Turbo jamming

[Nigel Kittow]

Hi all. First post and looking fir some help. I live in Vanuatu where specialist marine services and advice are thin on the ground.
I have twin 1996 6BT 210 in Caribbean 32 with 5000 hours running Holse H1C turbos.. Around 18 months ago Stb engine started pouring out black smoke and had hole in the core assembly. To cut a long story short replaced the exhaust housing and core with new genuine Holset parts and was fine for 9 months. After not running for a month found the engine to be pouring black smoke under load. Removed the air filter and found the shaft jammed. Freed it up and it ran good as gold for 3 months then after 3 weeks of no use found it to be sticking again. If I press the turbine towards the bow I can jam it against the housing but if I press it towards the stern I cannot. This suggests to me it may not be centered properly.
Appreciate all help and advice to sort this. Many thanks, Nigel

Topic

[Nigel Kittow]

Photos

Decided to wait before pulling the turbo as the spare elbow was not in good shape and the turbo is currently spinning freely. I need to use the boat this week too.
There is little fall in the elbow So easy to imagine how some water could get back into turbo.
The distance from the top of the flange to the boat floor is 210mm so allowing clearance I guess we have about 150mm of available rise.
I have attached a drawing for your comments. It would allow an easy connection To the current exhaust with little to no modification.
The port exhaust mixer elbow is unpainted stainless which suggests it may have been replaced at some time. It too has minimal fall.
Internet is a bit dodgy so hope it all loads ok
Thanks

[Tony Athens]

Do # 1 & #2 FIRST and get Rob & I good pics ASAP.

.I’m online all weekend

[email protected]

………..The rest will come as needed.

Tony

[Rob Schepis]

Your “numbers 1 – 6” will get you by for that needed run but won’t do anything to prevent a “gulp” due to inadequate spillover height. And, no, the factory supplied wet elbow does not get used in a proper custom dry riser exhaust build.

[Nigel Kittow]

A plan???

I have a real need to use the boat next week and just want to run past you guys what I plan to do on Saturday and get your opinion.
1. Plenty of photos of the setup. Will get some of the port engine as well .
2. Remove the elbow and inspect for water ingress into the turbo exhaust housing. Photos
3. Replace the elbow with a pressure tested spare(which hopefully I have access to. )
4. Ensure the turbine is spinning freely.
5. In a week or two pull out the whole turbo, inspect the exhaust housing. Design and build a riser that prevents the problem happening again. Rebuild the core.
6.Check the port engine as well

Thoughts?
Is it possible to repair the elbow/mixer and still use it in the exhaust design?

Many thanks for sharing your expertise
Cheers, Nigel

[Rob Schepis]

Nigel Kittow wrote:

…
I am just sure how I am going to fix it here in Vanuatu. Limited resources at best.
Cheers, Nigel

All you need is a working brain, a camera and an accurate tape measure. The design and build is done in a shop somewhere else and if everyone does their job, it all shows up on the doorstep for a basically plug and play install.

[Nigel Kittow]

I have read your tip sheets and it seems that it will be the problem. I have what i believe is a stock cummins elbow/mixer bolted directly to the turbo =. It does run down hill but is pretty easy to imagine with a leak in the jacket how water could leak back into the turbo housing. Will get photos this weekend and post back.
I am just sure how I am going to fix it here in Vanuatu. Limited resources at best.
Cheers, Nigel

[Tony Athens]

Nck,

“so I have assumed that exhaust design would have been sorted”

Ever heard of Mainship, Albin, Monk Trawlers , and quite a few Armsrong and Moose boats that I have to redesign exhaust systems on due to issues EXACTY like you are describing.. ?? These builders never knew what “gravity” was.

These are just five builders that I have personal interaction with, and that the buyer also “assummed”

Let get those pics ASAP..

Tony

[Rob Schepis]

Nigel Kittow wrote:

….. When we strip it down I will get plenty of photos…

Photos BEFORE you strip it down are very important as well. We want to see everything AS INSTALLED.

[Tony Athens]

To me, everything that has been posted points to one thing–An exhaust system that in letting water up to the turbo exhaust outlet..

You are only fixing the result of the issue, and not fixing the WHY part of the problem.. Have you really read the exhaust articles on this web site? I’d say no..

Let’s gets pictures of the engines as installed in the boat, plus I want to SEE INSIDE the exhaust side of your turbos..

Tony

[Nigel Kittow]

More info

Thanks Tony. I have posted more details to Rob. The Caribbean 32 is a common production boat that is still built today to the same design so I have assumed that exhaust design would have been sorted. I am following up though and trying to find out if there are have been previous exhaust design issues.
Photos to follow
Cheers

[Nigel Kittow]

More details

Thanks Rob. I will give you some more info and get some photos when we strip it next.
Caribbean 32 are a flybridge sportfisher built in Australia. They are the same design as a Bertram 31 and were being built under the Bertram label under licence. When Bertram went out of smaller boats, International Marine continued to build them but under the Caribbean label. So it is common production boat. I am making enquiries at the moment to try and establish if they have any exhaust design issues. The twin Cummins 210 is their standard engine configuration.
I have owned the boat for coming up 5years and about 1200 hours. First 18 months were in New Zealand then 3 1/2 years in Vanuatu. In Vanuatu she is used as a private game fishing boat with most trips being 10 mins around 1000rpm til warm, 30 mins at 2000 rpm, 6 hours at 1250RPM, a run home and 5 minute idle to cool. She lives in a flat calm marina.We do around 250-300 hours per year.
I am trying to find if the previous owner had any issues.
History
April 2016 the stb engine was progressivly producing more black smoke. It then suddenly poured out black smoke. Pulled the turbo and had a hole burnt through the heat shield, This turbo could have been 5000hours old though. Replaced with a cheap core assembly off email. Still smoked. The exhaust turbine housing was showing some corrosion and the space between the turbine and housing was bigger than thought ideal. Replaced the turbine housing. Ran fine for a round 6 months 75 hours. The first time runfter it had not been used for a month had black smoke pouring out under load. The turbine was jammed. Mechanic felt to much side to side play in the shaft.
Put the problem down to cheap part off ebay and replaced the core assembly with expensive genuine Holset part. As the mechanic was fitting it and tightening the clamp I do recall it jamming and he had to wriggle and re seat it to a position where it ran free.
Ran fine for 6 months again and then after not being used for a month was jammed again. Freed the turbine by hand and it ran fine for 2 months until not being used again for 3 weeks and again it was jammed. Freed it up by hand again and runs fine, no smoke and pulls revs.
We did check the oil feed when we replaced the core which seemed fine but did not prime the bearings.
I am awaiting arrival of a rebuild kit and new oil feed line. When we strip it down I will get plenty of photos and get back in touch.
Appreciate your advice

[Tony Athens]

Turbo Sticking

I suspect suspect salt water is getting to the turbo–“bad exhaust design”……………So to our poster..

Follow Rob’s advice–Very good pictures needed, especially showing the exhaust /turbo….

Tony

[Rob Schepis]

I guess I fell asleep in Geography class one or more times…had to Google your location, yes you are “out there”. Must be beautiful..

Yes, new turbos do need to be oil primed for first startup. But why the initial “hole in the core” ?

How about giving us history of your ownership of the boat, how it is used, numbers of hours between failures, etc. Is this a dive boat or drift fisher that sits and rocks and rolls all day in the ocean or is this a tour boat or trolling fisher where she gets fired at the dock and doesn’t shut down til she’s back to port?

AND photos! We cannot see anything or comment on what is going on without seeing it all. Photos MUST include engine room, turbo / exhaust pics, engine room vents, dorade boxes, exterior pics, exterior engine room (hullside) vents, etc etc.

The turbo pics should include the air side (compressor) with the air filter off and the exhaust side (turbine) with the exhaust installed and also removed for interior view.

[Nigel Kittow]

Lack of oil prime!

Just another thought.
I don’t think the bearings were pre primed with oil and the engine cranked without starting at installation. Is it possible the bearings were flogged on first startup resulting in increased play and so contacting the housing now?

[Author]

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