in addition, most raw water cooled engines don't have hot water coming out of
them anywhere, except sometimes between the cylinder and the exhaust manifold.

pumping raw water slightly warmed by the engine doesn't make for hot water in
the heater, and on some raw water cooled engines splitting the hot engine block
water away from its next point to the water heater and back to that point can
cause uneven engine cooling.

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