Lifespan of Diesel Engines

[roryon33]

Hi
Whats the general lifespan in engine hours on say a 200hp volvo or yanmar deisel engine if its serviced?

Yanmar, Volvo, Mercruiser - which would be the most reliable in the diesel market?
Thanks

 

[Koeketiene]

Well maintained diesel should last at least 4000hrs - many last longer.

Yanmar & Vetus (now Mitsubishu based) have a good reputation.
Yanmar spares available pretty much worldwide.

 

[ambientmarine]

If it's serviced properly using the right oils and by a mechanically competent person, I would expect around 20 years of average use, ie, 2-3 months a year. In engine hours no idea.
The most reliable diesol isn't one of the above, volvo being the most unreliable in my experience, I would prefer to use one of the automotive conversions such as the Ford/BMC/Perkins units, there are examples of these being run for years without repair or major works. I've just changed a 25 year old BMC for a more recent example. Automotive engines in the region of 80hp are designed to run continuously for millions of hours. They just need the right attention!

 

[tangofour]

Perkins 4108 50hp 20 years 5500 hours and still going strong /forums/images/graemlins/ooo.gif

 

[pvb]

[ QUOTE ]
Automotive engines in the region of 80hp are designed to run continuously for millions of hours.

[/ QUOTE ]Perhaps that's just a little optimistic!

 

[oldsaltoz]

<<<would expect around 20 years of average use, ie, 2-3 months a year>>>

We have been running around 500+ hours a year, mind you we are 'in' the water for the full year but for one lift out to clean, inspect, replace anodes and antifoul then back in the next day.

20 years x 500 hours = 10,000 hrs plus or 6 engines at 4,000 hours each (we have twin Volvo's). so around 15 tonnes of fuel as well.

Something tells me my little green monsters will not last that long. We plan to install the yellow peril next.

Avagoodweekend......

 

[fisherman]

My Ford Dover (Mermaid) had 14000 hours on the clock when it developed a crack next to a core plug. It was stripped for the Insurance company, and they agreed no significant wear, total replacement.

Mermaid say that an engine is done when oil consumption is 2% of fuel consumption.

 

[Lakesailor]

An engine is knackered because of valve guide wear or a broken ring?
Bit simplistic isn't it?

 

[mortehoe]

I rebuilt a 20 year old Yanmar 1GM10 overwinter. It took longer to haul the engine out than it took to rebuild it and reinstall it (2 new rear mounts rqd)

The cranking compression when hauled was 295 psi - the engine had to be started with eeeezy-start ether or something like that and it still took a long time to get from chugg-ugg-ugg-pop repeat for 4 minutes till it went smiley bm-bm-bm-bm ..........

When rebuilt with genuine Yanmar parts at a total Ebay cost of £166.00 inc postage the cranking compression was 420 psi ... and when fuel was admitted to the system it went very rapidly to brrrrrrrrrrrmmmmmmmmmmmm.... and was shut down as quick as quick can be as it was a dry run.

What was interesting, (~2250 hours on the engine was that the new piston was a 'standard' piston and that the new rings were 'standard' rings ... ie the wear on the bore over 20 years was less than 0.0007mm in both directions; the wear on the gudgeon pin was 0.004 as was the wear on the big end.

Reason for change & rebuild: One of Yanmar's major faults is admittance of water into the cylinder(s) if you overcrank = a shortened con-rod by at least 1.2mm!!! ..... My next engine will be a Beta after this last-winters labour of love attending to an ancient agricultural machine .........

 

[Birdseye]

[ QUOTE ]
If it's serviced properly using the right oils and by a mechanically competent person, I would expect around 20 years of average use, ie, 2-3 months a year. In engine hours no idea.
The most reliable diesol isn't one of the above, volvo being the most unreliable in my experience, I would prefer to use one of the automotive conversions such as the Ford/BMC/Perkins units, there are examples of these being run for years without repair or major works. I've just changed a 25 year old BMC for a more recent example. Automotive engines in the region of 80hp are designed to run continuously for millions of hours. They just need the right attention!

[/ QUOTE ]

These days, they are all automotive conversions of one sort or another. Most small ones are earthmoving / small tractors, whilst the bigger ones are truck / car.

"Automotive engines in the region of 80hp are designed to run continuously for millions of hours." times an average of say 20 mph = 20 million miles? You might expect half a million miles out of a trcuk engine but cars will do well to exceed 200k.

Its really down to the type of use rather than hours or miles. The prob with boat engines in sailboats is internmittent short duration use, so dont expect automotive style lives.

 

[fishermantwo]

My Gardner 6lw is 72 real horse power, ship loads of torque. Probably 65 years old. Still works hard and is still all original. I don't work as hard as I used to, probably only 800 hours a year now. Up until about 4 years ago probably worked 2000 hours a year at least.

 

[fisherman]

They insisted on an inspection because if the engine was deemed to be well worn they would not have payed the full replacement cost, I would have had to pay a proportion.

 

[Andrew_Fanner]

My HT6354s are 37 years old. Bit grubby and smoky but start instantly. Hourmeters allege 1300 hrs which seems far too low.

May have been rebuilt mid 1990s but no documentary proof.

 

[PaulJS]

Hi, my CV implies that I should know a bit about this, although generally on slightly bigger engines. All I can add to the previous advice is to use the best oil, cleanest fuel, reputable manufacturers filters, let the engine idle until just warm, and perform services regularly (but don't worry if a few hours over intervals). Older engines were usually "over-engineered" and so can last longer while modern engines are manufactured to finer tolerances with greater understanding of the materials behaviour and limits and electronic management systems which can increase their reliability and increase service intervals! Basically if you look after a diesel it will look after you.
Having said that, I always carry out planned maintenance on my ships religiously.... generally on my knees facing east with hands together to cover all eventualities! /forums/images/graemlins/grin.gif
And now I've started sailing, /forums/images/graemlins/smile.gif ! Windpower is definitely more enjoyable!

 

[TheBoatman]

I think 4000hrs is a bit on the under-estimated side unless you treat it badly.

The original poster wanted an average/estimate and FWIW I'd say 10,000hrs if the engine is serviced reasonably regularly.

I've always found that it's the yottie that insists on sailing right up to his mooring and only using the engine for the last few yards or who uses it to "charge" his batteries that has the most problems with breakdowns.

The best thing you can do for your diesel engine is to work it, but don't thrash it and service it when it needs it. I say "when it needs it" because IMHO a diesel that's only done 50 - 60 hrs doesn't need a service even if it has been a year doing it ~ leave it alone.

Do the sums?

Average boat/engine use ~ 50 hrs x 5knts = 250nm @ 2,5 litres/hour = 125ltrs.

My diesel car.
Service interval = 30,000 miles
Average fuel consumption @ 40 mpg = 750 galls OR 3375 litres.

Big, big difference.

As far as the engine is concerned what is changed ~ fuel filter, oil filter and oil.

Now think of it this way ~ if we start with the 3375 litres and work backwards!

We get ~ 3375ltrs div by 2.5 litres/hr = 1350 hrs or 6750nm or a service interval on the engine for a boat averaging 50 hrs @ 5 knts of every 135 years /forums/images/graemlins/tongue.gif

Don't recommend it ~ but I hope you see my point!

Just one last thing ~ If my yacht engine was a car engine then it would take me 8.04 weeks of motoring at 5 knts to go from service to service.

So why do the marine engine manufacturers recommend a 1 or 2 hundred hours or annual service ~ could it be because they want to make a profit on the spares?

Peter.

 

[oldharry]

Road vehicle engines have a very different life to marine engines - particularly yacht auxiliaries. Road engines are subjected to a lot of acceleration/decelleration cycles, varying loads, and demands. Marine engines as a rule run at constant speeds sometimes for many hours at a time without the stresses of rapid accelerations. They therefore tend to last longer, except that they live in a much more hostile environment of damp and salt in the bilges of the boat.

The old saying that boat engines don't wear out, they rust away, has a lot of truth. I have just removed a 35 yr old Yanmar with virtually no wear on the bore. Thats the only good bit of it! The rest of it has suffered from years of damp ingress, including the fuel system.

As a notional guideline a car can be said to average 40mph during its life time. Someone commented most cars fail before reaching 200k miles, but that is usually the fault of the MOT tester, not the engine itself. In any case people who run 'hi-milers' tend not to look after them, neglect oil changes and proper servicing so the poor old engine doesnt have a chance. I know of taxi drivers who regularly run cars happily well beyond that mileage without problems, thanks to meticulous servicing.

So an engine with 5000 hours on it can be equated to a car with 200,000 miles on the clock. But because of the different type of demands, if its looked after, there is no reason why the boat engine should not plod on to 8,000 hours or more.

I think most manufacturers would be wanting you to look at a major overhaul at 5 - 6k hours though. That would be roughly 2 years running 8 hours per day, which could be doubled with meticulous servicing. Very few leisure boaters can run up that sort of mileage in a hurry!

 

[Guest]

My Mercedes 814 Truck .... with 6 litres of Merc. Diesel engine has 660,000 Km on the clock. It had a rebuild a while ago when I lent it out to a "friend" who ran it all day without oil or water ... despite being shown / asked to keep an eye on it ... (We were waiting for replacement radiator to arrive ... engine went Hot ... oil burnt away ... engine went bang ...!)

BUT when the engineers stripped the engine ... they found that most was ok and not needing replacement ... the original block and liners were used etc. etc. etc.

660,000 KM .... and she goes like a good'un.

My boat engine apart from cahnging the pump due to guv'nor problem ... is maybe near 40 yrs old ... still going strong.

 

[oldharry]

Nice one, and proves my point - regular careful servicing blah blah blah!

Now you're going to tell me you never touched it .... /forums/images/graemlins/smile.gif

 

[bluedragon]

Probably doesn't help you a bit because they don't make 'em like the used to, but my trusty Sabb 8HP is 38 years old, god knows how many hours of use, no smoke, no loss or usage of oil throughout the season, and will probably go on longer than me! The problem with more modern engines I think is they are lighter (less iron) and corrode more quickly to an end point.

 

[Guest]

[ QUOTE ]
Nice one, and proves my point - regular careful servicing blah blah blah!

Now you're going to tell me you never touched it .... /forums/images/graemlins/smile.gif

[/ QUOTE ]

How did you guess ? True ... my boat engine had its 1st oil change in 4 yrs this winter. Old oil was not that bad when it came out - but filter was shot !

The truck having had the rebuild is looked after better - but once its had 2 or 3 changes - then it will be on SBC schedule ...