Bilge Blower install help

[Destroyer]

Originally Posted by smokeonthewater

put a blower in it and operate it for several minutes before starting and while at idle or no wake speed.

the intake should go to the lowest part of the bilge NOT likely to have standing water... definitely below the starter.

as for fuel injection or carb makes no difference... fuel lines filters fill hoses vents and even tanks can leak..... heck the fuel tanks are a COMMON issue with these boats

Totally agree, which is why I said

Originally Posted by Destroyer

Baring leaks in your fuel system, at which point you should NEVER take your boat out on the water

Gas tanks are part of the fuel system. My point about the carbs vs Fuel injection though was that with fuel injection, unlike a carb, there is no fuel exposed to the outside (bilge area) air, which, in turn, means less likelyhood of vapor in your bilge area.

Originally Posted by macojoe

my 75 had them on top of the gunnels, one backward one forward, but no worry about water that far up!

Exactly correct. Your vents are mounted on the top of the gunnels. If you get water into your boat through them that will be the least of your problems. Your bilge pump will easily handle any spray that might come through them.

Originally Posted by rscottdds

Both of the vents on this boat face backwards. My bass boat has one forward and one backward. The v20 will be an ocean boat though and I think I'd rather keep them facing the way they do so salt water spray doesn't get channeled into the engine compartment.

The way this boat will be used it will be started multiple times a day and the thought of lifting the engine hatch each and every time just doesn't appeal to me. I've seen a few pictures of what can happen when there is an explosion. Not a pretty site. If we are going to put one in now is the time as I can't use the boat anyway.

Of course the first I/O my family had when I was young didn't have a blower (not sure any boats did back then) and it didn't blow up. Easily could have though as I did have an uncle pump 30 gallons into the bilge through a rod holder once.

The previous owner obviously mounted the vents wrong. With both of them facing rearward they are almost totally useless since the incoming air needs the forward facing vent to scoop the air into the bilge area.
Since my boat was constantly being run/trolled the only time I lifted the engine hatch was during trailering. By all means, if you want to install a bilge blower, then do so. An ounce of prevention, as they say.....

And as to your uncle pumping 30 gallons into the bilge thru a rod holder, it's really amazing how many stories like that we hear of. And truthfully, in that situation, the best bilge blower in the world won't help you at all.

[smokeonthewater]

you also said people would disagree with you... lol ... you were right BUT I do see your point about the carb vs FI AND I totally agree that you should never knowingly operate a boat with a fuel leak but sometimes you don't know... IE the first pin hole in an aluminum fuel tank... sometimes people don't find the leak till they see a sheen on the water from the bilge pump discharge....

I'll add though that since the FI runs at a higher pressure and that it uses an electric pump one MIGHT argue that it introduces a new risk all it's own... Also the O/P doesn't have FI anyhow

all in all I feel that the chances of catastrophe are very low and I often start the engines without running the bilge blowers if they haven't been off long and when I trailer to the ramp I figure that cruising down the road will ventilate the bilge just as well as cruising up the river... BUT I also have a fume detector I installed with an alarm and the ability to automatically activate the blowers at IIRC 10% of the LEL

[Rscottdds]

As far as the directions of the vents, I wasn't concerned with water pouring into the bilge but just some spray dripping into the engine compartment. I figured it was best to keep as much salt water out as possible even if it were just a small amount.

I can see the point about it ventilating the bilge very well on the way to the ramp when one vent is facing forward but when running out on the water the engine will clear the bilge better than any vent.

I'll probably turn one of them around and add a blower.

[smokeonthewater]

the engine will NOT "clear the bilge"..... that is why you are supposed to run the blower when operating at low speed. at higher speed it is the outside air flowing over the vent ventilates the bilge

[Destroyer]

Originally Posted by smokeonthewater

the engine will NOT "clear the bilge"..... that is why you are supposed to run the blower when operating at low speed. at higher speed it is the outside air flowing over the vent ventilates the bilge

100% correct.

(And Smokes previous comment about having a fume detector in his bilge area should also be taken to heart. It's cheap insurance, and just another layer of safety, along with the blower and the vents). As I said earlier..an ounce of prevention......

[garbubba]

I've seen a few go boom myself, always pays to be careful.

I think you have the plan by turning one around, if you tie down the hose from the intake somewhere near the bilge (above any water) any water will just go in there.

Putting the blower in the exhaust side saves it from that salt though, & which is great, because they don't like salt-water.

I'm glad my V has an outboard, blowers are a pain.

[smokeonthewater]

do NOT put the engine's intake in the bottom of the bilge... very bad idea... if you ever take a wave over the top and get water in the bilge your engine will die.... if you have a backfire you will channel it directly to the most likely place to have fumes

the blower ALWAYS goes on the exhaust side and needs it's intake hose routed to the bilge above likely water level... IE 6" above lowest point... intake need only be routed to the engine compartment but not down low so as not to stir up and oxygenate any possible fumes