• Untitled Document

    Join us on March 29rd, 7pm EST

    for the CBEC Virtual Meeting

    All EYO members and followers are welcome to join the fun and get to know the guest speaker!

    See the link below for login credentials and join us!

    March Meeting Info

    (dismiss this notice by hitting 'X', upper right)

Dorade vent on E26

diogenes

Junior Member
Colleagues,
I’m a recent storm , I saw a substantial leak coming from the dorade vent . This boat is new to me . Is there a hose that should connect to it internally ? Mine right now is just a thru deck and water can get in and soak the liner (not good)IMG_5228.png
 

Loren Beach

O34 - Portland, OR
Senior Moderator
Blogs Author
There might be drips around the base plate fastenings, indicating a need to re-bed the base. I have not have that happen but did have some repeated drips around the plastic where the vent was friction fitted into the base, when it rained hard. I "solved" that by putting some softer silicone sealant around the base and rotating it a bit while pushing it into place. This sealed it OK, and it could still be removed by rotating it and then pulling it out.
 

diogenes

Junior Member
Looks like a simple cowl vent. You can put a bag over it against rain, or remove the cowl and close the opening with the screw plate.

If it's actually a Dorade box, yeah, there will be a drain system to check out.
You are correct , this is just a cowl vent. Since the bottom is covered by the liner , I doubt that provide much ventilation unless it was connected to the blower hose of the engine bay . No need here either since it is a doesel and not a gas atomic 4 . I might just close it with a plate.
 

diogenes

Junior Member
T
There might be drips around the base plate fastenings, indicating a need to re-bed the base. I have not have that happen but did have some repeated drips around the plastic where the vent was friction fitted into the base, when it rained hard. I "solved" that by putting some softer silicone sealant around the base and rotating it a bit while pushing it into place. This sealed it OK, and it could still be removed by rotating it and then pulling it out.
his is a great solution . How about water coming through the vent itself ? Do you have a dorade box underneath it ?
 

Christian Williams

E381 - Los Angeles
Senior Moderator
Blogs Author
The bottom covered by a liner? Should be an open hole from which heat can vacate. Or perhaps a hose from a blower?

I think it's good to have the ventilation simple cowls provide, even if in a rainstorm a bit of rain may get in.
 

KS Dave

Dastardly Villain
Blogs Author
Yes, that's a cowl vent that is/was hooked up to ventilation hose and the blower system. The starboard side cowl vent goes down into a hole behind the diesel tank, then routes down the port side under the quarter-berth to the blower fan (if still equipped) under the inspection port behind the battery box. The port side runs down the headliner above the quarter-berth then turns the corner and runs forward on top of the diesel tank and connects to a fitting just forward of the wet exhaust muffler.

Since @Roger Janeway has a pristine example of an E26, I included a picture of his. Mine leaked like a sieve and the wood was all rotted in between the two layers of glass. Also, my hoses were trashed and the fan was gone. I bought replacements and will probably hook it back up just for airflow, but it hasn't floated back up the list, yet.
I recommend pulling the trim rings out, mining out any soggy wood and filling in the void with thickened epoxy, then re-bedding as a start. I don't know what the others do, but I leave the vents off and have the caps in place most of the time. I've looked around and not sure if they make a 3" dorade that would work there; the space is kind of tight on the exterior and not easily accessible from the interior for adjustment purposes.

NoraJ_Exhaust-to-Cowl.jpg
 

Shankara

Member II
On my 1980 E25+ I was having a similar issue. The flimsy vent hose which previously ran rain water to the bilge was torn and leaking water all over stuff in my cockpit locker, and also sneaking into the cabin.

IMG_5429.jpeg

I bought new cowl vents, and for the drain hose I used some 4” single wall drain pipe from Home Depot: https://www.homedepot.com/p/Advance...Singlewall-Solid-Drain-Pipe-4540010/100212428

IMG_5428.jpeg
The drain pipe has a female end on one side that slipped perfectly over the bottom of the cowl vent base fitting.

I ran the pipes on either side down far enough to drain into the bilge without leaking where it should not.

The better option may be to add a small dorade box: https://www.fisheriessupply.com/vetus-denouden-dorade-boxes
 

Shankara

Member II
What is the purpose of a hose from a vent to the bilge?

Is there a blower?
2 reasons: Keep water from getting everything in the locker wet. Also, to keep water from running along the underside of the cockpit combing into the cabin and destroying wood work and upholstery.

I couldn’t afford the dorade box at the time.
 

Christian Williams

E381 - Los Angeles
Senior Moderator
Blogs Author
But what does it vent, without a blower? The long hose kills any passive circulation.

Just an observation, and opportunity to revise.
 

KS Dave

Dastardly Villain
Blogs Author
2 reasons: Keep water from getting everything in the locker wet. Also, to keep water from running along the underside of the cockpit combing into the cabin and destroying wood work and upholstery.
Removing the vent and putting a cap over it will accomplish the same thing (keeping water out) assuming you've addressed the leaky trim ring.

But what does it vent, without a blower? The long hose kills any passive circulation.
Without a blower, I agree.

To further address the point of having it, with a blower, the air "intake" is on the port side and the blower "exhaust" is starboard. Below is another picture with references. The blower is just on the other side of that bulkhead and the hoses from it run as I described before. Looking at different angles, the "intake" hose appears to be just dangling there behind the engine. I can't speak to effectiveness or even necessity, I'm simply trying to ascertain what the original design intention was. The old brochure said this "exceeds required specs".

NoraJ_Engine-Top.jpg

E26-Brochure_Engine.png
 
Last edited:

diogenes

Junior Member
Very good discussion! I am of the opinion that the vent accomplished very little since blowers are a necessity for gas powered inboard engines but not diesel. It seems like a redundancy that is very unecessary and does not improve the overall air circulation. I will just cap the vents and make sure the plates don't leak.
Thanks for all the opinions, pictures and suggestions.
 

Alan Gomes

Sustaining Partner
Very good discussion! I am of the opinion that the vent accomplished very little since blowers are a necessity for gas powered inboard engines but not diesel. It seems like a redundancy that is very unecessary and does not improve the overall air circulation. I will just cap the vents and make sure the plates don't leak.
Thanks for all the opinions, pictures and suggestions.
FWIW, I removed mine.
 

Kenneth K

1985 32-3, Puget Sound
Blogs Author
But what does it vent, without a blower? The long hose kills any passive circulation.
I'm no HVAC engineer, but I suspect the long hoses do not kill passive ventilation.

My dorade vent in the forward cabin vents air to two outlets, one in the head and one in the fwd cabin top. In even 5kt of wind, you can feel (by hand or by face) a steady flow of air into the cabin. This air must be "immediately" removed from elsewhere in the boat, or the cabin would become "pressurized" to the same pressure level as that of the air (wind) entering the dorade. The cowls (in addition to gaps around seat lockers, the companionway slider, etc) provide the means for this stale air to exit so fresh air can continue to enter the dorade. I think of it more in terms of "pressure" than "open airflow," so I don't think the hoses hamper that very much.

Further, I suspect the aerodynamic disturbance of even a few knots of wind around an aft-facing cowl vent provides just a wee bit of "suction" itself, and further enhances the air-exchange process. I wouldn't cover my cowl vents for an extended period of time.
 

Kenneth K

1985 32-3, Puget Sound
Blogs Author
Perhaps I should add that my perspective may be a little different from many others. If you're at a dock with AC power and you run fans, blowers, heaters, dehumidifiers, or the like, closing off a cowl vent or two may not matter so much.

But, I'm on a buoy and use nothing other than a few damp-rid buckets and the boat's passive ventilation system (one dorade and two cowl vents) to keep the boat fresh and dry throughout the rainy PNW winter. It's been mold-free and relatively dry for going on 7 years now.
 

RCsailfast

E35-3 Illinois
Have 2 on my boat. 1 supplies air to the engine area and the other hooked to a blower to suck out heat or fumes. We
had a bad smell in the cock pit locker and ended up finding a dead bird inside the blower exhaust hose. It got in through the the scoop. I keep the vent scoops off and the plates on when not in use after that. There is no drain or filter/ screen on either so the plates keep birds AND water out.
 
Top