Cruisers Forum

Join CruisersForum Today

Thread Tools Search this Thread Rate Thread Display Modes
Old 06-04-2008, 07:31   #1
Registered User

Join Date: Dec 2005
Posts: 8
Exhaust question

Our recently purchased catamaran has a single inboard engine in the center of the boat (aft view). The exhaust pipe ends about 8 inches below the water line. The engine is above the water line and we hope the boat never heels. In all that we read (Calder, etc.) the illustrations show the exhaust pipe ending above the water line. A local "expert" tells us that having the exhaust below the water line will create undue pressure on the engine and that there is the danger of a following sea causing water to flow up the exhaust pipe thereby flooding the engine. Our exhaust system does not have a muffler. Do we need to make modifications?

prout35 is offline   Reply With Quote
Old 06-04-2008, 10:07   #2
Registered User
island trader's Avatar

Join Date: Apr 2008
Location: charleston, sc
Boat: 46 island trader hull #1 1979, WILEY G
Posts: 28
Is there not a " riser" in the exhaust system, or does the exhust go straight down to the thru hull? there are lots of Prouts out there, I would think it's a good design.
island trader is offline   Reply With Quote
Old 06-04-2008, 11:08   #3
Senior Cruiser
delmarrey's Avatar

Cruisers Forum Supporter

Join Date: Mar 2003
Location: Blaine, WA
Boat: Boatless Now
Posts: 10,805
Images: 122
A couple inches below the waterline shouldn't hurt. It wouldn't be any worst then a wetlift.

Although, there should be a loop in your exhaust about 18" above the waterline before it exits the vessel. But then you then you would have go with a wetlift just to catch the returning water after a shut down.

Maybe a flapper on your exhaust port, like on powerboats, would be the best solution.

If the boat is heeling with the motor running, water will not enter.

Marine Hardware - 316 SS Generator Exhaust Ports or similar.

Faithful are the Wounds of a Friend, but the Kisses of the Enemy are Deceitful! ........
A nation of sheep breeds a government of wolves!

Unprepared boaters, end up as floatsum!.......
delmarrey is offline   Reply With Quote


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
Exhaust drh1965 Engines and Propulsion Systems 14 18-09-2007 07:33
Exhaust Location (Thruhull) SkiprJohn Construction, Maintenance & Refit 6 22-07-2006 12:59
New Exhaust Outlet seafox Construction, Maintenance & Refit 21 09-12-2005 14:45
Exhaust System Maintenance GordMay Engines and Propulsion Systems 9 02-12-2004 21:16

Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 16:32.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2018, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2018, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.