Albin 28 / Cummins Engine - poor exhaust design

[Robb]

I've been wracking my brain on how to fit a better exhaust design into my Albin 28 with a 370 Cummins (but this applies to all Cummins engines in the 28's). At rest my exhaust side outlet is about 1/3 covered with water. My muffler is a 6"ID Vernatone straight through that is about 24" long.

As some of you who also use BoatDiesel.com know I have posted over there this problem back in the spring when I put a new ReCon engine in the boat. At the time I was worried about water intrusion into the turbo and engine AND Tony Athen's told me that with the factory Albin exhaust design I would be getting water in the engine. The previous engine suffered an early death from water intrusion at 2800 hours. Now I rationalized it in the spring as "Albin made a 1000 of these boats and they are all working fine" so there cannot be an issue. I was in denial, I pulled the turbo at 50 hours and there is water getting to it. I have too much $$$ into this new engine not to fix the problem once and for all.

So I was in business this week in LA and went to visit Tony Athens of Seaboard Marine (and moderator at BoatDiesel.com) about this issue. After discussing a few hours I need to take some measurements and explore some options. We outlined 3 possible options to fit in our tight Albin space:

1. Change the turbo to a top mount. This is the cleanest installation and will give adequate spillover height (should be 12" minimum above static waterline). But- and a big but- is that I would have to raise the engine box I believe. Taking measurements tomorrow.

2. Develop a dry riser that meets these requirements like coastalrunner did this this past winter. This is a great idea that shows promise. Here is a link to his post. viewtopic.php?f=5&t=7941 This combined with a water lift muffler would make the system very safe- if it can fit. See this Seaboard Marine article on exhaust system design. http://www.sbmar.com/articles/designing ... st_system/

3. Develop something new like a exhaust shower that mounts above the turbo or any other good idea someone can come up with.

The purpose of this post is to 1. see if someone has already developed a solution that I can just implement 2. Start a brainstorming discussion to develop a solution that all Albins with of this build can use.

I want to take the boat out crabbing tomorrow, but now I am worried every time the boat rolls on beam ends I am slopping salt water into the turbo or worse...

Anyone solved this issue?

[RobS]

Have you measured/identified the static water line in the engine room so you know what you are dealing with? Very easy to do with some clear hose off a sea cock and hold it next to the turbo/elbow and note the water level. A photo would be great...

[jleonard]

How about using a water lift muffler?
When you do decide on a design you can make a mockup/pattern using Home Depot stovepipe, screw it together and send to a fabricator such as Marine Manifold on Long Island NY

I also want to say that when I repowered my Mainship with a Cummins I only had 9 inches above the WL and the outlet half submerged and I had no issues with water intrusion after 5 years ( I inpspected a couple of times). I had no muffler just a straight downhill run.
Hope this helps.

[Robb]

My red line on the photo is not a guess, it is from removing the turbo and looking at the standing water. My guess is that I´m +/- 0.25".

Note that the exhaust hose runs DOWNHILL from the straight muffler run to the stock Cummins riser. I cannot change this with the current components due to the center mounted inlet of the muffler causing the height offset in the mail run and the low position of the Cummins riser on the engine.

It is a known at this point that water is getting to the turbo. Our main use of the boat is fishing offshore and drift fishing cannot be helping the situation. JLeonard, I think a big part of my problem is the down slope mentioned above creates a pool of water that can easily slop water up to the engine versus a clean 9" drop run where the water is more back at the transom like your Manship. Thoughts?

I am trying to design in a lift system like in Tony Athens attached sketch, image 6. I will be taking measurements at the boat this afternoon.

Is this what other Albin 28 exhaust systems look like? Or is my earlier 1996 version "special"?

[Robb]

Also, Coastalrunner, if you are out there what OD 316L pipe did you make your riser from? 3" or 4" pipe?

[thomaslong]

I may be having the same problem. It looks like my turbo may need replacing after only about 350 hours of use. I posted on boatdiesel.com and received a reply that it is likely due to water intrusion through the exhaust. Before I pull the thing off and spend the money on a new turbo, I hope to learn something from this forum.

[jleonard]

I had a nice long downhill run in my Mainship and an exhaust flapper but I'm not sure the flapper really did much. I also had a custom dry riser that went as high as I could get it under the floor and a shower head that always drained out. Ala Tony Athens style ( he mentored me from afar).
You have a challenging situation to deal with. Wish I were closer as I'd love to help design a solution but one needs to be right there to solve this one.
I would still start by using stove pipe using all the deck height you have then go from there. Sometimes once you make the first mock up you have one of those "Aha" moments when the lightbulb starts flashing.
Crazy thought.... is there any space under the funnel for a riser??

[Robb]

I have worked with Tony over the last week on coming up with some options. I have 3 possible options that we have come up with and I want to present them here and get anyone's input. There is no clean solution and they all have some trade-off's. I want to thank jleonard for the hint to look into the odd spaces- that is how the under the cockpit strair idea below came into being. I will post each idea as a separate post with photos to keep them for getting too confusing.

After presenting all this to Tony, here was his reply:

"You have to make that call as what works for you..Albin just totally screwed up on the engineering and Cummins bought into it.. Just remember, the only thing that will protect the engine is HEIGHT, and that if you modify the hatch (engine box cover), you need 2" clearance above the dry riser for clearance to the insulation."

[Robb]

Idea 1- Top mount turbo

This concept would have me move the turbo from the current position to the port on top of the exhaust manifold. I would require some changes to the intake tubes, oil lines, etc, but these are pretty easy and standard. Basically the turbo gets mounted on top and a 4" dry section is fabricated from 316L SS and covered in insulation. This routes forward to a wet mixer where water in injected and attaches to the existing 6" hose and muffler.

Advantages
17" above waterline clearance
All water drains from the riser when not in use

Disadvantage
engine box cover needs to be raised ~6" higher. This would take fiberglass work.

[Robb]

Idea 2- Loop-d-loop

This concept would have me having an exhaust loop like coastalrunner previously posted. I would require minimal changes to the existing engine installation and exhaust system. It is basically a "bolt-on" fix. The only issues are very tight clearances and having to modify the engine box cover to get it to fix. It also has the lowest of all the spill over heights of the 3 ideas, although it is at the 12" minimum required and much better than my existing 5.5".

I have now pulled the saltwater washdown hose from the seacock and installed a clear PVC tube to use as a water level. All my waterline measurements for spill over and static water in exhaust system are now exact.

Advantages
12-14" above waterline clearance
All water drains from the riser when not in use
Minimal modifications to boat
Proven system by coastalrunner with acceptable EGT's

Disadvantage
Engine box cover needs modified for system clearance. This would take fiberglass work. I think it will fit with only the corner mods shown, but if not, the entire engine box will need to be raised also like in Idea 1.
System clearances are still very tight, i.e. hot exhaust close to insulation

[Robb]

Idea 3- Riser under port cockpit step

This concept would have a 4" dry section fabricated that mounts to the standard turbo location, dips down slightly and runs perpendicular to the engine to the port. It then rises up into the cavity that is located under the port cockpit step. I have access to this location from removing the interior panel at the aft end of the berth in addition to the engine room access. The dry section then does a 90 degree vertical turn up into this cavity and a 112 degree turn at the top to mount the wet mixer. All this 4" dry section is fabricated from 316L SS and covered in insulation. As the run is rather long it would need to be properly supported as part of the installation. After the wet mixer a 6" hose attaches to the existing muffler which we will have to glass on a 45 to line up with the mixer..

Advantages
~15" above waterline clearance
All water drains from the riser when not in use
No modification for engine box required, minimal modifications to the boat required.
Stock turbo location is used

Disadvantage
Saltwater washdown faucet, freshwater fill and vent need to be relocated.
Tight installation space

[Robb]

My current thoughts.

Currently, I'm very torn between the Ideas 1 and 3. I like the increased height of the top mount turbo to get maximum spill-over height but I do not like having to raise the entire engine box cover this amount. I get the feeling that Tony thinks Idea 1 is the way to go with the Top Mount Turbo. But as he said, I need to decide. Idea 3 has very few boat modifications, comparatively, but is more difficult to fabricate and install. The fabrication is more expensive also. I think there is somewhat more risk to the option also because I would be the first to do as the top mount is done on a regular basis on many boats.

I value any comments or ideas that you may have.

[catalina_mike]

Idea #3 put the exhaust in a space without insulation and adaquite clearance for heat dissipation IMHO. My mechanic was concerned with the water line and turbo on my vessel and the Yanmar. He pulled the elbow to take a look at the turbo. Not sure what I would do but you can tell the current setup traps water because of the layout. It looked like the muffler could go a in cho or so higher. Then that would decrease the trap size between the turbo and low spot. Looked like it would be more gradual to the muffler if you could raise it a inch or so. Great pictures and markups.

[jleonard]

I'm glad you came up with so many options! That's awesome. And I like your pvc mockups!

I can't think of much to help you decide. I am really at a loss for how to deal with changing the engine box. I have never had a boat set up like that, and maybe I have been on one only once or twice.
Would the box itself be more convenient if it were 6 inches higher? Would it be a better working height for fishing? Or sitting drinking a beer? Or would that make t less usable?
Could you raise it up using teak, or ipe, or starboard at the base and not fiberglass?

Do all those items under the step really have to be relocated? With the insulation around the tubes the area should stay pretty cool. You could add vent louver or a fan in there if that would make you feel better about the heat ppossibility. You would want to support the exhaust tube to the engine ideally. That way it would move with the engine. If you support to the boat the engine movement, might make it fatigue fail down the line. Maybe a soft engine mount if you attach to the boat would alleviate that possibility. Or a rubber muffler hangar, etc.

[Robb]

While I never did get a reply from Coastalrunner (it appears he sold his boat this summer), someone pointed me to his for sale ad on thehulltruth.com.

http://www.thehulltruth.com/boats-sale- ... old-2.html

It appears from the photos below that he was able to get the insulation on the loop-d-loop exhaust and not have to raise the engine cover. This will merit some exact measuring to see if I can do the same. Thanks!