Turbo life for Cummins 6CTA

J

Joel_MD

Member
Jun 20, 2016
210
Chesapeake Bay
Boat Info
390 Motor Yacht, 2005
Engines
Cummins 480 CE
I have a 2005 390 Motor Yacht with twin Cummins 480 CE. Engines are a little north of 900 hours. This boat is used for bareboat charters so reliability is important, and I'm the kind of guy who likes to replace things at a leisurely pace before they break as opposed to having them fail at Murphy's whim. I'm thinking about pulling both turbos after winterizing next fall and having a turbo shop rebuild them. It will cost about $400-500 each for the rebuild. My question is, how many hours do these Holset HX55s typically accumulate before failure? I realize turbo longevity depends a lot on usage. When I use the boat it's probably about 50-50 cocktail speed/planing speed. I have no idea how the charterers use it, but I'll assume worst case with a lot of time at higher RPMs. If a lot of you tell me the turbos will easily last 2,000 hours with this kind of usage, I'll probably go two or three more seasons before rebuilding them.
 
Tony Athens at Sea Board Marine has many examples in the 20,000 hour range without a rebuild, I'd say save your money.

The bigger concern around the turbo is water reversion. You could inspect the exhaust output side to ensure you have no rust/corrosion. I believe this exhaust design is OK in that regard, but due to the fact the elbow is a wet elbow it is prone to rust through if used in salt water. If this occurs you may hydro-lock the engine! I'd suggest inspections, though its probably worth replacing now.

The biggest factor for longevity on the 480CE is proper propping. From the factory, the boat was propped right on the 450c fuel curve. If you're running heavy, you may be over propped.
 
I'm very familiar with SBMar and BoatDiesel. When Tony writes about C-Series engines lasting that long I was just thinking block and heads, not that the turbo would actually last that many hours.
 
I have a sea Ray 400 sedan bridge 2001, I bought it 2 years ago with 1,100 hours on the engines and the Previous owner changed the turbos 6 months before sale the boat, so I imagine he change the turbos at 1,000 he show me the invoices, this is a cummins 6cta 450 HP diamond, the engines are running great.
I imagine it depends how you use the boat or maintenance.



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FeLizDream said:
I have a sea Ray 400 sedan bridge 2001, I bought it 2 years ago with 1,100 hours on the engines and the Previous owner changed the turbos 6 months before sale the boat, so I imagine he change the turbos at 1,000 he show me the invoices, this is a cummins 6cta 450 HP diamond, the engines are running great.
I imagine it depends how you use the boat or maintenance.
Click to expand...
It would be nice to know why the turbos were changed. I don't suppose you're still in touch with the previous owner?
 
Are you looking into rebuilding to solve a problem, or just to be proactive? I'm sure you have read that salt water is a big reason for turbo failure, but if you don't have an issue then go boating. What I would suggest is inspecting the exhaust risers for pitting and leaking. Once you have that apart, you can inspect the turbos for bearing play along with rust and scale
 
I just had my starboard turbo rebuilt by a shop in West Palm, FL. All the damage was rust on the inside and mating face of the turbine housing. He milled out all the rust to all good metal then inserted a sleeve to match the opening spec. You can see the sleeve edge all around the mating face. He also replaced the entire rotating assembly and did all the appropriate balancing. Cost was about 1/2 of a brand new turbo, and about 2/3 of a "new" rebuilt. Total hours was 1400 and 16 years. He told me mine was pretty typical for a 16 year old boat in salt it's whole life. Here are before and after. I plan to have the port done as well.
5627cd3d41ce7e838a3c3eb0a962393b.jpg
7ace43d69d2353f8f1b0df3cfb208c3f.jpg



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