Lets talk vents

[Eliminator21vdrive]

So the barge has an appointment with Pedro and am re-thinking vents and how many and where.

So originally it had one up by fill neck and one towards transom on gunwale I am thinking of taking out the two near the caps and possibly moving the other two to upper transom?

Whats legal?

 

[BingerFang]

Are you having issues now? If no, why mess with it?

 

[Eliminator21vdrive]

Are you having issues now? If no, why mess with it?

Pure esthetics

 

[BingerFang]

Pure esthetics

Does your boat have a bilge blower?

 

[Eliminator21vdrive]

yep

 

[Rayson1971]

Can't figure how to load it but on Amazon they have 316 stainless round flush mounted vents that look pretty good. You might be able to use existing round hole

 

[BingerFang]

yep

I would imagine you need some type of intake and exhaust to vent the engine compartment that is full of fuel fumes. By removing the intakes you won’t be getting any fresh air inside the engine compartment. I’m sure someone with way more knowledge will chime in though.

 

[DarkHorseRacing]

As long as you have vents in the engine compartment somewhere, and a bilge blower that can force air drawn from the bilge out, and should therefore suck fresh air into the compartment, I think that’s what you need to comply with coast guard.

However I will say that I prefer the vents on the gunwales over the vents on the transom as the vents on the transom are more prone to intake water.

If you don’t like the old school vents there are other options that use the same holes that might look more modern (like the scoop type).

 

[Eliminator21vdrive]

As long as you have vents in the engine compartment somewhere, and a bilge blower that can force air drawn from the bilge out, and should therefore suck fresh air into the compartment, I think that’s what you need to comply with coast guard.

However I will say that I prefer the vents on the gunwales over the vents on the transom as the vents on the transom are more prone to intake water.

If you don’t like the old school vents there are other options that use the same holes that might look more modern (like the scoop type).

Brother I am not stupid ! I understand the concept "as built"

 

[BoatCop]

Remember that the vents are part of a "system" to remove potential explosive vapors from the boat. There are (usually) two intake vents and 2 exhaust vents. The intake vents should have the hoses/ducts (minimum 3" diameter) long enough to be in the lower 1/3 of the bilge (or fuel compartment, if they're not the same). The exhaust hose(s) should be long enough to extend to approx the same plane as the engine carburetor, or about to the upper 1/3 of the compartment. The power blower (actually a sucker), if installed, should be installed in the exhaust hose and NOT in the intake hose. Ensure the blower is installed to blow OUT of the compartment and not INTO it. If you have a "scoop" (clam-shell) type cowl, the intake cowl should face forward, the exhaust cowl should face astern.

The system works by introducing fresh air into the lower part of the bilge to upset any gas fumes in the bottom of the boat, while siphoning the air/fuel mix out the rear of the boat. As designed, the boat moving forward "forces" air through the intake cowl(s) and into engine/fuel compartment, while the rear facing exhaust hose/cowl creates a venturi effect, pulling the contaminated air out to the atmosphere. With the boat stationary, the system does not work efficiently, which is why it's recommended to operate the blower when the engine is running, but boat is not in motion, or at slow (idle) speed. Don't operate the blower at speeds above idle, as it will actually interfere with the proper air flow through the system.

Make sure that the hoses are not kinked, blocked or otherwise obstructed. Depending on where and how your boat is stored, birds, rats, mice, etc, just LOVE building nests in those hoses.

FUELING: The blower, and any other electrical components, should be OFF, and any cabin/engine doors/hatches should be closed when actually fueling. After fueling, open the doors/hatches and the engine compartment(s) and sniff for any fuel vapors. If none, operate the blower and close what needs to be closed. At least 5 minutes is the recommended time to operate the blower before starting the engine(s).

Hopefully the ventilation system was designed by the manufacturer's engineers to provide for the most air possible to flow through the system to remove potentially explosive fumes and provide sufficient air to the engine. This takes into account, the size of the compartment(s), size and placement of the cowls and hoses, and even engine/carb/supercharger CFM. Changing the layout could degrade the effectiveness of the system, and potentially turn your boat into a bomb.

 

[DarkHorseRacing]

Remember that the vents are part of a "system" to remove potential explosive vapors from the boat. There are (usually) two intake vents and 2 exhaust vents. The intake vents should have the hoses/ducts (minimum 3" diameter) long enough to be in the lower 1/3 of the bilge (or fuel compartment, if they're not the same). The exhaust hose(s) should be long enough to extend to approx the same plane as the engine carburetor, or about to the upper 1/3 of the compartment. The power blower (actually a sucker), if installed, should be installed in the exhaust hose and NOT in the intake hose. Ensure the blower is installed to blow OUT of the compartment and not INTO it. If you have a "scoop" (clam-shell) type cowl, the intake cowl should face forward, the exhaust cowl should face astern.

The system works by introducing fresh air into the lower part of the bilge to upset any gas fumes in the bottom of the boat, while siphoning the air/fuel mix out the rear of the boat. As designed, the boat moving forward "forces" air through the intake cowl(s) and into engine/fuel compartment, while the rear facing exhaust hose/cowl creates a venturi effect, pulling the contaminated air out to the atmosphere. With the boat stationary, the system does not work efficiently, which is why it's recommended to operate the blower when the engine is running, but boat is not in motion, or at slow (idle) speed. Don't operate the blower at speeds above idle, as it will actually interfere with the proper air flow through the system.

Make sure that the hoses are not kinked, blocked or otherwise obstructed. Depending on where and how your boat is stored, birds, rats, mice, etc, just LOVE building nests in those hoses.

FUELING: The blower, and any other electrical components, should be OFF, and any cabin/engine doors/hatches should be closed when actually fueling. After fueling, open the doors/hatches and the engine compartment(s) and sniff for any fuel vapors. If none, operate the blower and close what needs to be closed. At least 5 minutes is the recommended time to operate the blower before starting the engine(s).

Hopefully the ventilation system was designed by the manufacturer's engineers to provide for the most air possible to flow through the system to remove potentially explosive fumes and provide sufficient air to the engine. This takes into account, the size of the compartment(s), size and placement of the cowls and hoses, and even engine/carb/supercharger CFM. Changing the layout could degrade the effectiveness of the system, and potentially turn your boat into a bomb.

I’ve never seen the exhaust hoses up by the carb, they are always shoved down into the bilge. Aren’t gas fumes heavier than air? Or is the logic that the starter is down there and that’s the primary source of a spark?

Also most boats I’ve seen the intakes are just vents, not hoses leading somewhere.

 

[02HoWaRd26]

Only you know the ultimate look you’re looking for, but here’s some vents that will help create more ideas as you get closer. Also talk to Pedro he’s pretty good at ideas and making things work.

Vent Plates - Marine Industries West

Marine Industries West, Dana Marine, Dana Marine Products, Dana Marine Parts, Dana Marine Billet Parts, Dana Marine Billet Hardware, Boat Billet

www.marineindustrieswest.com

 

[Eliminator21vdrive]

Remember that the vents are part of a "system" to remove potential explosive vapors from the boat. There are (usually) two intake vents and 2 exhaust vents. The intake vents should have the hoses/ducts (minimum 3" diameter) long enough to be in the lower 1/3 of the bilge (or fuel compartment, if they're not the same). The exhaust hose(s) should be long enough to extend to approx the same plane as the engine carburetor, or about to the upper 1/3 of the compartment. The power blower (actually a sucker), if installed, should be installed in the exhaust hose and NOT in the intake hose. Ensure the blower is installed to blow OUT of the compartment and not INTO it. If you have a "scoop" (clam-shell) type cowl, the intake cowl should face forward, the exhaust cowl should face astern.

The system works by introducing fresh air into the lower part of the bilge to upset any gas fumes in the bottom of the boat, while siphoning the air/fuel mix out the rear of the boat. As designed, the boat moving forward "forces" air through the intake cowl(s) and into engine/fuel compartment, while the rear facing exhaust hose/cowl creates a venturi effect, pulling the contaminated air out to the atmosphere. With the boat stationary, the system does not work efficiently, which is why it's recommended to operate the blower when the engine is running, but boat is not in motion, or at slow (idle) speed. Don't operate the blower at speeds above idle, as it will actually interfere with the proper air flow through the system.

Make sure that the hoses are not kinked, blocked or otherwise obstructed. Depending on where and how your boat is stored, birds, rats, mice, etc, just LOVE building nests in those hoses.

FUELING: The blower, and any other electrical components, should be OFF, and any cabin/engine doors/hatches should be closed when actually fueling. After fueling, open the doors/hatches and the engine compartment(s) and sniff for any fuel vapors. If none, operate the blower and close what needs to be closed. At least 5 minutes is the recommended time to operate the blower before starting the engine(s).

Hopefully the ventilation system was designed by the manufacturer's engineers to provide for the most air possible to flow through the system to remove potentially explosive fumes and provide sufficient air to the engine. This takes into account, the size of the compartment(s), size and placement of the cowls and hoses, and even engine/carb/supercharger CFM. Changing the layout could degrade the effectiveness of the system, and potentially turn your boat into a bomb.

I am fully aware of the design and function

 

[mattyc]

So the barge has an appointment with Pedro and am re-thinking vents and how many and where.

So originally it had one up by fill neck and one towards transom on gunwale I am thinking of taking out the two near the caps and possibly moving the other two to upper transom?

Whats legal?

View attachment 1370141 View attachment 1370141

I wont speak for " legal", but, as someone else said, as long as you have a fresh air intake and an outlet attached to a blower you're good. After that, its just a matter of the look you're after.

Also, are the forward vents a fuel tank vent? And rears are bilge vent?

If you dont see something available that turns you on, make em!!