New Diesel Engine owner (sorry, it's a yanmar)

[Gary Marshall]

I just wanted to greet everyone.

I just bought my first Diesel. An Albin 28 2005 model flush deck powered with a 315 yanmar. I wish I could have gotten a cummins B series, but that just isn’t available in the flush deck design I wanted.

That said, I will be reading and researching as much as possible to keep this engine working well for as long as possible. It is the original engine, and had about 900 hours on it. It was in fresh water most of its life, and then it moved to Florida for a couple of years where it was flushed with fresh water after use.

Now….it is working commercially as a fishing boat, 10 – 12 hours per day, 6 – 7 days per week, going between idle and 7 knots, 98% of the time.

There are any boat projects on the go, as I learn the vessel, but one of the first is to reduce the pitch of the prop as I am just getting about 3600 rpm at WOT. I did get 3700 rpms measured on the tach when I sea trialed the boat, and the engine survey done the year in front showed the true rpms seemed about 150 more than the boat tach. Either way, the boat needs to be propped for its current sea conditions and additional weight with coolers and ice, etc.. I think a 2″ pitch drop should do it.

Additionally, looking at changing from the Racor 900 series fuel filter to one of the recommended multi filtrations setup from SBMAR. I don’t have any issues now, but want to prevent them down the road as will probably do 2500+ hours per year.

Topic

[Gary Marshall]

Exhaust Modications

Hi all –

Long post warning… 🙂

Just wanted to document what modifications I have done so far with my exhaust. I am a novice, and learning, so critical comments are welcome.

I removed the exhaust elbows off the engine and inspected the turbo. It looked similar to my previous inspection in late 2017, with some rust present, but the flan blades and such still looked in good shape. Of more concern was the unevenness where the elbow bolts onto. I did my best with the orbital sander, wire brush and hand file to remove all exterior rust, apply an ospho rust treatment, and paint the exterior with a high temp 2000 F paint, and ensure the mating surface was level. I bolted back on the two elbows with new v-clamp and metal gaskets (it’s a real pain to ensure the gasket is in position before tightening down, with the limited access). I had removed some 2” insulation above the mixing elbow so I was able to rotate it slightly more, and raise it slightly. <br /><br />I replace the 4” exhaust hose with a new one, as the old one had a noticeable bulge in one area, and I have not replaced it since I owned the boat in 2017.

The Centek muffler I removed, and added a 1” Groco thru hull which I glassed in with a mix of csm/woven mat, using epoxy resin. A 1” hose attaches to this, and runs down to the bilge, with a Groco bronze valve on the end, which is easily accessible from a hatch in the cabin (behind the steps). Unfortunately this muffler is under the water line, so exhaust water always remains in it, and I wanted a way to remove all exhaust water from the system.

I would have liked to put in a surge tube between this Centek muffler and the engine elbow, but the room/height I don’t think would have allowed for an effective design, as the existing slope from the exhaust elbow I did not want to make any more gradual.

Now, as the Centek muffler is below the water line, I made a goose neck using Centek 5” fiberglass tubing from Defender.com. I cut the angles using a miter saw & angle grinder (as the miter saw blade was not large enough). I generally made 15 degree angle cuts, so the angle was more gradual heading up the goose neck, with a steeper downhill run before exiting the boat on the port side. I raised the gooseneck to just below the floor, which was the maximum I could easily do it, still trying to ideally keep it slightly lower than the exhaust on the engine, for a safety margin.

Now, the boat has launched, and all had worked well, except for the following flaws.

When the boat is light, the top of the gooseneck is above the water line comfortably. However, when the boat is fully loaded with ice and fuel, water sloshes over the gooseneck whenever the boat rolls. This is very dangerous as the valve needs to be open whenever the engine is off, and the bilge pumps/float switches need to be working well. Otherwise if the valve is off, the centek muffler is likely to fill and water rise in the exhaust system, to the level of the gooseneck/exhaust elbow, and the engine will drink some more saltwater.

As a temporary measure, we are opening the new muffler valve, and plugging the exhaust with a foam buoy shaped to fit the internal 5” fiberglass elbow to reduce water entry.

As a longer term measure, I plan to either raise the height of the goose neck by seeing if it can fit inside the “wall” of the boat side. I might take Tony’s suggestion in another post and utilize a square section for the exhaust here, to ensure I keep at least the same surface area as the 5” tubing, as I don’t think the 5” tubing itself will fit here). If I have space for this to work, the only issue would be that the height of the gooseneck will be above the height of the engine elbow, so I risk flooding the engine if the valve is closed, and there is excess sea water in the system (either from entering over the raised elbow, or from cranking the engine excessively if it has a starting issue)<br />Or, keep the existing goose neck, but rather than route the exhaust out the side of the boat, I have enough room in the transom at the port side to bring it up and out the boat, above the swim platform, well above the water line. I assume the exhaust might be a little louder here as it wouldn’t be exiting in the water, but for sure, water should not be able to enter the exhaust via the exit, and even if it did, the goose neck would add significant protection, and I would still likely open the valve to drain water in the system.<br /><br />Happy to hear any criticism, thoughts, suggestions….

 

[Gary Marshall]

Thanks, but not sure what you are referring to here. I had posted a lot of pics in the first few posts, I think on page 1.

[Woo]

Correct. The longer you can make it, generally the better off you are. Keep it parallel to the waterline.

From what I recall of your engine installation you have ample room to add a good section.

[Gary Marshall]

That doesn’t look too pretty!

I changed my yanmar cast iron mixer and riser elbow to cast 316 replacement versions back in late 2017, so I am thinking I should be good there.

My captain brought the boat back around from the port where it was in Bridgetown to Consett Bay where we fish from (other side of the island) this morning. The engine sounded fine, and no more issues with water in the oil so far, so all indications still point to water from the exhaust.

However, we did have an oil leak with oil pooling on the side of the valve cover. I believe it is coming from where the diesel lines enter the cover, there is like a rubber boot around the lines. The rubber boot is more visible on the inside of the valve covert though. Looks like a couple of them are leaking.

[Tony Athens]

Have you looked inside your “cast Iron” mixer? They do “rot thru” and when they do, guess what?

[Gary Marshall]

Thanks! I have been pouring through Tony’s articles (not for the first time) and some things which were not as clear to me initially I think I am understanding a bit better now.

So the surge tube basically is an inline pipe in the exhaust, which will normally drain of water, but if a wave or rock of the boat causes water for some reason to come back up the exhaust, it will fill that “dummy” end of the “Y” before it is able to go back up the exhaust hose to the engine. I like it. I will see what room I have, and what might work in my application. I think I might prefer a larger or longer dummy section. Maybe add a piece of dummy hose there which is capped, running under the actual exhaust hose. Might provide more security in heavy seas with engine off, or if on hauling up the operator lifts the stern of the boat before the bow.

[Woo]

Anti-reversion = anti surge tube.

I’ve attached a couple of pictures of my own to assist picturing it. The first picture is obviously the parts for a pair of engines. The second pic shows it installed.

Quite a bit written on this site about this.

1 user thanked author for this post.

Gary Marshall

[Gary Marshall]

Thanks for that reply.

I had not heard of the “Y-piece anti-reversion tube” before. I will have to do some research on it, looks like some sort of internal “flapper” one would put just after the mixer elbow, or perhaps further down the line.

Seems like some of the local commercial boats have put some sort of “water lock” in the system with a drain. Basically a fiberglass container, at some point in the exhaust, which has a drain that you can open when you turn off the engine. Any seawater in the system will drain into the bilge. You just need to remember to close the drain, or turn back the valve before you start the engine. I do want to ensure whatever i do is “fail-safe”. And regardless of the system, it won’t introduce much additional “back pressure” (that I know little about, other than reading on sbmar).

We got the engine started back yesterday evening, and the plan is to use it for about an hour today, and then change the oil again. It started easily so hopefully that is all a good sign.

[Woo]

Whilst I agree your exhaust leaves room for improvement, and by looking at your photos in post #27320, the addition of a Y-piece anti-reversion tube would be a wise and simple addition.

However, given the intermediate “hard start” prior to now, I think the aftercooler could be a candidate here.

1 user thanked author for this post.

Gary Marshall

[Gary Marshall]

Water in cylinders and sump

Hi all,
I’m trying to understand why this would have happened and how I can stop it from happening again.

The engine has on 8,700 hours, 8000 of which we have put on since we bought the boat in Jan 2017.
My boat was on a 4 day commercial fishing trip. My captain went to start the boat on Thursday morning to head home, and just heard “clunk”, as the starting motor would not turn the motor. We had assumed starting motor issues, as while it had never given trouble we were planning to get it serviced soon. I got the boat towed back to shore that day and offloaded the catch on Friday. The mechanic was a no-show on Saturday, and on Sunday I just decided to check the oil (which had just been changed before this trip) and realized it was about an inch and a half above the maximum mark on the dip stick. I then tried turning the engine using a socket on the flywheel and could not get it to budge. I got the oil pump, and pumped the oil up through the dipstick connection to check it, and at least a gallon of clear salt water came out first, before oil started to come.
Note that my coolant levels were fine, and my coolant is a bright orange colour. Definitely was not coolant in the oil.

Unfortunately my mechanic was a no-show again on Sunday. I removed the valve cover, but quickly realized that removing the injectors was beyond my limited knowledge. I arranged for a different mechanic to come on Monday (yesterday) and using a 6mm threaded rod devised as a slide hammer, he was able to remove the injectors, after removing the fuel return line. After squirting some penetrating lubricant down the injector holes, we were able to turn the engine by hand. Water hit the roof of the cabin from the pistons pushing the water out of the cylinders. We then cranked the engine briefly using the starting motor (with seacock closed) to clear out the remainder of the water. We then stopped for the evening due to fading light, after putting some more rust inhibitor lubricant in the injector holes.

I believe he will use diesel to flush the engine today, followed by an oil change or two. But any advice /suggestions here is appreciated.

Now, the main possibilities seem to be either relating to the oil cooler, or maybe an issue with the exhaust mixing elbow, or seawater back up the exhaust into the turbo, and then engine.

The engine has been working flawlessly without issue, and this trip was no different. My captain is also excellent in terms of picking up a change in engine noise. He would have run the engine for about 16 hours that day before switching off the night about 9 pm, and drifted till 4 am the morning when he went to start back up and have the issue. The sea did get rough overnight (but he has operated in plenty of rough conditions before also over the last ~ 5 years).

I would think that if it was the oil cooler, it would have had to occur while the engine was running, and he would have likely noticed some change in the engine noise. He would have idled for about 3 hours after dark, so may not have noticed any change to exhaust gases/smoke. I’m not sure what would be expected here, but I don’t think the engine would have liked a gallon of water in the sump, and cylinders full of water. I’m also not sure the cylinders could easily get full of water in this manner, via the engine running. So I am doubtful of this.

In relation to the exhaust. I changed the stock cast iron yanmar exhaust riser and mixing elbow with stainless steel replacements from HDI Marine back in 2017. (https://hdimarine.net/product/hot-1-stainless-steel-exhaust-riser/ ). I had taken pics of the exhaust at the time and Tony advised that sea water appeared to have gotten to it at some point in time. In installing the new riser/mixing elbow, I rotated them slightly more, to get about an inch more height (before butting with the floor of the boat). Again, I have not had any sort of issue with water in the oil since that time.

I will also mention that occasionally this year while the boat has been on the open ocean drifting, my captain has had a “hard start” where he has to crank the engine slightly longer than normal. Normally the engine starts very easily, and never gives trouble starting at the mooring. He put this down to the boat listing slightly on one side while drifting, and thinking it was fuel related. I’m not sure I agree with this, but it does not happen very often. Note that the boat is also very loaded up with ice, fuel and so on for these fishing trips, so sits a little lower in the water.

My expectation is that sea water coming back through the exhaust is the culprit, and even though I have never seen sea water in the sump before on doing an oil change, or noticed the oil level being high, perhaps it didn’t happen in this quantity, and was the reason for the occasional hard start in the ocean.

If this is the issue, what options do I have? I can’t get the exhaust any higher, and the rubber hose that fits onto this runs at a decline from the engine, to the port side of the boat, then into a large fiberglass pipe running down the port side to the stern, exiting at the water level on the port side at the stern. I have no flapper valves. We used to stick a buoy in the exhaust hole when drifting but it used to come out easily, and at any rate, water would be in the fiberglass exhaust pipe anyway, so it might help with a “wave” but not with water coming up the exhaust due to an extended roll of the boat in heavy seas. I saw some suggestion of using a valve in the exhaust, but even if I could install one suitably, it would seem that was an accident waiting to happen, as forget it shut once, and you would have a major issue.
Sorry for the long post, but wanted to give as clear a picture as possible.

I have lots of pictures in my earlier posts above. Thanks for any help or suggestions.

[Gary Marshall]

We loosened the 2 exhaust elbows yesterday, and were able to rotate them without too much difficulty so that they are right up against the insulation on the bottom of the floor. Here are the new pics.

Rob – was trying to locate a protractor to measure the angle….but no luck! I know it must be more than before.

Might have mentioned this before, but we also made a foam plug to shove into the exhaust from the outside when the engine is not running. This is a just in case type thing.

[Rob Schepis]

Gary Marshall wrote:

Ah, ok – now I understand. yes – the standard swells are 6 to 8 ft, and can go quite a bit higher when we are out.

The mooring is in a bay, but it’s really just the open ocean with a shallow reef around the bay. And how the boat rides, the exhaust exit will be facing the sea swells.

Now that’s what I was talking about.

[Gary Marshall]

Rob Schepis wrote:

My comment about the conditions makes reference to the fact that the boat used for open water fishing charters, it’s not a wine & cheese picnic boat, so no doubt she’s out there rocking and rolling. How about your mooring, is that a bit bouncy or is it far inland fully protected?

Ah, ok – now I understand. yes – the standard swells are 6 to 8 ft, and can go quite a bit higher when we are out.

The mooring is in a bay, but it’s really just the open ocean with a shallow reef around the bay. And how the boat rides, the exhaust exit will be facing the sea swells.

[Gary Marshall]

Tony Athens wrote:

Just an FYI ……Your turbo is not that bad and it looks like it’s only happening when at the dock or when you shut down,.. Regardless, you need to address the issue. You should see nothing there but black smooth velvety carbon..

Tony

Thanks Tony! Glad it’s not the worst you’ve seen. I’ve fashioned a foam cork to shove in the exhaust when we are drifting in the ocean, but perhaps I should use it at the mooring as well.

I will raise it the 3 inches and hope that helps too.

[Rob Schepis]

My comment about the conditions makes reference to the fact that the boat used for open water fishing charters, it’s not a wine & cheese picnic boat, so no doubt she’s out there rocking and rolling. How about your mooring, is that a bit bouncy or is it far inland fully protected?

[Tony Athens]

Just an FYI ……Your turbo is not that bad and it looks like it’s only happening when at the dock or when you shut down,.. Regardless, you need to address the issue. You should see nothing there but black smooth velvety carbon..

Tony

[Gary Marshall]

Rob Schepis wrote:

There are 2 issues – spillover height over the LWL and the “flatness” of your exhaust coming off of the mixing elbow.

The Albin 28TE engine box boats have a spillover that is problematic on the Cummins but seem to just squeak by on the Yanmars. With the flushdeck boat the engine is a tad lower so your spillover is likely an issue but I’ve never measured it. Of course, cutting the deck and putting a tall dry riser is always the theoretical but seldom practical solution. You seem to have a a few inches where you could rotate the 2 elbows and gain “some” height.

By rotating the elbows and using that extra height you have there you will be able to get “some” more downward pitch coming off of the mixer. I put only a 5 degree list on that photo and now it’s an uphill run.. I know where you are and how you use the boat – if she’s only listing 5 degrees those are ideal conditions!

Thanks Rob – really appreciate the guidance from yourself and Tony (and of course anyone else that may chime in). Thanks for the pics you added to make everything clear. That was what I was thinking as well. I just wasn’t sure if the orientation of the water hose entering the mixer made a difference.

I will get 2′ of 1.5″ exhaust hose and re-orient how it enters the mixing elbow….this way I can gain about 3″ of height on the exhaust, and increase the angle.

Not sure what you meant by “if she’s only listing 5 degrees those are ideal conditions”

[Rob Schepis]

There are 2 issues – spillover height over the LWL and the “flatness” of your exhaust coming off of the mixing elbow.

The Albin 28TE engine box boats have a spillover that is problematic on the Cummins but seem to just squeak by on the Yanmars. With the flushdeck boat the engine is a tad lower so your spillover is likely an issue but I’ve never measured it. Of course, cutting the deck and putting a tall dry riser is always the theoretical but seldom practical solution. You seem to have a a few inches where you could rotate the 2 elbows and gain “some” height.

By rotating the elbows and using that extra height you have there you will be able to get “some” more downward pitch coming off of the mixer. I put only a 5 degree list on that photo and now it’s an uphill run.. I know where you are and how you use the boat – if she’s only listing 5 degrees those are ideal conditions!

[Gary Marshall]

Just reposting a pic for easy reference.

[Gary Marshall]

Tony Athens wrote:

You do realize that your “ALBIN” boat builder exhaust design is letting seawater back in to the turbo, correct?…………………………………………Not much else to say other than it needs to be de-designed……Until that is done, everything else means zero in my book.. Ask Cummins or Yanmar–They’ll tell you the same ….There is no if’s or maybe’s here.. It’s IPPSO FACTO………………………………………………………………….. RAW WATER and turbo’s do not mix..

Tony

Thanks Tony! I really appreciate your input. This is the first turbo I am seeing in person, so I really wasn’t sure. Initially I thought it was fine, but with the light the camera picked up on some flecks of rust showing it wasn’t 100%. I suppose it didn’t seem anywhere near as bad as some of the pics in the exhaust articles on the site.

I think the second set of pictures (which are clearer) may look a bit worse than it actually is, as I took them as I removed the dry elbow (which was showering rust everywhere) so some would have fallen just inside when it was removed. I didn’t think to sweep it out before taking those initial pics. But I do agree there is a problem!

Now, I guess the important thing to do is for me to understand how seawater gets back to the turbo. And then fix the issue. I am curious if this would be happening when the boat is at anchor or drifting, where waves are washing against the exhaust outlet on the side, and managing to travel up the exhaust back to the turbo…..in which case, perhaps using a plug on the exhaust when the engine is off might help (but not solve) the issue.

If it is something that would be occurring more when the engine is running, from the seawater exiting from the mixing elbow, coming back into the dry elbow and into the turbo…..then….this seems like a difficult one to resolve (without tearing up the floor in the boat).

I’m not sure if it is something as simple as seeing if I can take off where the water hose connects to the mixing elbow, and rotate the elbow so they gain a few inches in height, and change the angle at which the water hose is connected to accommodate this. (not sure if the water hose has to be entering the mixing elbow in a downward projectory or not)

Or, if a different exhaust can be designed that will be effective, that can use up the couple additional inches of height, utilized by the hose, without raising the floor….

Or, if raising the floor is the only solution…..

I am learning a lot – really looking forward to any possible solutions! Thanks! 🙂

[Author]

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