"engsol" wrote in message
...
Intake-strainer-exchanger-pump-exhaust

Any problems I'm overlooking with this arrangement?


Two problems.

1) Usually, the raw water pump is mounted low on the engine which keeps the
"head" that it has to prime against to a minimum. In many boats the water
pump could actually be below water line which will assure that the pump will
prime. If you have to pull the water to the top of the heat exchanger it
will mean that the pump has to be capable of drawing water several feet
higher before it primes.

If the system has been totally drained, either from a small leak or perhaps
you removed a hose or similar maintenance item then the amount of dry
running the pump will need to do before it gets wet will increase
dramatically.


2) Even once the system does prime it is likely that it will produce far
less "vacuum" then it will pressure. You might experience a drastic drop in
flow rate doing it this way.

Rod McInnis