How low into the bilge should blower tube go?

[JerseyBoater]

Hi all,

I read in a lot of places that the blower tube should go as low as possible into the bilge. I have a Maxum 1700 with 3.0L Mercruiser.

The blower tube effectively stops where the starter motor is, rather than going down under the engine, is that ok?

Thanks

 

[alldodge]

Re: How low into the bilge should blower tube go?

Hi all,

I read in a lot of places that the blower tube should go as low as possible into the bilge. I have a Maxum 1700 with 3.0L Mercruiser.

The blower tube effectively stops where the starter motor is, rather than going down under the engine, is that ok?

Thanks

A slight bit farther IMO is better but at the starter is fine.

 

[JustJason]

Re: How low into the bilge should blower tube go?

It should go all the way down to the bottom. The blower is more of a sucker, and you want it to suck gas fumes up and blow them outside of the boat. Imagine a wet/dry shop vac trying to pick up a piece of very very light tissue paper or cotton ball from just a foot away... It's not going to be able to do it.

 

[JerseyBoater]

Re: How low into the bilge should blower tube go?

JustJason your tagline is perfect in this case, "just because you found it that way... doesn't mean it's supposed to be that way."

The hose is at it's limit so will have to replace it to get it reach a bit more, looks like it also got a bit crushed by the steering ram higher up.

I know I can only assume they decided it "blew" out the boat, calling it a sucker would be much better!

 

[agallant80]

Re: How low into the bilge should blower tube go?

Mine goes under the block. Gas fumes go low.

 

[Bob_VT]

Re: How low into the bilge should blower tube go?

Opt for a different pick-up point. I don't like explosive fumes being dragged past the starter where there is a chance for spark or a glowing wire.

 

[alldodge]

Re: How low into the bilge should blower tube go?

Good thing air is lighter then a cotton ball or we couldn't breath it

 

[smokeonthewater]

Re: How low into the bilge should blower tube go?

It should go all the way down to the bottom.

Absolutely not


It should be routed to the lowest point in the bilge that is above any likely water level... If it is all the way at the bottom then only a few inches of water will block it and render the blower inoperative... a couple inches lower than the starter and within a foot of two of the bottom center is fine.... If the hose is damaged or brittle replace it.... also absolutely secure it along it's route.


The task of the blower system isn't to remove every possible cubic inch of gas fume.... Don't get me wrong, it does, but a tiny little pocket would go pop... an entire hull full would put you into orbit...... gas fumes are heavier than air and if the suction hose drops below the starter you are set up to remove the deadly condition that COULD otherwise exist without your knowledge

 

[Grandad]

Re: How low into the bilge should blower tube go?

I agree with smoke. The air movement caused by your ventilation system doesn't start and end at the end of the tube. In my honest opinion, if the end is a few inches above bilge water level, it will effectively remove any hazardous concentration of fumes. Once bilge water rises to the end of the tube, there is no more circulation. Anyway, that's where I've placed my bet on my family's safety. - Grandad

 

[H20Rat]

Re: How low into the bilge should blower tube go?

Imagine a wet/dry shop vac trying to pick up a piece of very very light tissue paper or cotton ball from just a foot away... It's not going to be able to do it.

Interesting but inaccurate analogy... Lets use cigarette smoke instead. Put the smoldering cigarette beside the cotton ball, and I bet the smoke makes a straight line towards the shop vac hose! Reality is that having the hose even with the starter is more than low enough, a 4" bilge blower moves A LOT of air. In fact, in many cases, it is better to have it in this location than to try and get it lower and possibly crimp the hose.