That's a good point about the exhaust ... never really appreciated that
before ... since the water's there to cool the exhaust, might as well pump
it into the engine cooling system (unless it's a closed system but that
still requires a heat exchanger). Yeah ... can you imagine the safety issues
with a dry exhaust system on a pleasure craft ... yikes. Although, for
cooking up that fish dinner ... nah, forget it.

Harry Krause wrote in message
...
Paul Schilter wrote:

Since external water used in cooling engines causes a lot of problems,
why
hasn't a car type radiator system with fan ever been used?
Paul




Probably because it is difficult to get enough airflow to a radiator.
There's also the problem of the exhaust. Dry stacks are noisy, smelly,
and throw off a lot of heat in the boat's interior.

But there are closed cooling systems...look up "keel cooling."