In August, on the occasion of detecting water in the engine, I
critically looked at the exhaust of my MD6A.
It turned out that the water was coming through the leaking seals of
the water pump shaft, and the problem had nothing to do with the exhaust
- it was properly diagnosed at this mailing list, and I could fix the leak.
Anyway, since then, I think this exhaust is poorly designed, see:
http://www.albinvega.pl/wp-content/gallery/techniczne/lotta_exhaust.jpg
There are 3 problems, which may lead to water getting back to the engine:
- the point where water mixes with gases is too high;
- the silencer should be located at the same side of the boat as the
exhaust manifold. As it is now, if the boat strongly heels to starboard,
the silencer may end up higher than the exhaust manifold, and water may
surge back to the engine.
- there is no siphon break at the raw water injection line.
So now I wonder if I should do anything about it.
If so, how I should fix it.
Seems to me that I should modify the exhaust elbow to lower the
water-gas mixing point (or get a new exhaust elbow), move the silencer
to starboard, and mount a siphon break in the water injection line. Any
comments/suggestions to that ?
On the other hand, I have this exhaust for 7 years, and I have never
noticed any problem with it (and strong heels, waves, have not at all
been unusual)
Marcin
V1958 "Lotta"
critically looked at the exhaust of my MD6A.
It turned out that the water was coming through the leaking seals of
the water pump shaft, and the problem had nothing to do with the exhaust
- it was properly diagnosed at this mailing list, and I could fix the leak.
Anyway, since then, I think this exhaust is poorly designed, see:
http://www.albinvega.pl/wp-content/gallery/techniczne/lotta_exhaust.jpg
There are 3 problems, which may lead to water getting back to the engine:
- the point where water mixes with gases is too high;
- the silencer should be located at the same side of the boat as the
exhaust manifold. As it is now, if the boat strongly heels to starboard,
the silencer may end up higher than the exhaust manifold, and water may
surge back to the engine.
- there is no siphon break at the raw water injection line.
So now I wonder if I should do anything about it.
If so, how I should fix it.
Seems to me that I should modify the exhaust elbow to lower the
water-gas mixing point (or get a new exhaust elbow), move the silencer
to starboard, and mount a siphon break in the water injection line. Any
comments/suggestions to that ?
On the other hand, I have this exhaust for 7 years, and I have never
noticed any problem with it (and strong heels, waves, have not at all
been unusual)
Marcin
V1958 "Lotta"