Small Diesel engine life-span - 120hp and 165 hp

[wildwords]

Hi guys

Eventually we have narrowed our search to a few possible vessels around our budget, but the reliability and life-span of the diesels is a bit of a question. If we go for a diesel we want it to last the 200 -300+ hours we will put on it annually for a minimum of 5 years. Of course we will maintain it to the letter etc.

If anyone has any experience as opposed to pillow talk on the engines below and their likely realistic life-span, their opinion would be greatly appreciated.

Engines

1998 Yamaha ME370STI 165HP (800) hrs done - driving a 7.4m redbay

2002 Mercruiser 1.7dti 120 hp (400) hrs done - driving a 6.5m humber

2006 Volvo D3 130 hp with 30hp chip ( 400) hrs done - driving a 6.3m humber

2007 Mercruiser 1.7dti 120 hp ( 200 ) hrs done - driving a 6.3m parker

Many thanks

Emo

[willk]

In his article (somewhere on here) John Price proposed that the average lifespan of a diesel inboard was c.1500hrs, depending on useage etc.

Your application will involve very low revs for a lot of the time and I think this should squeeze a few more hours. In fairness, he was suggesting 1500hrs as the time they started to have major failures.

[Mollers]

It's a bit of a 'peice of string' question. A lightly loaded, meticulously maintained deisel could go on practically forever. I had a 2.5ltr BMW that did 300k miles on regular servicing and a set of heater plugs.

However, a 1.7ltr lump in a 6.5m rib is going to be far from 'lightly loaded'. I'd go for as big a lump as you can sensibly find. A lazy big deisel probably wont burn as much fuel as a flogged tiddler.

[doggypaddle]

Originally Posted by willk

In his article (somewhere on here) John Price proposed that the average lifespan of a diesel inboard was c.1500hrs, depending on useage etc.

Your application will involve very low revs for a lot of the time and I think this should squeeze a few more hours. In fairness, he was suggesting 1500hrs as the time they started to have major failures.

Surely that incorrect? 1500 hours? thats equivalent to 45,000 miles in a car! Most diesels I have worked on wouldn't be considered fully run in at 1000 hours. our hire boats used to clock up over 1000 hours a year, and my mates tractor clocked up 12000 hours in 4 years,
The generator outside iceland in Monmouth ran for a year continuously,
thats 8000 odd hours!
in my plant experience we found heavily used plant engines generally got tired at 10-20000 hours, and generally got run out of oil by hirers, so were murdered rather than popping their clogs from naturel causes

wern't the lister generators sold to trinity house specced to run 52,000 hrs(six years) continuous ?

obviously engine load makes a big difference, and boat engines tend to be heavily loaded, but conversley in a vehicle application its the stop start that wears them out, marine engines tend to be more constant speed use and stopped/started less?

[doggypaddle]

i wonder how many ways diesel will be spelt by the end of this thread
we have 2 ways so far

[willk]

Personally, I have no idea if it's correct. I would stress that we're not discussing gp diesel engines, but rather small marine units. These are generally producing much more power than the original design allowed for. I'm guessing that the leg is included in the equation.

The opposite would be a 1500rpm "continuous/prime" genny, designed to run for ever...

Think about the 1500 hours though. What is the life expectancy of a small marine diesel, or indeed, medium sized outboard in hours?

100 hours a year for 15 years....?

[HUMBER P4VWL]

No actual experience, however willis estimates sound realistic. Two factors to also think about when estimating lifespan:
1. Boat engines generally float about on salt water as opposed to generators in dry sheds.
2. Like cars. 1000 hrs could be done oner 2 years or 10 years. The former is kinder due to less engine use at cold.

[willk]

Originally Posted by HUMBER P4VWL

however willis estimates sound realistic

Not my estimate but rather that of John Price.

Maybe not the day to call me willi either, thnx

http://news.bbc.co.uk/2/hi/americas/8535618.stm

[Erin]

Originally Posted by doggypaddle

i wonder how many ways diesel will be spelt by the end of this thread
we have 2 ways so far

Depends if gArf joins in

[Mollers]

Originally Posted by doggypaddle

i wonder how many ways diesel will be spelt by the end of this thread
we have 2 ways so far

Duckin Fyxlexia is a Bsatrad.

[Mollers]

Originally Posted by doggypaddle

but conversley in a vehicle application its the stop start that wears them out, marine engines tend to be more constant speed use and stopped/started less?

Yes, but the lack of gears in a marine application applys loadings which would be avoided in a geared vehicle. Labouring an engine is as detrimental to it's long term health as cold running and over reving IMV.

[willk]

Originally Posted by Mollers

Duckin Fyxlexia is a Bsatrad.

yew tukk dat crittercysm kwite welle, i thort

[deezil]

[Mollers]

Originally Posted by willk

yew tukk dat crittercysm kwite welle, i thort

[deezil]

I hope I only visit the Ribnet Dyslexia Club on occasions as the founder member and I rarely see I2I.

[doggypaddle]

Originally Posted by Mollers

Yes, but the lack of gears in a marine application applys loadings which would be avoided in a geared vehicle. Labouring an engine is as detrimental to it's long term health as cold running and over reving IMV.

You aint seen my driving.
I change down when I can hear the engine going 134213421342 and puffing black smoke rings out the exhaust with each power pulse, and change up when the pistons get out and do a little irish jig on the bonnet

[doggypaddle]

according to boat safe.com 8000hours
they do say they dont last as long as automotive engines though......


"Diesel engines are built to finer tolerances than are gasoline engines. They will accept much more abuse and often deliver, if well maintained, 8,000 hours of hard work before need a major overhaul. Theoretically, a well-maintained diesel may last the life of your boat. Since the average recreational boater logs only about 200 hours per year, the 8,000 hour diesel would last 40 years"

[Mollers]

Originally Posted by doggypaddle

according to boat safe.com 8000hours
they do say they dont last as long as automotive engines though......


"Diesel engines are built to finer tolerances than are gasoline engines. They will accept much more abuse and often deliver, if well maintained, 8,000 hours of hard work before need a major overhaul. Theoretically, a well-maintained diesel may last the life of your boat. Since the average recreational boater logs only about 200 hours per year, the 8,000 hour diesel would last 40 years"

Unfortunately, it's the extended periods of non-use with a recreational craft that tends to do the damage.

[Bigmuz7]

I agree with much of what has been said, I maintain various diesels up around 10000 hrs, in regular use and have restored old vintage ones that in many cases require only minor wear parts ,.. these are engines that are 50 years old, and will still happily do a days work .. admitadly there lives have not been hard ones but I'm still impressed how long they have worked, in some cases with nothing more than good regular servicing. They might be noisier and less efficient, but by and large technology hasnt changed a lot over the years, save for better alloy parts, and injection and burn technology.

I've had trucks do 8 years service and 400,000km and still never use oil or show any obvious signs of deterioration

Older engines tend to be a bit more over engineered too, and arent built with the 'life/part/cycle' ideology that exists today .

[BogMonster]

No experience of small marine diesels but Dad has a Lister TS3 generator that did 30,000 hours before the heads were even taken off, still in perfect nick inside and overhauled ready for the next 30k!

Also on the farm we have a Lister 6/1 shearing engine (belt drive to an overhead shaft driving the shear motors) which was installed in 1958 and has never had anything other than an annual oil change in 52 years, though admittedly I've only known it for about the last 20. Doesn't even have a proper air or oil filter just chugs away at 600rpm forever. I don't know how many hours it has done but I'd guess somewhere north of 50,000 even though it sits unused for about eight months of the year every year.

Yes they both sit in a dry shed not around salt water, but if I had any diesel engine and only got 1500 hours out of it before it went bang, I think I'd be pretty p'd off.

The first set of Volvo TAMD61 marine diesels in the Nelson 42 at work were replaced at 12000 and 14000 hours.

[willk]

http://www.yachtsurvey.com/GasDiesel.htm

This article may be of interest to Wildwords, unfortunately it seems to support Mollers' theory about limited usage in leisure applications leading to shortened engine life.

I appreciate that it is at odds with the Boatsafe article.

Once again, I profess to have no knowledge of the matter , so nothing new there!

[Mollers]

Some farms around here have only ditched the Lister Startomatic gennies in recent years. A genny application is diesel heaven, light load, constant revs and a warm dry home. Just add fuel and occasional oil.