76SeaRay
Lieutenant Junior Grade
- Joined
- Aug 24, 2017
- Messages
- 1,071
So, when I got this boat in really ragged shape, the vent duct was rotted out and mostly missing. The boat as starboard and port vents 16 inches long by 1 inch high at 44 inches forward of the transom and both louver vents are forward facing as intakes. The intakes are pointing out to the side with a teak wood step covering them to prevent stepping on them an crushing them so they don't stick above the gunwale. The center of the transom has a single 20 inch long by 1 inch high vent pointing directly aft so would be an exhaust. A non-functional blower was kind of hanging at the transom opening (gone now).
So, it is pretty clear that I need a blower mounted at the center top of the transom under the gunwale with a single hose going to the bilge in between the inner transom plate and rear of the engine. The question is where to end the two side vent ducts. The boat had some old vent tube running from each intake vent under the gunwale back to the top of the transom and then dropped down through the "equipment shelf" to the floor. From there they were gone, rotted away... So, I plan to follow that path and add back in missing duct to get to the dog house area.
Now the questions, I can route the intake duct the way it was back to the transom and then to the dog house but where does the engine bay end of the fresh air duct get placed? I would think you would not want the fresh air duct dropping down right next to the blower intake since the blower would not be as efficient at pulling fumes out of the engine bay, that is, there would be a partial tendency to pull air out of the fresh air intakes instead. Has anyone used rigid duct to channel the fresh air to the front of the engine or do you just "point" the open end of the fresh air duct towards the front of the dog house? I don't remember seeing any vents in the dog house on other boats that I have been in....
So, it is pretty clear that I need a blower mounted at the center top of the transom under the gunwale with a single hose going to the bilge in between the inner transom plate and rear of the engine. The question is where to end the two side vent ducts. The boat had some old vent tube running from each intake vent under the gunwale back to the top of the transom and then dropped down through the "equipment shelf" to the floor. From there they were gone, rotted away... So, I plan to follow that path and add back in missing duct to get to the dog house area.
Now the questions, I can route the intake duct the way it was back to the transom and then to the dog house but where does the engine bay end of the fresh air duct get placed? I would think you would not want the fresh air duct dropping down right next to the blower intake since the blower would not be as efficient at pulling fumes out of the engine bay, that is, there would be a partial tendency to pull air out of the fresh air intakes instead. Has anyone used rigid duct to channel the fresh air to the front of the engine or do you just "point" the open end of the fresh air duct towards the front of the dog house? I don't remember seeing any vents in the dog house on other boats that I have been in....