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-   -   To turbo or not to turbo? (http://www.trawlerforum.com/forums/s6/turbo-not-turbo-29477.html)

Bruce B 12-18-2016 01:58 PM

To turbo or not to turbo?
 
OK,
I'll begin this.
It appears that we have proponents of turbochargers and we have people who dislike the very thought of their existence!
Where do you stand and why?
Having begun my career in automobile repair back in the early 1980's working as a Saab mechanic I had some fun exposure to those early Garrett T3 units bolted to the 1978 and later Saab Turbo. I maintained them and I repaired them including more than a few bench rebuilds.
They are pretty simple things really. Good oil changes and proper use went a long way to making them nearly bulletproof. I've also worked on a pile of VW 4, 5 and 6 cylinder turbo Diesel engines.
I found that like most mechanical systems, turbo engine lifespan comes down to use and maintenance first. The same things that lead to turbo engine demise will hasten any engine towards its end of life.
I've seen people who could destroy a Toyota Corolla in just a few years and I've seen people who could milk 200,000 out of a 1970's GM/Olds diesel.
I vote that turbos are fine.
What say you?

MurrayM 12-18-2016 02:14 PM

I'm a slope foreheaded, uni-browed, knuckle dragging lout when it comes to mechanical things, so I read the manual for our Yanmar 4JH2-UTE engine.

It gives instruction on how, if running at a fast idle for a prolonged period, to run it at a faster rpm for a certain length of time...I'm assuming this is to clean the turbo, among other things...

Would idleing for prolonged periods, such as battery charging or trolling for salmon, be a major reason why turbos fail?

Looking forward to more in depth answers.

Bruce B 12-18-2016 02:25 PM

Quote:

Originally Posted by MurrayM (Post 505316)
I'm a slope foreheaded, uni-browed, knuckle dragging lout when it comes to mechanical things, so I read the manual for our Yanmar 4JH2-UTE engine.

It gives instruction on how, if running at a fast idle for a prolonged period, to run it at a faster rpm for a certain length of time...I'm assuming this is to clean the turbo, among other things...

Would idleing for prolonged periods, such as battery charging or trolling for salmon, be a major reason why turbos fail?

Looking forward to more in depth answers.

Running any Diesel engine for long periods without "proper" load is bad for the engine, turbo or no turbo. We used to have to charge batteries on our sailboat (40 hp Yanmar) and I hated doing it! I finally found a way to install a proper 4 kW generator for charging and air conditioning duties...

By the way, the manual for our 40 hp naturally aspirated Yanmar used the same language about running at higher speeds after extended no load operation.
My answer was to run it hard when we were actually using it for propulsion.
Bruce

djmarchand 12-18-2016 02:26 PM

Well, the question is becoming moot, as you can't buy a non turbo engine today from a major manufacturer unless it is under 100 hp.

And I guess the beef if any with turbo engines is that they produce too much horsepower for the size. An older Ford Lehman or Perkins 6.354 is limited to 135 hp from its 5.8 liter engine with no turbo.

Today you can get 450 hp or so out of the same dispacement with a turbo and sea water cooled after cooler.

It isn't the turbo per se that is the problem with these engines, it is the high horsepower output and the associated after cooler failures that breaks them.

But if you keep the horsepower down to reasonable levels, turbos are no problem. One of the best medium horsepower engines available is the Cummins 210 hp 6BT with no after cooler.

Another factor that gives turbos a bad rep is salt water. I see lots and lots of reports of the owner replacing his turbo and assuming that this is something you just have to do. Well you don't usually replace turbos on auto or truck engines even after 10,000 hours. But owners do it all of the time on marine engines, usually because a lousy exhaust system allowed sea water to back up into them.

So, turbos are fine. It is all the baggage that goes with them that isn't so good.

David

Bruce B 12-18-2016 02:34 PM

David,
The exhaust system is the subject of much verbiage on the Seaboard Marine website. Apparently, many, many boats are built with flawed exhaust systems.
It is actually interesting reading material.
I am a maintenance kind of guy so I will be keeping an eye on the aftercoolers in our new Cummins QSB and I will surely disassemble them and lubricate seals the minute it gets home!

I've said it before, so many boat owners keep their equipment in such poor shape that I am amazed that boats run at all!
Maintenance is key! Then most other failures should come down to acceptable levels.
Bruce

Bruce B 12-18-2016 02:56 PM

1 Attachment(s)
On the subject of maintenance, my last marine diesel, pictured here at 10 years of age and at about 1800 hours, saw the following annual maintenance...

Replace engine oil and filter.
Replace fuel filters.
Replace alternator drive belt.
Replace raw water pump impeller.
Adjust valves.
Remove and inspect exhaust riser.
Check all raw water hoses and clamps.
Disassemble and clean engine heat exchanger.
Replace thermostat (every second or third year)
Drain antifreeze and replace.
Inspect all electrical connections in engine harness.
Wash engine with Roll-Off and water.
Run engine until dry and then spray entire engine down with WD-40. Wipe down
engine surfaces of excess WD-40.

This was my normal engine to-do-list, every year.
The picture of our engine was taken midway through a 6 week trip to Maine. This is the way it looks all of the time. No rust, no leaks no issues. Most people say it looks better at 11 years of age than a typical 1 year old boat.
I like leaving nothing to chance but I do not believe that a turbo would have made any difference in this engines reliability.
Bruce

eyschulman 12-18-2016 03:09 PM

Quote:

Originally Posted by Bruce B (Post 505319)
David,
The exhaust system is the subject of much verbiage on the Seaboard Marine website. Apparently, many, many boats are built with flawed exhaust systems.
It is actually interesting reading material.
I am a maintenance kind of guy so I will be keeping an eye on the aftercoolers in our new Cummins QSB and I will surely disassemble them and lubricate seals the minute it gets home!

I've said it before, so many boat owners keep their equipment in such poor shape that I am amazed that boats run at all!
Maintenance is key! Then most other failures should come down to acceptable levels.
Bruce

The exhaust SX issue hits the nail square on. The other issue is not allowing a turbo a cool down at lower rpm after hard running. All other issues are pretty much routine engine maintenance. Most trawlers which invariably are equipped with bigger engines than needed and are running below hull speed may not even engage the turbos which are usually designed to kick in at higher load. SD hulls that can travel faster will benefit from the larger turbo engines where the turbo will kick in and give extra boost at the higher speeds.For ecology and power output reasons new motors have or will soon have turbos unless you go low hp and that may also change soon. Best to learn what you need to know about the units because like computers it will be hard to avoid them.

Lou_tribal 12-18-2016 03:25 PM

As you ask for opinion I will give!
About cars first... No turbo,never, ever! The problem with turbo is the rpm. When you are low rpm you don't have any power at all. If you drive a turbocharged car you need to be sure to always be high rpm as if you go low you loose all the power. I am not professional driver at all but sport car lover. I love the flat 6 in my car, it kicks your ass at any rpm, no need for a turbo. Not a general rule but usually turbocharger are used for emission rules and try to compensate underpowered engines.
On trawler now. Don't think the same apply as the need for power is really not the same. Turbocharged marine engine are a way to have smaller engine delivering the needed power and meet emission regulations. However for me it is also introducing a failure point in the equation. Is it really needed, I do not think so. Do you really need 500 hp on a trawler? It depends on the boat but for mine my straight old naturally aspirated 6 is doing a great job and far enough for the need. I saw some trawler running on 60hp or 70hp and they were going nice and slow like it should be.

Bay Pelican 12-18-2016 03:36 PM

Turbo or non-turbo. Like everything else on a boat it depends on what you are going to use it for. A turbo when you are running the ICW on the east coast of the US, or daytripping out of any harbor is one thing. A single engine turbo crossing an ocean is one more thing that can break.

My preference is simplicity when crossing oceans. I have a Yanmar wing engine that can be started with a hand crank.

Bruce B 12-18-2016 03:48 PM

Quote:

Originally Posted by Bay Pelican (Post 505328)
Turbo or non-turbo. Like everything else on a boat it depends on what you are going to use it for. A turbo when you are running the ICW on the east coast of the US, or daytripping out of any harbor is one thing. A single engine turbo crossing an ocean is one more thing that can break.

My preference is simplicity when crossing oceans. I have a Yanmar wing engine that can be started with a hand crank.

So here is an argument for simplicity.
I've started Yanmar QM series with a hand crank and although it started, it wasn't easy and I'm not sure that with my damaged rotator cuff I could do it today...

I do understand the argument for simplicity though as if it isn't there it can't break can it?
Bruce

psneeld 12-18-2016 03:52 PM

While I am not worried about turbos..having run many thousands of hours with and without them....

I have had one failure on a brand new Cat where it threw a blade on a a trip to the fuel dock for a delivery to the new owner the next day.

I also had a Cat Aftercooler that leaked into the 5 and 6 cylinders and it needed a rebuild, that was on a delivery. CAT had a class action lawsuit for those after coolers and made good...but the engine still needed rebuilding and delayed the delivery for a month.

So I do agree that more pieces equal more chances of failure, I see these failures being the equivalent to being hit by lightning.

I know some here like to risk manage to the point of nearly not getting underway...but turbos and their systems if maintained are not a likely source of being stopped dead in your tracks.

BandB 12-18-2016 04:05 PM

Turbo. For me, it's very simple.

I've never owned a diesel that wasn't turbo. I've never had any issues with a turbo engine. They only manufacture turbo engines in the size and for the boats I want. Simplicity.

Seevee 12-18-2016 04:15 PM

Bruce,

Thx for starting this thread.

As for me, I'm in the camp where I don't want one on most any engine. It's just one more failure point and does need maintenance.

Most of my turbo experience is on aircraft, and my Marine experience is minimal. In the aviation world turbos offer a LOT of performance that you just don't get without one. A lot better climb and altitude capability, and once higher up, more speed. They typically last about 1500 hours and you rebuild them for perhaps $3 to $4K, so they are not horribly expensive.

But they do have a higher failure rate. Wheel failures, oil line failure, oil pressure failure, and occasionally the failure can be exciting with fire in the engine compartment. These things are HOT, and a oil line bursting over a hot turbo is not fun. I've had 4 turbo chargers on planes and only one failure which was an oil line breakage, but a non event. (aviation mechanic and pilot).

For cars I've had one, inherited it, from mother in law, immaculate but pricey. Son in law destroyed it in a month, burned up the turbo.

My boat experience was with friends 450 Sundancer, with cats. I spend a lot of time on it and helped with the maintenance. The turbos needed TLC and one had to watch them. Caught a clamp loosening up a bit, but no major issue. I couldn't imagine operating one without an intercooler.... that compresses air is awful hot.

Overall, I'd MUCH rather have a bigger engine instead of a small/turbo'd one. Seems like operating the turbo at slows speeds has more issues that a larger engine, do I get that right?

However, seems like an awful lot of marine diesels do have turbos. I don't understand how the turbo allows for a better EPA profile, can someone explain that?

kmacdonald 12-18-2016 04:20 PM

It depends on a lot of factors and the answer will be yes sometimes and no in other situations. It comes down to application.

MurrayM 12-18-2016 04:22 PM

Quote:

Originally Posted by Bruce B (Post 505317)
Running any Diesel engine for long periods without "proper" load is bad for the engine, turbo or no turbo. We used to have to charge batteries on our sailboat (40 hp Yanmar) and I hated doing it! I finally found a way to install a proper 4 kW generator for charging and air conditioning duties...

By the way, the manual for our 40 hp naturally aspirated Yanmar used the same language about running at higher speeds after extended no load operation.
My answer was to run it hard when we were actually using it for propulsion.
Bruce

We don't charge at idle either, or troll for salmon. Our electrical needs at anchor are small, and battery charging is much faster now while underway after getting a larger alternator and cables.

Engine is nowhere as squeaky clean as yours, but is running great.

Bruce B 12-18-2016 04:28 PM

Quote:

Originally Posted by BandB (Post 505338)
Turbo. For me, it's very simple.

I've never owned a diesel that wasn't turbo. I've never had any issues with a turbo engine. They only manufacture turbo engines in the size and for the boats I want. Simplicity.

That is simple!
We are in the same boat, so to speak, at least as we look forward.
Plus, I kind of like the whistle of a turbo under boost.
Bruce

Fletcher500 12-18-2016 04:29 PM

1 Attachment(s)
If turbo's were a reliability issue, they wouldn't use them on these.

Bruce B 12-18-2016 04:45 PM

Quote:

Originally Posted by MurrayM (Post 505343)
We don't charge at idle either, or troll for salmon. Our electrical needs at anchor are small, and battery charging is much faster now while underway after getting a larger alternator and cables.

Engine is nowhere as squeaky clean as yours, but is running great.

The Cummins in our new boat is white. I'm going to have to up my game! That Yanmar is "squeaky clean" though...
It makes me happy!
Bruce

BruceK 12-18-2016 05:00 PM

Quote:

Originally Posted by Lou_tribal (Post 505326)
As you ask for opinion I will give!
About cars first... No turbo,never, ever! The problem with turbo is the rpm. When you are low rpm you don't have any power at all. If you drive a turbocharged car you need to be sure to always be high rpm as if you go low you loose all the power....
On trawler now. Don't think the same apply as the need for power is really not the same....
Do you really need 500 hp on a trawler? It depends on the boat but for mine my straight old naturally aspirated 6 is doing a great job and far enough for the need. I saw some trawler running on 60hp or 70hp and they were going nice and slow like it should be.

As to turbo cars, disagree, my turbo diesel car has heaps of torque and power and response down low. Plenty of (non exotic)performance cars have a diesel option.
As to boats, agree. I`d rather a big slow revving naturally aspirated diesel than a high rpm turbo diesel, it`s just another layer of maintenance and potential for trouble. But, as said above, for new engines, no non turbo option.

BandB 12-18-2016 05:17 PM

Quote:

Originally Posted by BruceK (Post 505358)
As to turbo cars, disagree, my turbo diesel car has heaps of torque and power and response down low. Plenty of (non exotic)performance cars have a diesel option.
As to boats, agree. I`d rather a big slow revving naturally aspirated diesel than a high rpm turbo diesel, it`s just another layer of maintenance and potential for trouble. But, as said above, for new engines, no non turbo option.

Wifey B: My turbo car has power at all rpm's. 530 hp or so, 0 to 60 in 3 seconds. :)


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