Engine hours - why important?

[DSWright1]

I would be grateful if someone could explain why lower engine hours are important. I am considering buying a boat with 1000 hours (whereas there are same models on the market with 300-400 hours for another £10k). I would like to know what risks I am taking - is the high engine hours bad because it is indicative of the wear on the boat generally, or is it that the risk is to do with the engines themselves? I had always been taught that diesel engines "run and run".

 

[fireball]

but have they been run in idle or on power? ...

 

[DSWright1]

Let's presume on power

 

[T43]

Engine hours ??? All depends on which engines your prospective purchase has in it. Normally asperated turbo deisels properly maintained usually run & run, whereas supercharged higher revving more highly stressed KAD's are more prone to problems.

With regards to the boat one that has more hours on it has in most cases been used more and better cared for than one that has sit around doing nothing.

Hope this is of some help. /forums/images/graemlins/smirk.gif

 

[jhr]

Lower hours aren't necessarily a guarantee of better reliability and many would argue that regular usage is much better for the engines than sitting unused for weeks on end, mouldering away. Much more critical is how well they have been looked after - are there copies of regular servicing invoices, have the manufacturer's recommendations been followed vis a vis replacement schedules and does an oil analysis throw up any nasties?

As you say, diesels run and run, and 1,000 hours is really no time at all. Badly maintained and irregularly-used engines with 400 hours, however, could be at death's door.

 

[gjgm]

I'd add that lower hours is thought better.. coz everyone seems to think so, so, sort of self fullfilling, and even if 1000 hours is fine, there will be some premium for lower hours.
Still, higher hours means someone really did use the boat, and people who are out at sea alot probably dont tend to think cutting corners on the engines is a wise move. If you only do 20 hours a year, maybe you dont feel so keen to pay those vast bills for more or less unused components.
Biggest issue though is that people are nervous of higher hours, re selling, albeit perhaps out of ignorance.

 

[[2068]]

Low or high hours just means different things to check.

E.g. low hours: check that the turbo still produces full boost, no corrosion issues, all servicing still done, belts happy and pulleys not rusty, clean filters etc.

High hours, check for leaky gaskets, leaky water pumps, condition of exhaust pipe, pulley tensioners not squeaky etc.

Not sure which I'd rather have, other than a new boat with zero hours, and that high hours is also a cue to check condition of interior (general wear and tear).

dv.

 

[Nick_Pam]

I'm with JHR on this and applying the same philosophy in my search...
Hours are no issue within reason - it's the lack of service & maintenance invoices that would worry me.

 

[Hurricane]

I believe that with most engines that 1000 hours is a bit of a milestone - dont the injectors etc need servicing at 1000 hrs? - Also, I think valves need adjustment etc.
Maybe Col will post on this one.
It would be good if a full 1000 hrs service had already been done - otherwise ask for more discount as (if I'm right) there is particulally a lot of servicing at this particular age.

 

[Who]

Look at it this way

A car does say an average 40mph and runs for 1000 hours.

That makes 40,000 miles. That makes it low mileage.

As long as the engines are serviced i dont think there is an issue. Apart from the boat condition of course.

 

[Nick_Pam]

A good point...I've worked on the principle that high engine hours are likely to point towards cosmetic expenditure (cockpit cushions; teak decking replacement etc) due to the level of use...not necessarily towards major engine works - pilot boats in the channel run for 20-30,000 hours before major overhaul, apparently.

 

[oldgit]

Its the condition of the entire boat that counts,with a decent number of hours on the meter,stuff will have already broke and been fixed,with low hours they are just waiting to break....at your expence.

 

[Deleted User YDKXO]

First, the probability is that a 1000hr engine is nearer the end of it's life ie a major rebuild than a 400hr one but it also depends on what type of engine it is. A naturally aspirated, low revving lugger of an engine as you might find in a commercial boat or a displacement motor boat, should last for many '000's of hours. On the other hand a planing or semi displacement boat may be fitted with high revving, turbo and supercharged engines developing a very high power for their capacity. These engines will probably have a much shorter life
Apart from the engines, a high hours boat will have likely had far higher use of it's other systems like domestic equipment, heating/aircon, generator, plumbing and water systems and all are likely to need maintenance sooner on a high hours boat. Then the woodwork and soft furnishings are likely to need renewal and this can be very expensive
The biggest reason for buying a low hours boat is that the used market perceives them to be more attractive so, IMHO, a high hours boat needs to be at a substantial discount to be worth buying
The ideal boat has about 50-100hrs/year use, if it has been used as a sea boat, maybe double that if it has been used on inland waterways.

 

[Greg2]

The issue of low hours on boat engines is one that is exploited by sellers and brokers because people naturaly think that like a car low engine use/miles is good. In reality it is absolute tosh IMHO.

Diesel engines are best used instead of sitting idle and quietly corroding and the number of hours on the average pleasure boat is not going to be anywhere near needing a rebuild or anything like.

The link between hours on an engine and use of a boat is also questionable as many people spend a lot of time onboard but don't go anywhere. The key issue is overall condition of the boat and engines. A service history is good but in it's absence an engineers report that includes oil sample analysis can provide a lot of reassurance.

I have long held this view and it was supported recently in the 'Secret Salesman' column in MBM.

I'll stand back now and await the barrage of criticism... /forums/images/graemlins/wink.gif

 

[fisherman]

Don't know about the sort of engine you are looking at: I have a Ford Mermaid 'Dover', much the same as the later Otosan or earlier 'Dorset'. Naturally aspirated 6 litre 6 cylinder, basically a lorry engine. Current engine is on 7000 hours, and has only had oil & fuel filter changes, (every 200 hours) and belts (every year/1000 hours) apart from replacement of an oil cooler. Last engine did 14000 hours, but it didn't wear out, it developed a crack next to a core plug, so the plug dropped out. It was using 1 litre of oil per 100 hours, same as this one. The engine was stripped by the insurers and declared unworn, ie I got a full replacement.
Mermaid say when the oil consumption is 2% of fuel consumption the engine is worn out.
As others say, it's more about maintenance and treatment. A turbo-charged engine does not like going straight from flat out to idle. Opening up while the engine is still cool is not good either. Persistent treatment like that is likely to have aged an engine beyond its hours.
All IMHO of course

 

[rosssavage]

Maintenance maintenance maintenance.. Diesels (especially turbo..) live on clean oil. My donkeys are 20 yrs old with 2300 logged hours, much of that sea time (say 75% power for long periods at a time) and they are in top nick. Had oil analysis done pre purchase (again a must IMHO) and a good poke around - there is the obligatory surface corrosion and paint flaking for old engines, but internally no issues. I think the overall condition of the boat speaks volumes and offers the best insight into potential future problems. My boat is comparitively old with high hours, but upon purchase all the filters / comsumables installed were pukka volvo bits and she had had a recent full interior refurbishment - the previous owners had obviously cherished her, and this instilled some confidence in me that there were no major undetected problems. Using the boat a lot keeps condesation at bay in the engines and alerts the owner quickly to any unusual behaviour due familiarity with the feel and noises of the boat. If the boat is used 20 hrs a year the owner probably cant remember what their engines are supposed to sound like, never mind if they sound wrong. Bear in mind that most marine engines are derivatives of road engines - mine (TAMD 61a) are based on those fitted to older volvo trucks, and are designed to be run near enough flat out for 8 hours a day and can rack up starship mileages. A few thousand hours is nothing to the big expensive bits as long as maintenace schedule is observed and care is taken warming up and cooling off every time theyre used.

 

[oldharry]

1000 hours is less than half the reasonable life expectancy of an engine before needing serious attention. 2000 hours you can wonder if the injectors may need re-setting, 3000 the head and valves may need attention

IF IF IF it has been properly maintained and has been run hard regualrly. And above all has had oil changed regularly on time.

If not, its knackered and you can expect big bills.

 

[Piers]

As commented above, it all depends on Maintenance, and whether the engine has been used in accordance with the manufacturer's guide lines.

Maintenance history is hard to prove since we all know that what is actually done during service is not always what is stated as having been done. Missing service items can be the start of very real future problems. This applies whatever the hours done, especially where winterising applies. However, Oil Analysis can help enormously in this area (more info in a paragraph ot two).

Usage? Some diesels are OK to run at low rpm for long periods given certain provisos, like my Cummins 450Cs. It all depends on what the manufacturer says.

So, can you believe what the service history says (even if carried out by 'professionals')? Has the engine been used as the manufacturer says? If yes to both qns, hours used fades as one of the last concerns when choosing to buy or not.

However, oil analysis can help answer both these questions. Oil analysis companies require such info as engine type and model, hours run, make and grade of oil, hours run since last oil change, etc, etc.

Analysis can show abnormalities such as excessve bearing wear, failed or clogged air filters, fuel injection system malfunctions, fuel dilution, incorrect oil grade, glycol/coolant contamination, leaking heat exchangers, failed head gaskets, etc, etc. It can also show if the engines have been run for long periods not in accordance with the manufacturers recommendations and are therefore starting to suffer from bore glazing or varnish effects. (info courtesy of Passage Maker magazine dec 2007).

I started having the oil analysed on Play d'eau some years ago since this says more about the engines than almost anything else to a future buyer.

 

[Deleted User YDKXO]

I've bought and sold a number of boats and, on a couple of occasions, considered buying high hours ie 1000hrs+ boats and, on both occasions, the oil analysis has saved me from an expensive mistake by alerting me to excessive contamination and impending big bills.
Obviously, estimating the wear life of an engine until a major rebuild is required is a complex subject but it is an accepted fact that operating hours and no of cold starts are major factors. Obviously, a high hours engine, apart from it's higher hours, is also likely to have a greater no of cold starts. Yes, regular maintenance and careful use can greatly extend engine life but it just is'nt logical to claim that on average a boat with low engine hours has'nt got more life left in the engines than a boat with high hours
With regard to overall condition, my own experience of high hours boats is that the interior tends to show those hours. Yes some boats are used as weekend cottages but in the main, high hours means high wear
But all this is academic because what really counts is market perception and the market generally percieves that high hours boats are worth less than low hours boats

 

[Bajansailor]

Commercial fishing boats here generally clock up around 1,000 - 1,500 hours per year on their boats. And these are all single engines, not twin.
Their owners invariably look after them well, and change the oil and filters every 200 hours. They are not the super-duper hi-tech high revving Volvos - rather they are usually Perkins, Ford (Mermaid or Sabre), Cummins, Caterpillar, and John Deere, all usually turbo charged.
And they keep going a long time - 10,000 hours on these engines happens regularly.
Another adage is diesels used for generators - I recently saw a Cummins generator set that was a bit over 3 years old, with 22,000 hours on it, and working well.....