushing hard.

If you had a large alternator (like my 110 Amp) then by putting a
large load on it you might be able to raise the engine temp enough
to heat the water faster!