I Heart Exhaust Elbows

It has been a week and we’ve written nary a word on our exhaust system woes. Lest our regular readers start to worry that we just chucked the whole engine in the dustbin and fitted Galapagos with a Yuloh, worry not! We have our top men working on a solution even as I type.

This is the exhaust riser after our September trip to the San Juans and Gulf Islands

Exhaust Elbow design #3  The weld failed totally as we docked the boat in Tacoma after a two week trip. Total engine hours: 148.

I’ll spare you a comprehensive history of the various exhaust risers we have had on the boat. But new readers may want to catch up by reading Engine Exhaust(ing) Episode 254 and Counting and Exhaust Elbow Blues, Reprise

Fortunately for us, our readership includes more than a few experienced engineers that have generously applied their talents to various projects on the boat. In this case, Steve Hulsizer commented more than once on the problems and issues we have faced with our exhaust riser. Offline, we corresponded and agreed to meet down at Galapagos this past weekend.

The back of Steve’s head as he examines the current riser.

Steve and Elsie Hulsizer are an interesting couple. They are veteran sailors, having cruised the east and west coasts of the U.S. in a variety of boats, most notably, a 32 foot Chesapeake sloop from Boston to Seattle via the Panama Canal. Their current boat is a beautiful Navy 44, Osprey, which they have taken to Alaska five times. Melissa and I were fortunate enough to attend a short rigging class conducted by none other than Brion Toss and held on Osprey a couple of years ago.

In addition to their extensive sailing resume, Elsie is an environmental professional and the author of two books on cruising our Northwest waters. Check out her work on Amazon. And, most important to our present narrative, Steve is a Professional Engineer with over 300,000 sea miles under his keel as a U.S. Naval officer and in the commercial fisheries and Norwegian Merchant Marine Service. He has designed exhaust systems for ferries, submarines and destroyers. Surely, this man can help us figure out a bullet proof, reliable and safe exhaust system for Galapagos.

So, what does Steve have to say about our exhaust system? He is recommending that we install a horizontal expansion joint (or exhaust bellows) as close to the manfold as space will allow. Then a vertical run with another expansion joint up about a foot above the resting waterline before making a 180 degree turn down. At this point we would add the water injection port before running into the rubber exhaust hose and the Vetus water muffler. The actual position of the injection port will probably be dependent on how much we can maneuver the hose and water lift. Steve would also like to see the pipe sized up to two inches in an effort to lower the back pressure on the system.

Steve recommended that I mock up the riser using standard PVC pipe, which I did on Sunday. The hard part was getting the piping stabilized well enough to have some confidence that I could repeat the performance.

Let’s fire her up!

Another shot.

After Marking joints and checking that the horizontal  and vertical sections were level and plumb, I feel like this is a pretty good model of what we need. What I don’t know is whether I can really get that close to the wall on the right hand side after adding insulation. I also have to provide hangers at the elbows to support the structure. This is especially true with the flexible bellows that will be used.

So, we are making progress and it feels good. Melissa and I are both itching to get Galapagos back out for more adventures. The fall weather in the Puget Sound has been spectacular and we are missing it!

Days like this are fading fast!

Days like this are fading fast!


12 thoughts on “I Heart Exhaust Elbows

  1. Okay– so I have two questions are the read=

    1) What happened to the engine when the Exhaust Elbow failed?

    2) What is the net gain + purpose of the ‘exhaust Bellow’? What does it bring to the table that was missing in your system? Would love to hear what you/Steve have to say so we can also understand his expertise…

    • Thomas,

      The first time the exhaust elbow failed, we were bringing the boat up from Astoria and were either in Bellingham Bay or headed that way. By the time I discovered the failure, the weld had failed completely at the same joint that you see in the first photo and water was streaming down the pipe while hot exhaust blew into the engine room. After stopping the engine, I called our diesel mechanic and asked for advice on how to proceed. He had me remove the broken elbow from the exhaust manifold and check to see if there was water standing in there. There was no water that I could see. I then started the engine for two or three seconds while holding a rag in front of the manifold to catch any water or debris. Fortunately, I only got a big old dose of exhaust gases, indicating that water had not run into the engine. Later, after we had the weld repaired and we were able to run the engine thoroughly, I continued to check the oil looking for signs of water. We never had any water in the oil which was a huge relief.

      The second time the elbow failed, we had been watching it carefully and had fitted a collar around it along with a muffler repair kit I had brought along for the the purpose. This bandage held well enough until we got the boat back to Tacoma. After docking in our slip, I checked the engine and could tell by moving the elbow that the weld had parted again. The collar had held everything together well enough and again, there was no damage to the engine.

      The exhaust bellows is also called an expansion joint of flexible hose. All of these things are like a pleated accordion that can flex and bend with the motion of the engine. The type we are talking about are made of stainless steel and are made of multiple plys of steel to provide redundancy and strength. If the riser is going to be as large as ours needs to be to rise above the waterline, having one or more of these flexible joints is necessary to allow the engine to move without imparting large stresses into the piping. Diesel engines can move a lot on their engine mounts so the exhaust needs to be able to absorb that motion without destroying itself.

  2. God bless the engineers! Sounds like you are on the right path. It took us a few tries to get the design of our exhaust elbow right as well. Let’s not talk about the frustration of the lack of a workable exhaust solution for each engine just being ready to go anywhere on the market, so we don’t all bang our heads in frustration. When Mark was redesigning ours I kept on saying “what the heck did previous owners do?!?!?!”. I knew the boat had been sailed and yes, the engine had been used so why on earth was it so hard to come up with a fix.
    FIngers crossed this is the fix!

    • Like guess if this is the worst problem we have we are doing pretty well. In our case the previous engine was getting water in the oil and the engine had to be replaced. This boat is do old there is no telling what the first exhaust system looked like. I think when you are refitting and old boat , prettying everything ends up being customized. Once we get it all done we will be carrying a lot of extra pieces before we go on the big trip.

    • We are talking about the exhaust elbow. After the exhaust elbow we go to flexible exhaust hose that runs to the vetus muffller and then aft towards a similar arrangement to yours. Your elbow is probably somewhat similar to the stock unit that came with our engine which we are concerned may allow raw water into the engine under certain conditions. The larger elbow we are designing has to have stainless flexible couplings. Rubber exhaust hose can’t be used before the raw water injection port.

      • Michael,

        Oh, I see. You are sort of redesigning the exhaust elbow itself.

        Regardless of the redesign, the fact you have a vetus muffler means you will block your water exit if the engine ever overheats (the muffler will melt on the inside – you can only know for sure it is melted by cutting it open). Ask me how I know this.

  3. Geez……
    I keep coming back to the real question, why? What is it about the new diesel (and/or it’s installation) that apparently is causing the unsettling possibility of seawater back up or siphoning? Or is somehow the vetus water lift? Or is it too long of a run? Or too high rise or too large dia hose or combo there of… for the new diesel to properly purge the sea water? Scary to keep throwing money at the problem. Just thought I’d mention that maybe there’s a ’cause’ of the problem that could be fixed easier and cheaper than all the fancy welding, engineering and so forth.
    Sorry for sounding ignorant. I know you’ve thought it through very well and thouroughly, but I’m just saying….
    BTW, sure is nice to see her “out there” Nice JOB!

    • Good to hear from you again John. Maybe we are just unlucky but I suspect this has been a risk for some time. We found the blog of the owners before you and they had a similar issue of water entering the engine back in 2006. They had just returned the boat to the water after a haulout and the next day they found water in the oil. Of course you found water in the oil of the Ford Lehman engine last year and suspected that it was from the freshwater side.

      I do think that the long run of exhaust hose after the Vetus muffler may provide a quantity of water that in certain conditions can work back towards the engine. Since there is a sizeable gooseneck before the exhaust hose exits the boat, there will always be a good bit of water standing in the line. Of course it isn’t a completely filled line but we probably need to measure the back pressure to make sure it is within range for the engine (about 42 inches of water). I intend to have a quarte inch port installed in the new elbow so that we can take a measurement.

  4. We join you with the non-working engine blues! And heavens did you see the waterspout off Anderson Island? Guess it was a good day to be at the dock. Hope your exhaust repairs go smoothly!

    • I checked out the waterspout photos. Impressive. We had a pretty good downpour here but by the time I got down to the boat, it was all sunshine and fresh breeze.

      I just caught up with your tranny woes on the blog http://svelsa.wordpress.com/. I bet getting that transmission out was not as much fun as the brochures would lead you to believe. While a fresh engine is a beautiful thing, I think you are probably right to get the transmission fixed and keep on trucking. Plus you will have two transmissions (and the knowledge of their maintenance) when you are done and that will be useful in the future.

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