Main engine vent covers

[Big Chief]

In purchasing a 67’ cockpit MY, my surveyor suggested that when the vessel is resting in its slip to cover from the inside of the engine room the vents on each side. He suggested it is like storing your vehicles in your garage with the roll up doors always open; that allows dust and other similar airborne debris and moisture into the engine room. I could cover using a 2.5” x 7’ tarp that would be easy to remove before starting an engine. Any thoughts?jh

 

[SEVEN]

I have a wood frame that I attach a fine mesh screen to. It prevents the winds from blowing in. You could do the same and just staples plastic tarp to it.

 

[SEVEN]

BTW mine is mounted in the inside of the boat and sits on top of the airbox.

 

[jmooney]

I use canvas panels that snap in place on the inside of the intakes.

 

[bostonhatteras]

Curious where that fell in the surveyors list of necessary tasks ?

 

[Scarlett]

I use a piece of 3/4 inch foam insulation cut to fit on top of the air box. Light weight and easy to remove when starting the engines. Kind of like Seven’s set up

 

[bigbill]

i did the same as seven said with the wood frame with ss wire mesh on it, i also did as scarlett said and mad insulation board covers that sit on top of the wood frame. i mostly use them during the off season/winter

 

[Big Chief]

Boston Hatteras- it was not included in the survey; just a suggestion as I watched him during survey and discussing his findings and notes about what he saw.All, thanks for the responses on how you address the open vent issue!jh

 

[dottieshusband]

IMHO, this a practical way to go... 3 inch foam with zip on covers (sublimation printed with boat name)

 

[Big Chief]

DotiesHusband- I see you one top corner attached with line; are the covers pushed into the openings? Any Velcro holding in place? What do you by using “zip”?

 

[brettportzer]

I notice the newer boats don’t have the louvers like my ‘72 does.

Does anyone know why that is?

 

[dottieshusband]

The foam is 3 inches thick and cut slightly oversize and is simply compression fit into the vent opening. The cord you see is just a safety teather tied to the vent cover and fender track. The covers are made of a canvas fabric with a zipper surround to enclose the foam... if you Google Sailrite Box Cushion, there is a video of how to do it.

 

[bostonhatteras]

I notice the newer boats don’t have the louvers like my ‘72 does.

Does anyone know why that is?

Imo it's because the louvers are damage prone, require lots of holes drilled for rivets and the way they were installed with one side facing the air stream and one opposed the forward facing catches a lot of salt misted air or literal sea water. Thats my experience anyway.

 

[brettportzer]

Imo it's because the louvers are damage prone, require lots of holes drilled for rivets and the way they were installed with one side facing the air stream and one opposed the forward facing catches a lot of salt misted air or literal sea water. Thats my experience anyway.

I wonder if the design is different in a significant way, or could I just remove the louvers...

 

[Big Chief]

Thanks, Dotieshusband for the reply. I just placed a foam mat, 3' x 7 ' by 3/4" thick over both internal vents; really made a difference keeping humid air entering both engine rooms and keeping the damp cold out of the hallway leading to captain's quarters.
jh

 

[bostonhatteras]

I wonder if the design is different in a significant way, or could I just remove the louvers...

I think yours and mine are very similar, a big recess rectangle and a number of oval inlets above on the unseen top area. mine also had vinyl helix flex duct from three of the oval inlets that led around the ER. You can see how I modified mine in a recent post I made but what I didn't show was how I deleted the flex duct. I closed all the holes in the sole between the ER and the area behind the salon side paneling then cut a hole in the sole under the ER hull side vent and braced that with epoxied in 2x4 fir all around to not lose structural rigidity in the sole. From these 2x4 fir I attached 3/8 marine ply to create an enclosed box up to the underside of the gunnel deck and foamed the 1/4" top seam under gunnel. The opening in the sole also has 3/8 ply extending down into the ER about 4" lower than the overhead. This is where all my ER air enters and I place furnace filter media across the opening to catch any salt. The filter media is stapled which is kind of bogus but until I do something more elegant it works to keep the salt out. Without all the flex ducting the ER is really opened up. In the photos I posted, the long side of the box enclosing the ER vent is out and I created it to be removable if Justin Case needs access.

 

[jim rosenthal]

Brett, you could remove the louvers. You'd have a lot of holes to fill, but it would affect anything else, I don't think.

The louvers sometimes catch things and break, and the original design, which had one set facing forward and one set facing aft, didn't get any additional air into the engine room over what the engines would pull in. Hatteras revised the design and eliminated the vertical louvers in favor of a cleaner and simpler design.

 

[bostonhatteras]

Brett, you could remove the louvers. You'd have a lot of holes to fill, but it would affect anything else, I don't think.

The louvers sometimes catch things and break, and the original design, which had one set facing forward and one set facing aft, didn't get any additional air into the engine room over what the engines would pull in. Hatteras revised the design and eliminated the vertical louvers in favor of a cleaner and simpler design.

If Brett's are like mine were, there is a giant hole on the top, maybe 13"x3", which at one point was covered in bronze screen but long ago rotted. the gaping hole would pose an issue just left exposed. It would allow sea water to splash into area behind salon panels

 

[Scarlett]

Sams sells a material to use in place of that bronze screen. I think it is fiberglass, looks like cotton candy. I bought some and made a frame to put it on top of the air intake box.