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Discussion Starter #1
In the past small naturally aspirated diesels were the auxiliaries in cruising sailboats. Even on passage with a modicum of knowledge you could keep one going. Perhaps not all cyclinders but enough to propel the boat. You could have extra belts, filters and an injector feeling fairly confident.
Now virtually all recent boats have small turbo diesels. You would have difficulty even spec'ing a new boat with a naturally aspirated engine.

So the question to you wrenches is:

If the turbo goes, won't even spin, will the engine function at all? If so at what perecentage of its original shaft HP?. Are you better off physically removing it from the system? Given how expensive they are is it worth it to carry a spare(we carry a spare alternator)? If the engine can run without a turbo what does that do to the engine?


Thanks.
 

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Bristol 45.5 - AiniA
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I had an interesting experience with my son who is a BMW tech and who works with their very complex diesels. He looked at my old Westerbeke, which I can fix a lot of things and just laughed. He said that diesel turbo units are about the most complex items he encounters. You need a lot of training and access to special tools. I imagine a Yanmar one would be simpler, but still far from simple. Perhaps best to talk to Yanmar and see if they have a DIY manual for changing a turbo. If not, it would be a non-starter (if you pardon the pun).
 

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Discussion Starter #3
K does that mean it won't run at all if the turbo shat the bed?

BTW I have a turbo'd ecodiesel in my jeep summit. It's wonderful but I asked the local wrench what to do if it won't start when we are out fly fishing on the beach. His reply was "pray you can get a 4x4 tow truck before the tide comes in and alway park well above the high tide line".
 

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Hey,

If the turbocharger locks up so that the shaft won't turn, no, the engine won't run. The turbocharger is driven by exhaust gas, if the exhaust can't get past the turbine vanes then the exhaust can't get out. If the exhaust can't get out, the engine can't run (no gas out = no air in).

There are situations where the turbocharger won't work (generate pressure) but the engine will still run - burned turbine or compressor, etc, the engine will still run but will make much less power.

Personally I have no experience with turbocharged marine diesels so I can't offer any advice on spare parts.

Barry

If the turbo goes, won't even spin, will the engine function at all? If so at what perecentage of its original shaft HP?. Are you better off physically removing it from the system? Given how expensive they are is it worth it to carry a spare(we carry a spare alternator)? If the engine can run without a turbo what does that do to the engine?

Thanks.
 

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Beyond The Pale
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In my opinion, modern, auto-based, high-rpm Turbodiesels don't belong in smaller Sailboats. Who needs that much added power? Anyway, they aren't common. Bog-Standard non-Turbo Marine Diesels are still the most common kind, by far.
As to whether a Diesel will run with a frozen Turbo- it depends.
A friend of mine bought a Mercedes 300TD with a frozen Turbo. It still ran, but slowly, and smokily. He replaced the Turbo, and the Car ran again as well as it ever would. After a couple of years, I bought it from him, and put another 100K miles on it. Oil, a couple of lamps, wiper blades, and tires were all that I replaced. And then a tree fell on it...
My current 300TD has over 350K original miles on the clock...
The 30 year old Volvo Diesel on my boat is also original, but it isn't Turbocharged. It runs like a top- tickle the manual fuel pump lever a few times, and it starts right up.

(Those old MB Diesels were _heavy_; the 300TD 125HP Turbo series engines weighs something like 1,100 pounds. I've lifted a couple, with much mechanical assistance.)

"If the engine can run without a turbo what does that do to the engine?"
Again, it Depends.
Mechanical Fuel Injection pumps were calibrated for Turbo use, and would dump too much fuel into the cylinders at higher engine RPMs if the Turbo froze, leading to Smoke in the exhaust, and engine Coking. This could also cause Glow Plugs to burn out.
Older Diesel fuels were only fair lubricants, (Sulfur...), but raw Diesel getting past the rings could lead to cylinder scoring on starting when cold.
If you are talking about modern EFI Diesels, with modern low-Sulfur Diesel fuel, you have to be a bit more specific. I have no idea what each manufacturer has in the way of Exhaust Sensors and Sensing. It's all very Proprietary these days.

Someone else commented:
"If the turbocharger locks up so that the shaft won't turn, no, the engine won't run."
Simply. Not. True. Turbochargers are not displacement pumps, like piston pumps or Roots Blowers. At low or no RPM, enough exhaust gas gets past the vanes to allow the engine to start and run. Turbocharging depend on high Turbo RPM to work at all. A frozen or weary Turbo just adds back-pressure to the exhaust system, and messes with Injection settings.
(BTW- the Failure Mode is the Turbo bearings. Lack of oil or very dirty oil is Death to them. The bearings either get frictiony, they freeze up after being run hard and shut down too quickly, or they fail spectacularly, causing vanes to hit what's around them that they shouldn't hit. I've rebuilt more than a few, but with this distinction- they were made by Varian, and they weren't used in boats, that I know of.)

"Now virtually all recent boats have small turbo diesels... You would have difficulty even spec'ing a new boat with a naturally aspirated engine."
Volvo, Yanmar and most other manufacturers still offer naturally aspirated Diesels, from one to four cylinders, I just checked, and Catalina, Hunter and Beneteau offer them; I just checked again. Where did you come up with that claim? (You may have something if you are talking about custom >$500K Mega yachts, but since you didn't make that claim, I am assuming that you aren't.)

¬Erindipty
 

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Master Mariner
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If a turbo packs up you will have a decrease in air into the cylinders, a richer mixture because there won't be forced (turbo) driven air getting in. But the engine will still take air in naturally. A blown turbo will not hinder the exhaust as it is a turbine. The engine will still run, at reduced power of course, and smoke like a hippie. The smoke was the first indication you'd blown a turbo on the big sportfish boats. A dead giveaway. It happened fairly regularly. We carried spares, and with as much a a million bucks on the line in a tournament, our budget was somewhat greater than most sailors.
If you wanted to remove your turbo permanently, you would require different injectors at the very least. Possibly new pistons, rods and rings as well, and then you'd have to mess with timing. PITA.
 

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Load Bearing Member
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...I've rebuilt more than a few, but with this distinction- they were made by Varian, and they weren't used in boats, that I know of.)
¬Erindipty
If they were made by Varian, I would doubt they were on an engine.

Their 'turbos' are vacuum pumps.

AFAIK

Ken
 

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Beyond The Pale
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If they were made by Varian, I would doubt they were on an engine.

Their 'turbos' are vacuum pumps.

AFAIK

Ken
Ayup. The principles are the same; get the speed of the Vanes up to a high enough speed so as to direct Molecular Flow. With these Varian Turbopumps, I routinely logged Driver Current and Bearing Temperatures; if there was a sudden sharp rise unrelated to Pressure, the pump was removed for new bearings. They had hundreds of Varian Turbos to keep an eye on.
I've also rebuilt quite a number of Varian and PE Ion Pumps. Instead of simply replacing the Titanium and/or Tantalum Elements, as Varian and PE did at great expense, I literally beat the crap out of them, using a particularly peculiar form of Sandblasting.

But this has little to do with the ongoing discussion, so I shall end it here.

¬Erindipity
 

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Discussion Starter #9
So the thing will run which is good to know. Question remains with enough hp to adequately move the boat. From the above helpful and appreciated posts. Abstract
May not fail catatrophically
May or may not destroy the rest of the engine. My concern is on passage as coastally you can just right a hurtful check. Specific question is blown turbo and need for several days of powering - what does that do to the engine?
Hp will decrease but how much? Yes Martha you do get waves even in the absence of wind sometimes and it's nice to stay ahead of the front and have an engine to get through that cut when you get to where you're going.

Btw emailed yanmar same questions as original post. Still waiting for an answer. Will share it if they respond.

Glad to hear naturally aspirated diesels are available. Haven't seen one in a new boat in quite some time. Maybe people wouldn't accept the extra weight to get to the same hp or the naturally aspirated version won't fit. Think it common to spec the lowest hp to adequately serve intended use due to weight and expense. I have 75hp on a 30k lbs. boat and think that adequate. Think less would not be.
 

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al brazzi
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I think if I had one I would replace the turbo around the factory recommended interval and save the old one as a spare. All the debate on whether it will run without can be summed up by "Not well if at all" But then I wouldn't own one at least if there was a choice.

The reason they are so prevalent is HP/weight ratios and simply to sell them. Cars are made to showcase the new tech to create a market for new tech. Ever driven a new Cadillac with the 4 cyl turbo, try it you'll like it.
 

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Another issue with turbo failure is that if it is a dramatic failure small parts of the compressor blades, housing and or bearing can be sucked into the engine, doing lots of harm. Mostly happens with higher RPM turbo motors but I suppose it could happen with any turbocharged motor. Miniwaska has issues with his turbocharged engine I believe, so perhaps he will chime in about what happened to his. But it really depends on the failure point as some exhaust should be able to get around the vanes to get out and fresh air can get in, so it may run to a fashion, but more like limp home to the port, not finish a long passage. I believe the largest normally aspirated diesel you can get anymore (for a normal sailboat) is going to be around 75 HP for a Beta, but you can put a much smaller engine with a turbo to get the same power, that is often a deciding factor. I certainly would prefer the mechanical simplicity of a normally aspirated mechanical injected engine.

A bigger issue with the modern high fuel pressure diesels, (common rail) likely of greater issue for a cruising boat(you could carry a spare turbo they are not that big, and easy enough to replace in the field), is the fuel systems are very sensitive to fuel quality and cleanliness. If you ruin a modern high pressure fuel pump you are looking at replacing the entire fuel system (on VW's they even replace the fuel tank and all fuel lines injectors, filter units, the whole kit and caboodle) and that would be quite a bit harder to cope with in a remote port. The Bosh pumps have not proven to be terribly reliable, and I have not read about the exact cause, some say moisture causing corrosion, others say dirt, while even others just blame poor fuel, with incorrect additives.
 

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al brazzi
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And don't forget the heat. I've seen turbo's on big Generators get red hot, you can see the cooler air swirl around as it gets heated up.
At least on an NA the heat goes out the mixing elbow right away.
 

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Discussion Starter #13 (Edited)
Wow

Good thing the d-mm thing has sails.

Fortunately I have have the TE 75 hp not its replacement the 80hp digitally controlled common rail one. Sometimes progress is not progress for all.

Don't have true polishing system but do have filters in run from tanks and on return to tanks as well as the usual twin Racors and the filter on the engine.

They have portable polishing systems both down in the islands and up in the north east. Is it advisable to get this done and if so at what intervals.
 

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Beyond The Pale
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Wow
Wow

...
They have portable polishing systems both down in the islands and up in the north east. Is it advisable to get this done and if so at what intervals.

"Polishing" is something of a recent Trend, with a profitable Trendy name...
When I bought my most recent boat, I had no idea how long the Diesel fuel had been in it, so I drained it all out, and put it in the tank of my Mercedes Tank, where it cheerfully Dieseled away in a month or so. Good Diesel.
Fresh Diesel fuel was put in the Boat, but only 5 gallons. 5 gallons lasts me a long time.

There are those that insist on huge Diesel tanks, just like those used in Trendy Diesel Powerboats... on a Sailboat. A... Sail... Boat...

If one has a Sailboat with a full hundred gallon Diesel tank, and one has goals that involves burning that hundred gallons in a month or so, Polishing is not needed.

If one has a Sailboat with a full hundred gallon Diesel tank, and one has goals that involves sitting Dockside, waiting for just the right time to take off on short notice, if ever...

Polishing: "There's a sucker born every minute."

¬Erindipity
 

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Discussion Starter #15
Guess we use our boats differently.

Twice a year I have 1500+ nm to cover. I have done it with the Salty Dawgs. So far there have been days of no wind and days of gale force wind. Still we go through a lot of diesel on the no wind days. It's common for folks with inadequate tankage to divert to Bermuda to get fuel.

Yes it's a sailboat and both when coastal in New England or island hopping the main problem is leaving the diesel on long enough to heat up but on passage there are days it doesn't go off. From talking with other cruisers be they hopped down the west coast and done the canal or started in Canada it's the same thing. Two passages with days of engine use then two blocks of months of little or no engine use. Especially given you can even sail off your anchor not uncommonly.

Gone to Bermuda multiple times with no engine use because we were racing. But cruising you want three or four on the boat and at least one of them has a time window. Or you're watching the weather and know you need to make your easting now or get below this latitude ASAP to miss the nasties coming at you three days from now. So this purist attitude of "it's a sailboat " loses its appeal and the engine goes on.

Reviewed our quick books for last year looks like ~110g down, ~80g back,~ 45g winter, ~55g summer. So burned ~190g in 20d(passages) and ~ 100g the whole rest of the year. Fuel up here is fine. Even comes with biocide in it. Fuel down there ?????? So I ask about polishing.
 

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al brazzi
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Unless already in service one day soon we MAY deal with Urea (DEF) on boats emissions requirements for Marine AFAIK are not there yet. Someone can check me on this I deal with big Trucks and Fueling so DEF is a big deal lately.

On the polishing issue we all polish through the normal return to the Tank every time the engine is running. How much is the question. Every system is different. A polishing system would ideally pull from the bottom on one end and return to the top on the other end, but again unless the fuel sits unused for a long time there's no need. One nice thing is you could notice a water issue before the engine does because the polisher would pick up lower than the engine. Of course this is all things being equal on a stationary tank.
 

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Discussion Starter #17
Well Al good to know. Just another reason to be real kind and attentive to your engine. They charge a lot for piss and you need to be real careful the piss is fresh piss or it fouls up the engine. Believe for many car diesels it has an effective shelf life of only 90 d which may be a hassle if we are forced to use it in boats.
 

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Discussion Starter #18
Hi ......,

If the turbo fails the engine will idle at best with smoke due to limited amount of air entering the engine.
Yes you can change it at sea. Make sure to have all the gaskets and clamps.
Any debris from a turbo failure can cause internal damage to the engine.

Please contact me direct for any further assistance,

Capt. John J Farrell
Product Support Specialist

MACK_Color-EMAIL

Reply from yanmar/Mack Boring
 

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Old enough to know better
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Well Al good to know. Just another reason to be real kind and attentive to your engine. They charge a lot for piss and you need to be real careful the piss is fresh piss or it fouls up the engine. Believe for many car diesels it has an effective shelf life of only 90 d which may be a hassle if we are forced to use it in boats.
I think the VW urea tanks need to be filled every 15,000 miles so I imagine the shelf life is a bit more than 90 days. But the timing is aligned to match the oil change interval.
 

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Discussion Starter #20
Discussed this with my jeep wrench. What I said was "effective " shelf life. Given average miles miles driven the stuff will sit in your car for awhile so poring in DEF more than 90d old is not advisable.

Also told there is a wide variation in the quality of DEF. Best to use oem for a few $ more if you are going to hang on to the vehicle but still check the date on it.
 
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