pvb
Well-Known Member
Maybe not necessary, but a reassuringly good synthetic oil will only cost a typical owner about a tenner extra a year. Sounds like good value to me.
Diesel Engine Design Life
- Thread starter Norman_E
- Start date
Maybe not necessary, but a reassuringly good synthetic oil will only cost a typical owner about a tenner extra a year. Sounds like good value to me.
Fmicol
Active Member
Wich would be the life time of modern comonrail diesel engine compared to old traditional engines ?
lw395
Well-Known Member
Much the same I reckon.
I think most wear in yacht engines is because they only get used at weekends, giving them a whole week for all the oil to drain down between use.
While the egyptian taxi engine probably never had that problem!
CAPTAIN FANTASTIC
Well-Known Member
A "modern" engine will last much longer by design; better melalgurgy, more accurate machining, balancing etc, but at the same time they operate at higher revs increasing the wear, even so, "modern" diesels are more durable.
lw395
Well-Known Member
You still see the odd modern car with a pall of smoke behind it, and wonder has it done a trillion miles, has it been abused, or is it just chance that things fail?
Tranona
Well-Known Member
But what are you getting for the extra £10 a year? Is it better just because it is more expensive?
crewman
Well-Known Member
Common rail engines usually have complex electronic controls and it is these parts which fail and are expensive to replace or the parts become unavailable.
geem
Well-Known Member
Perkins quote 10000 hrs before the engine needs any work for their current engines. Oil changes are every 500 hours so I expect oil quality is important. We stick to the oil spec they demand as once a year oil change is not worth the difference between recommended oil and something cheaper
Daydream believer
Well-Known Member
Why? When were you thinking of going?
pvb
Well-Known Member
Better cold engine protection, better hot engine protection, better additives.
Momac
Well-Known Member
I have been advised good old mineral oil is best on older technology engines, so synthetic oil is not necessarily better. Use oil of a grade and type recommended by the engine manufacturer .
MM5AHO
Well-Known Member
We have a forklift at work with >30,000 hours - original engine. Naturally aspirated diesel with hydraulic drive. It has had a new head (cracked old one at about 19000 hrs), but all else original. Its still going. Look after a diesel and it will last a long time.
I have a 1965 Lister generator 19kVA, still going well, not burning oil, unknown hours.
I have a 1965 Lister generator 19kVA, still going well, not burning oil, unknown hours.
aluijten
Well-Known Member
The engine itself is not much different, mostly a different designed cylinder head (direct injection).
The scary thing is the injectors that are super sensitive to bad diesel, more specifically water contents in the diesel. Because of the high pressures used in the system any water will cause the injector nozzles to erode to bits. In case of common rail system these injectors are really expensive. Added to that is the extensive electronics suite required to make it all work.
So for your basic sail boat engine this is something to avoid, despite the lower fuel consumption.
Fmicol
Active Member
Did some people have experience in many hours for diesel with commonrail and turbo,recent engines from 2000?
contessaman
Well-Known Member
Suspect thats Turbo wear. Smoke from over fuelling due to worn turbo- not the engine itself.
My mercedes smokes if you hoof it and the poor old turbo whisltes away but the car has done 250K and it doesnt use a drop of oil.
The only diesel car I have had that never smoked was a non turbo ford escort van. 300,000 on that sucker. a puff of smoke on start up but after that nothing.
BrianH
Well-Known Member
Four years ago I posted on here a query about if I should replace my 30-year-old VP MD17C that had a few minor problems, but I foresaw others looming. The general consensus was that I should, which I ignored and had the engine repaired by a star mechanic with a workshop filled with old replaced VP engines that could be cannibalised and renovated, in the light of no-longer-available spare parts. He himself also advised a new Nanni N4.38 - but then he would, being a Nanni agent. But he's a good guy who cheerfully got on with patching up the old engine whenever asked.
Then last week on returning to the marina for laying-up the temperature gauge was exceeding even its normal excursion into the red limit and steam was issuing from the exhaust along with the normal stream of water. I knew the raw water cooling had been impeded for years with a sludge of calcium and rust in the engine cooling channels but it now seemed to have reached a crisis point; time to visit my mechanic again.
I found him and his partner on the final stages of renovating a used Nanni N4.38 for display at the forthcoming local Nautic exhibition. Over the next two days I found myself agreeing to buy, and to have fitted over the winter, the Nanni engine - luckily the CFO had arrived to help me lay-up and so she could participate in the negotiations and approve the expenditure - and being fluently Italian-speaking could confirm just what was being proposed between us in German and my pidgin Italian.
So I'm sure the old engine could have been bodged-up yet again and it would have soldiered on for many years, but at a cost that I prefer to invest in a newer engine with closed freshwater cooling, for - as you point out - raw, salt-water cooling can be the killer of an older engine. Of course it helped to have the chance to buy a used one at half the cost of new - with guarantee, of course.
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RichardS
N/A
I know this is covering old ground but the single biggest advantage resulting from the above is extended oil life. When Mobil 1 was first launched it was horrendously expensive .... probably equivalent to something like £100 for 5 litres at today's rates. However, it was sold with a technical document which explained that you could extend your oil change intervals up to 3 or 4 times the vehicle manufacturer's recommendation. Of course, as the relative price has dropped then so has that fact been dropped.
I started using Mobil 1 as soon as it was released but because I was using it in a high-performance bike I think I only extended to 2x recommendation. Filter changes have to be at the normal interval.
The longest I have gone is with my V8 car is 5 years between changes. I stripped the top end down a couple of months ago and it looks like new - no wear, no staining. It has only ever been run on Mobil 1.
For viscosity reasons I'm running the boat engines on semi-synthetic but that oil is easily lasting 3 seasons. I might switch to fully synthetic next time although I'll have to buy it online and I reckon 5 year changes will be possible. However, when it needs changing, it needs changing!
Richard
Tranona
Well-Known Member
Why do you think you need that and why it is not provided by the oil recommended by Volvo is minimum API CG. Cold weather down to -15 for 15W/40. Given our conditions here, difficult to see what value there is in using a higher specification oil, although Volvo do say it can be used if the lower spec is not available. If it was essential, or even "better" - surely they would recommend only using synthetic or semi synthetic?
Tranona
Well-Known Member
For viscosity reasons I'm running the boat engines on semi-synthetic but that oil is easily lasting 3 seasons. I might switch to fully synthetic next time although I'll have to buy it online and I reckon 5 year changes will be possible. However, when it needs changing, it needs changing!
Richard
Extended life is irrelevant in boat engines where the recommended change points are usually 150-200 hours, or typically a season. Conventional oil has no problems with that sort of interval.
Trying to transfer experience for road vehicles is misleading. Boat engines have a specific power output of usually around 30hp/l compared with modern road vehicle engines which are minimum twice that and common now tombe over 100hp/l. A boat engine generates far less heat than a road engine, runs most of its life at 70% maximum - 2200rpm and 20hp for my D1-30 for example. Where is the requirement for lubrication anything like as demanding as that on my 2L turbo diesel Ford (which does require synthetic oil - and gets changed every 300 hours or so) and uses the full revs and power range almost every time I drive it?
lw395
Well-Known Member
I disagree.
On a used low tech boat engine, I think the oil is still just as prone to contamination from water, fuel and combustion by-products, so I think it needs changing roughly as often. Maybe a bit different if the engine has always been run on synth so hasn't worn, and the oil isn't getting dirty.
I would say the main advantages are film strength, resistance to draining off the metal surfaces and wear resistance.
Just trying to clean good synth oil off your tools shows it's simply better at keeping metal oily!