"JAXAshby" wrote in message
...
note that a 2GM20f is **freshwater** cooled. a raw water cooled engine is
a
different breed of cat.


Most common marine water heaters are equipt with a copper or brass engine
water coil.. Therefore raw water shouldn't be circulated through it..

If a person wants to us raw water to heat domestic water, this coil should
be replace with something in CuNi.

However, most raw water cooled engine have a low temp thermosat and the
water temp may never get over 150 degree. Not very much of a rise for stored
hot water. A 6 gal tank wouldn't provide more than a couple showers. (the
main reason I want hot water).

Steve
s/v Good Intentions