Mike Longcor (SV Trilogy)
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Hi Bill - do you mean that last section of exhaust looks modified/non-Amel or just generally speaking?
Ruslan - I like a shutoff valve because it absolutely solves the backflow problem. If I went that direction, I would prefer a basic (no switches or sensors) and non-metal part to eliminate corrosion. The only real problem, besides the hassle of installing it, is making sure it's open before starting the engine and as others have said, in an emergency it would not be good at all.
If anyone has any experience with the rubber non-return flap in the exhaust or anything similar please let me know. What does this thing look like?
If I could reach the exhaust from deck I'd probably go with the foam ball on a string method :) ...opportunity for a special tool here? Just kidding.
SV Trilogy - SM23
On Mon, Jan 27, 2020, 5:23 PM CW Bill Rouse <brouse@...
I think you will discover that SM 23 has been modified by previous owners.
Thanks James! I've looked into all of those things except the internals of the injection elbow. I'll definitely check that as soon as I can. I'll give the muffler a double check while I'm at it. I'll let you know if I find anything... seems like I'm swallowing more seawater than most here.
Now something I overlooked earlier... at the through hull there is a little over a foot of extra wide pipe/hose. I'll attach a photo and hope it comes through. Looking up the exhaust from the outside, it appears to be totally hollow. This must be where the non-return rubber flap should be installed as referenced by Oliver and others.
Does anyone have any experience in replacing this? Probably best to source this part from Amel? Although given my SM is 1990, so this specific modification might be non-Amel for me. Is it just held in place with some marine adhesive?
Any advice is welcome here. Haulout is scheduled soon so it would be an ideal time to fit something.
SV Trilogy - SM23
On Sun, Jan 26, 2020, 3:30 PM James Alton via Groups.Io <firstname.lastname@example.org
A few things that you might check on your exhaust system that could be the cause:
1. Check to be sure that the exhaust hose is looped as high as possible between the muffler and the discharge. Perhaps a previous owner used less hose and lowered the loop from the original design? In order for seawater to enter from the exhaust port it has to climb over this loop so the higher is better.
2. Insure that your muffler is working properly. Run the engine, shut down and then remove the exhaust hose to the muffler. I like to see the muffler less than 1/3 full due to the drain back from the exhaust hose. In order for the engine to flood from the exhaust port the muffler first has to fill with water. If the muffler has more water than this, you could have a problem inside the muffler that does not allow the engine to properly clear the muffler usually due to corrosion.
3. Engines can also flood from the seawater intake side of things. The line should be looped as high above the WL as practical and there should be a vent at the top of the loop that must function or seawater can be siphoned over the loop and into the engine. Insure that the vent is working properly.
4. Ensure that the seawater injection elbow normally located at the connection between the exhaust manifold and the exhaust hose is not corroded through.
My boat is a Maramu so our systems are probably somewhat different. I have removed the exhaust hose a few times after a rough passage and before starting the engine to see how much water had accumulated in the muffler and so far the level has always been nominal, or about the same as after shutting down the engine while dockside. I have therefore not been too concerned about running my engine on passage and have not had any water in the engine to date.
There are a number of low pressure check valves that you can install in the exhaust system to help prevent seawater from being driven in the exhaust port that you could look into but I suspect your problem is due to a faulty component or some change that has been made in the design of the exhaust system. Best of luck to you, seawater can sure do a lot of damage to your engine so I hope that you can find the cause and rectify it.
On Jan 25, 2020, at 4:56 PM, Ruslan Osmonov <rosmonov@...
Hi Mike and everyone, this is the page where Charles Doane explains what he did at the end to deal with his flooded engine on his Boreal 47.
His solution was a valve with electric switch to avoid accidental start with the valve closed.
I’m a potential buyer and would like to understand if such a solution applicable in Amel’s setup.
It would be great to eliminate one more worry to run an engine on a passage especially when seas are rough. Additionally when seas are rough diesel gunk can mix up and clog fuel filters, yet another problem to deal with.
Sorry to bring this topic up again, but I thought I should share our recent experiences on the issue...
We have experienced seawater backflow twice this year while on multiday passages in the South Pacific. The first time, we were unaware of Amel's suggestion to run the engine while sailing. The second time, armed with the knowledge that one should run the engine once a day, we had a crankcase full of seawater after 18 hours. It's now clear, as explained by Oliver, that under certain conditions, the running of the engine needs to happen more often.
Because we have a 1990 SM, there doesn't seem to be anything in the exhaust line to block/baffle/slow down sea water from backflowing toward the engine. We also have a stainless muffler without a drain. The old Perkins Prima M80T, still alive and well, may have survived simply by being old and worn, allowing the incompressible seawater to escape around the rings before bending any rods, blowing gaskets, or cracking the engine...?
At any rate, wouldn't the simplest solution be one that prevents seawater from entering the crankcase altogether? To me, the variables involved in deciding when and how often to run the engine are more complicated than something more bulletproof, like a valve. One has no way of knowing really how much seawater is being pushed up the exhaust in a given seaway. Let alone the fact that we are burning diesel for the sole purpose of producing exhaust gasses.
All that considered, I don't yet have an ideal solution. A muffler with a drain would probably cover it. Then depending on the passage, one can decide to pull the plug or to run the engine at certain intervals. For us, we will probably run the engine every couple of hours in a rough sea until I add a drain to the muffler or come up with something better. An engine full of seawater is a terrible thing to experience while making landfall after a long passage... I'm just grateful the engine survived and that we were carrying enough fresh oil.
If I do come up with a simple and "bulletproof" solution, I'll be sure to report back.
Mike & Hannah
On Mon, Jan 13, 2020, 9:10 AM CW Bill Rouse <brouse@...
Thanks, Scott. I agree completely
On Sun, Jan 12, 2020 at 2:46 AM Alan Leslie <s.v.elyse@...
Agree, seems quite a few of us are on the same pages on this KISS
Elyse SM 437