You can try an 12V automotive radiator fan mounted directly over the exhaust
vent. They last a long time, push alot of air, and are easy to replace.

I seen one boat with multiple computer fans. 4 or more small fans mounted on
a frame. If one fan dies, the rest keep going. Plus the fans cost $5 each at
any electronics surplus store.

Same princple applies to cheaply Air Conditioning a cabin.

The computer fans are mounted on a square frame.
2 reusable home air conditioning filters act as dust catchers for the front
and rear.
A very small water fountain or bilge pump circulates cold sea or fresh water
into a trickle copper tubing array.
The fans simply blow warm air into the array, and out comes nice cool air...

I can provide you a diagram if you like. You can alter the setup to suit
your needs.

Jim Rojas


"Wayne.B" wrote in message
...
On Mon, 24 May 2004 12:30:14 GMT, wrote:

I don't run the blowers at cruise, as the venturi effect is sufficient
to keep the bilge vented, but it's my "operating procedure," if you
will, to operate them while the generator is running, before start-up
of course, and while idling.

==================================

Nothing wrong with that, good practices in my opinion. You just need
to get a heavy duty blower, which as you have found out, does not
apply to the plastic inline models.

Another poster referred to the engines "drawing air out of the engine
room". That does happen to some extent since the engines draw in air
through the intake manifolds to support the cumbustion process.