Re: diagram of exhaust system?
Any of the maintenance manuals will show the cooling system diagram . . . and the exhaust is shown as part of that picture.
Check the stickies on the top of the forums for links to the manuals.
In a nutshell . . . the exhaust on a marine engine is kept cool(er) by having water flow around the exhaust manifold. This is different than an automotive engine, where the exhaust manifold is just exposed to the outside air. that is why marine exhaust manifolds are so big . . . they have a chamber for the exhaust to flow and then wrapped around that is a chamber for the cooling water to flow. The exhaust goes upwards at the start of its journey and then goes downward to exit the boat. At a point where the exhaust starts to travel downward, the water and exhaust join in the same 'pipe' and mix together to further cool the exhaust.
