Trojan Boat Forum

bigralph wrote:Quick question - I replaced my missing port side 3" blower yesterday. The 4" original on stbd still works. The original port was missing. I oriented the in-line blower to suck and now I have both port and stbd sucking from bilge. Was just wondering if the smaller fan, the port one I replaced, should acutally be a blower, pushing fresh air into the bilge.
Thanks.

Both blowers should be acting as exhaust - fresh air will be drawn in through the vents when the blowers are run. When the boat is moving fast enough the blower should not be needed (beyond idle speeds, or maybe beyond 1500rpm) - there should be enough airflow across the vents to ventilate the bilge.

I agree.

One blower motor sucks the fummy air from the the front and the other from the rear.

Gotta remember trojans have big side vents which do their job ie vent!

I took the blower back to Arizona with me to a local alternator repair shop that works on marine gear also. They took the motor apart and lubricated the bushings. They said that there are no lube ports and that the bushings are not replaceable so if it does not continue to work, I will have to replace the motor. I have not tried powering it yet, but it sure feels nice when I spin it by hand. Previously it made a lot of noise when spun by hand. Only time will tell...

while blowers are exhausting existing air from the compartment

Since gasoline fumes are heavier than air, sucking from down low will do a much better job of removing the fumes than blowing.

See also:

http://www.boatingsafety.com/boats/cgvent.htm