need help with proper vent routing for blower motor

[badbowtie]

I am going to replace my vent ducting on my 21' boat I have vents on both sides of the boat. Starboard side intake in and port side exit. since I have had the boat their has only been two hoses hooked up both on port side one that has the blower on it which pretty much lays in the bottom of the bilge and the other one has no blower and is about half way down the bilge. I am replacing them due to they are falling apart. I have some tubing already just trying to figure out the correct way before I start cutting.

 

[carcraze]

Re: proper vent routing for blower motor

Re: proper vent routing for blower motor

You may want to have a look at this thread as there is a post to a link refering to some venting regulations.

http://forums.iboats.com/showthread.php?t=397807

 

[badbowtie]

Re: proper vent routing for blower motor

Re: proper vent routing for blower motor

I have seen that thread and everyone is just talking about the right material I have the right stuff just looking for a diagram or some pictures of the correct way it should be. I will have to look through it some more maybe I missed it.

 

[badbowtie]

Re: need help with proper vent routing for blower motor

I am just looking for a couple pictures of the proper way to run them and how far to make them sit in the bilge. I am not sure I need tube hooked to the inlet ones since it just feeds the whole engine bay under the sundeck.

 

[carcraze]

Re: need help with proper vent routing for blower motor

This link as posted in the other thread, very last post refers to some positions required for the tubes.

http://ecfr.gpoaccess.gov/cgi/t/tex...=div6&view=text&node=33:2.0.1.8.45.11&idno=33

In my boat (has not been surveyd yet as I am still working on it) has the intake tubes plumbed to the back of the rear seat center and about carb base level.

The exhaust vents and inline blowers on mine are plumbed such that the blower line comes from the transom down into the bilge above the water area (hopefully) as gas is heavier than air. The second exit not on the inline blowers is engine carb height at the transom. My set up should yeild a nice cross flow. Sorry I do not have a picture.

Again mine has yet to be checked out so take it for what it is worth.

 

[Boatist]

Re: need help with proper vent routing for blower motor

It is really pretty simple.
Gas fumes are heaiver than air so they sink to the bottom of the blige.
So the exhaust hoses you you want as low in the bilge as possible without being so low that they could be covered by water.
They must be lower the any spark source on the engine.
One should have a bilge blower on it and a cowl faceing the stern. This one will be used with the bilge blower on before starting the engine. This is a good time to go back and siff the air for gas fumes.
The other should be the same except with no blower. This one will suck out more air than the one with the blower while driving down the road or running at speed out on the water.

On the other side you should normally have two more cowl faceing the Bow.
These are for air input. Many times these will have no hose on them.
Ideal is for them to have a hose to the engine area but higher than the Carburator.
It is the same Idea here to force the heaver than air gas fumes down to the bottom of the bilge where they will be sucked out.

By the way if you ever smell gas do not start the engine. Get everyone off the boat and then try and find the source of the smell.

I would suggest you take a Coast Guard Aux Boating Skills and SeamenShip class or a US Power Squadron class.
Both of these classes cover all the saftey gear in depth and well as rules of the road,
how to read charts, what the buoys mean, what sound signals you are required to give an what they mean, How to use VHF Marine radio for a Emergency or to contact the marine.

Classes are Cheap and fun and will make anyone who takes them a better boater even if you have been boating your entire life.

 

[oops!]

Re: need help with proper vent routing for blower motor

good post above....

the short story.....

place the blower on suck.....and the sucking hose in the bilge......yes...laying in the bilge or at least below the top of it.....connect the blow end of the blower to the outlett of your boat.

done.

DO NOT OVER THINK THIS.....IT IS REALLY SIMPLE.
the kid that first installed the blower assembly on your boat probably only made 5 bux an hour.
suck the gas fumes out of the blige....thats all.

cheers
oops

 

[badbowtie]

Re: need help with proper vent routing for blower motor

Thanks Boatist
That is what I was looking for I figured that was how to run them just wanted to make sure when you are dealing with explosion. I may still try to hook it all up tonight since we were supposed to go back out tomorrow but know they are saying storms for like the next 6 days.


The only boating course I have taken was the ohio boaters education course.
I will look around for some other good ones to take I will look at the two you recomended also. My local librabry has a water safety class next week that I am taking my 9 year old down to.

 

[25thmustang]

Re: need help with proper vent routing for blower motor

Your set up sounds good. The other side is not for a blower, but to allow air to leave the engine room. My boat has two blowers, and four vents letting air out.

 

[Boatist]

Re: need help with proper vent routing for blower motor

Badbowtie
One thing on Boating classes.
You can find classes on line and the courses are about the same but if you go to one of the classes you will find a mix of people. Some who have never even been on a boat to the old Salt who lived on the sea for 50 years.

You will learn from the questions other ask that you did not think of.
In the class will likely have several people who know the area and can tell you about danger zones to not get caught in.

An example would be just outside San Francisco Golden gate. This area can be very bad. Normal summer day the wind will be blowing in at 35 knots and if you also have a Ebb tide of 6 knots the waves will peak up and start breaking. If that not bad enough the water gets shallow in the 4 fatom bank. To pass in this area at the peak of the EBB tide is very dangerous. Many boats down in the area. Wait for the tide to slow or for the Flood tide and it is pretty safe. Still lots of fog and high volume of large ships that are actually in traffic lanes. Most ships will pick up a pilot to bring them thru the Gloden Gate.

That is the type of information you get in the class that is not in the books.

You will also here lots of stories both Funny and Sad and have to Tie a number of knots instead of seeing a picture in a book.

I said the Classes are cheap and they were but in some area now they are costing much more. In My area the Coast Guard aux charged $60 this year. This was for the boat, home work and class room. It seams that school and park districts use to donate class room but in these tough times some are now charging to help balance their budgets.

I have taken 5 classes and learned something in every one. I will say the longer classes 13 WEEKS and much better than the shorts classes.

Enjoy your boat and stay safe.