How would you feel about this?

Bill_N

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Went to look at a boat yesterday. 34' Fitz custom being used for charter. Engine is a Cummins 6CTA 420HP Diamond with a ZF 280-1 with approx 1800 hrs. Pics I received prior to trip were much better than the boat in person. Needs a lot of TLC, small items fixed and some of the fixes I saw were kind of half assed which is not my style so I was lukewarm on it prior to the engine run.

Engine room is pretty clean and has good access. Everything looked pretty good there. At start up I noticed the oil pressure gage was pegged. Owner said it flucuates (there is one on the engine). Engine noise in the wheelhouse wasn't bad. Floor and hatches are well insulated. Owner took it out of the inlet in a 10-15 kt SW with 3-4’ swells rolling in. Ran right through at 18 kts. Went out 4-5 miles and I ran it in all directions for about 20 minutes - handles good. Coming back the owner spun it up to 2600 rpm redline and the turbo hose blew off the engine. Hose clamp broke. Came in on idle and anchored up. Tried to put the hose back on but couldn’t get it lined up and it seems short. Looked like an original item and needs to be replaced.

Should all hoses be replaced periodically? Anyone heard of a hose blowing off like that? Is this a sign of some underlying issue or just a coincidence?

I have pretty much decided to pass on the boat but this is kind of bugging me.
 

BillD

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Went to look at a boat yesterday. 34' Fitz custom being used for charter. Engine is a Cummins 6CTA 420HP Diamond with a ZF 280-1 with approx 1800 hrs. Pics I received prior to trip were much better than the boat in person. Needs a lot of TLC, small items fixed and some of the fixes I saw were kind of half assed which is not my style so I was lukewarm on it prior to the engine run.

Engine room is pretty clean and has good access. Everything looked pretty good there. At start up I noticed the oil pressure gage was pegged. Owner said it flucuates (there is one on the engine). Engine noise in the wheelhouse wasn't bad. Floor and hatches are well insulated. Owner took it out of the inlet in a 10-15 kt SW with 3-4’ swells rolling in. Ran right through at 18 kts. Went out 4-5 miles and I ran it in all directions for about 20 minutes - handles good. Coming back the owner spun it up to 2600 rpm redline and the turbo hose blew off the engine. Hose clamp broke. Came in on idle and anchored up. Tried to put the hose back on but couldn’t get it lined up and it seems short. Looked like an original item and needs to be replaced.

Should all hoses be replaced periodically? Anyone heard of a hose blowing off like that? Is this a sign of some underlying issue or just a coincidence?

I have pretty much decided to pass on the boat but this is kind of bugging me.

It's not totally unheard of (but rare) a clamp to breaking on the silicone hose between the turbo and the after cooler on a Cummins after cooled engine. Clamps get weak, rot or just break. It happened to me once.

When it does happen to usually get the "air horn" sound until you power down the engine and the turbo stops generating air pressure.

The hose blowing off the after cooler pipe or tubo pipe is not big deal. More concerning is the possible cause being an extremely "plugged" after cooler that is not letting the compressed air pass through it. Or could just be a busted clamp.

How old are the 6CTA 420s. When was the last time the after cooler was serviced ??

You stated the engine reached 2600 WOT....was that an "accurate 2600" via photo tach on the flywheel or reading off the analogue tach ??

Bill D
 

Bill_N

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1999 engine. No air horn sound. I was standing on the hatch and felt a little push when it went. Said he did the after cooler 2 years ago. 2600 rpm as indicated on the instrument panel tach. I should add that rpm's were still climbing when the hose let go.
 
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captainlarry84

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Good boat with good power. If you could not get the hose on the turbo it sounds like the hose may have had an issue once before and it was cut a little. You will be hard pressed to find a better 34 that the Fitz.
 

Bill_N

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The two flanges don't line up. Not sure if there's any adjustment in the tube but the alignment issue takes up some of the length. He wanted to get some new clamps and a longer hose. Not sure if that's something you can buy cut to length like that.

I liked the layout and the way the boat ran (until the hose let go). It would take some work to make it what I want though.
 

BillD

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The two flanges don't line up. Not sure if there's any adjustment in the tube but the alignment issue takes up some of the length. He wanted to get some new clamps and a longer hose. Not sure if that's something you can buy cut to length like that.

I liked the layout and the way the boat ran (until the hose let go). It would take some work to make it what I want though.

Bill,

On my 6BTA 370 Cummins there's a high quality stainless steel tube between the turbo out let and the after cooler. The tube is connected by two very short pieces of hose. One piece of hose on the turbo side and the other short piece on the after cooler side.

I have to loosen all "four clamps" and kind of "wiggle" the 2 hose pieces and the tube into place then tighten all up.

Plus if tube and hose get red hot @ cruise speeds.

Finally, I would NOT give up on the boat or engine/s over this incident if it is a busted clamp.

The 6CTA is a very good solid engine.
 

Bill_N

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Bill, Is that SS tube a stock item or something you added? What kind of heat does that hose/tube see anyway?
 

BillD

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Bill, Is that SS tube a stock item or something you added? What kind of heat does that hose/tube see anyway?

Factory OEM, comes painted. Paint will turn brown because of the heat.
I buffed the paint of the tube on my 6BTAs

I haven't touched the tube @ cruise speed...gets hot...don't plan to !! :D

cummins_6cta83 turbo tube.jpg
 

Bill_N

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Spoke to the owner today. He was able to buy a 1" longer hose at a Cummins dealer and double clamped it. Said it ran fine afterwards. I think there is a tube like that on the CTA and he probably could've loosened the front to get it more in line with the turbo flange as you pointed out.
 

BillD

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Spoke to the owner today. He was able to buy a 1" longer hose at a Cummins dealer and double clamped it. Said it ran fine afterwards. I think there is a tube like that on the CTA and he probably could've loosened the front to get it more in line with the turbo flange as you pointed out.

Very very good motor

If you are still considering the boat, take some time and read "Tony's Tips" and tech articles as applicable to the Cummins 6CTA and marine diesels in general.

Seaboard Marine - Custom Marine Diesel Repower Specialists

Good luck, keep us posted.

Bill D
 

Bill_N

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I have read some of his stuff and there is a ton of great info there. I've been an outboard guy for close to 30 years so diesel engines are not my comfort zone.

I'm thinking about making an offer on the boat. If I end up buying it I'll have a ton of questions along the way.
 

BillD

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I have read some of his stuff and there is a ton of great info there. I've been an outboard guy for close to 30 years so diesel engines are not my comfort zone.

I'm thinking about making an offer on the boat. If I end up buying it I'll have a ton of questions along the way.

If ya buy, we'll help ya set the motor up correctly, do the main service points and keep it running. A little bit of tweaking !!

Tomy on this site has a 6CTA 430 in his 36 Wayne Beal.

Also, spend the $25/yr to join boatdiesel forum. Hundreds of Cummins marine diesel owners on the site and Tony Athens is the Cummins moderator. Best $25 you'll even spend as a marine diesel owner.
 

Bill_N

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Sent the deposit check out this morning. Need to find a good Cummins guy in south NJ to check it out.
 

petrel

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Get it checked out. I had a similar experience w/ a 6BTA 315 hp w/ less than 2000 hours on a boat I bought. Turned out the engine had a bad piston and a lot of base pressure and blow-by.
 

Bill_N

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Survey was yesterday. Eckel's Marine Diesel sent a guy to check the engine. On visual inspection he thought there might be a head gasket leak and slight fuel leak. Took it for a spin and she cranked up to 2600 rpm again and didn't sound bad to me but after about a minute you could smell anti-freeze. Head gasket was leaking as he suspected.

He recommended doing the head gasket, injectors, turbo, aftercooler and heat exchanger service (which hadn't been done in a long time) as well as replacing all the old hoses and repairing the fuel pump. Ballpark estimate is about 6k. The seller did not want to cover this so I backed out.

I should've followed my gut on this one. Boat showed signs of neglect that turned me off at first and I should've known the engine was probably neglected as well. Lesson learned.
 

BillD

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Survey was yesterday. Eckel's Marine Diesel sent a guy to check the engine. On visual inspection he thought there might be a head gasket leak and slight fuel leak. Took it for a spin and she cranked up to 2600 rpm again and didn't sound bad to me but after about a minute you could smell anti-freeze. Head gasket was leaking as he suspected.

He recommended doing the head gasket, injectors, turbo, aftercooler and heat exchanger service (which hadn't been done in a long time) as well as replacing all the old hoses and repairing the fuel pump. Ballpark estimate is about 6k. The seller did not want to cover this so I backed out.

I should've followed my gut on this one. Boat showed signs of neglect that turned me off at first and I should've known the engine was probably neglected as well. Lesson learned.

That is too bad.
A good motor with a great long term track record.
Simply abused from hour #1
Happens way more than you'd believe and most times the owner/s don't even know !!!! :D
 

Bill_N

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That's what the mechanic said. He sees a lot of diesels with 4-5k hours that have never had a wrench on them. Change the oil and run them. Then the owner is shocked when it blows up.
 
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