Sundowner 30 What is this vent for??

[man7sell]

I am going to replace the cowl on this vent as it is old and sticky to touch. I replace 4 on my now sold sailboat with some nice stainless steel ones.


But where does this vent go. It is not in the forward cabin. It appears to go behind cabinetry. Maybe leads down to the engine room. Anyone know for sure?

[man7sell]

This cowl vent has degraded to a sticky and ugly vent so off it comes. Good job too because the deck plate it attaches to was just screwed to the top surface fiberglass exposing the balsa core to the elements. After resizing the hole, I dug out the soft balsa and filled it in to seal it. The new vent then installed with a good coat of 4200. And the finished cowl looks way better.



It is the engine room intake vent.

[Max1]

It probably goes to the engine room.
My boat has 4 louvers on the outside cabin walls, 2 in the front and 2 at the rear.
Inside, there are airboxes that lead outside air coming in through the lovers into the engine compartment.
It is naturally aspirated, so I assume the intent was to have fresh air come in via the front louvers and exhausts from the rear louvers. I don't think it worked very well for me as I would always get engine stink in the cabin after a run. I added an engine room blower to suck air out of the engine room. I turn on the blower when I start my engine and leave it on till at least an hour after I shut off the engine. It works for me.

Your configuration looks like it would have better airflow than just louvers since the air would be rammed in from the front intake when underway. Which begs the question- how does air exit your engine room?

[man7sell]

Originally Posted by Max1

It probably goes to the engine room.
My boat has 4 louvers on the outside cabin walls, 2 in the front and 2 at the rear.
Inside, there are airboxes that lead outside air coming in through the lovers into the engine compartment.
It is naturally aspirated, so I assume the intent was to have fresh air come in via the front louvers and exhausts from the rear louvers. I don't think it worked very well for me as I would always get engine stink in the cabin after a run. I added an engine room blower to suck air out of the engine room. I turn on the blower when I start my engine and leave it on till at least an hour after I shut off the engine. It works for me.

Your configuration looks like it would have better airflow than just louvers since the air would be rammed in from the front intake when underway. Which begs the question- how does air exit your engine room?

Yes goes to the engine room, Engine room air exits through a SS louvered vent on the opposite side of the boat. I need to install a blower for the engine room, like the idea of running it after the engine shutdown.

[Unclematt]

I have a 32 Sundowner, on mine that is the engine room vent. Mine has a fan to help exit the hot air.

[man7sell]

Originally Posted by Unclematt

I have a 32 Sundowner, on mine that is the engine room vent. Mine has a fan to help exit the hot air.

Yes a need a vent fan

[Max1]

Originally Posted by Unclematt

I have a 32 Sundowner, on mine that is the engine room vent. Mine has a fan to help exit the hot air.

That would work!