How many Engine Hours is Too many?

[aclmck]

I have been looking around at used Catamarans with 30 -57Hp SailDrive engines both Volvo and Yanmar (mainly) most of the used cats have 2000- 5000 hours on them, now i assume a large part of these hours are for battery top ups, but i was not sure how long these small engines were designed to last can anyone tell me what is an average life for these motors.

[Hudson Force]

It's difficult to evaluate an engine by the hours run. It might be better to evaluate them by their maintenance history,- oil changes, valve adjustments, filters, etc. A well maintained diesel engine can easily reach 10,000+ hours.

Frequent operation of an engine is often a better indication of good condition. I would be more suspicious of an engine with 2,000 hours and long periods without use than an engine with 6,000 hours with frequent runs up to normal operating temperatures.

[aclmck]

Originally Posted by Hudson Force

It's difficult to evaluate an engine by the hours run. It might be better to evaluate them by their maintenance history,- oil changes, valve adjustments, filters, etc. A well maintained diesel engine can easily reach 10,000+ hours.

Frequent operation of an engine is often a better indication of good condition. I would be more suspicious of an engine with 2,000 hours and long periods without use than an engine with 6,000 hours with frequent runs up to normal operating temperatures.

Hi, these boats are all in a charter company and from what they say are all serviced correctly (that' would be anyone guess finding out what it actually means ) but generally these boats are welcomed by many and i hear of little problems with them after purchase, so i would assume a reasonable care of service would normally have been completed, that being the case these motors should easily (with regular servicing) be ok for upwards of 10,000 hours is that what you see as possible.

I spoke to one chap who serviced a boat in a marina and asked him, he said they get regular servicing as most have this in their contract and the actual owners get a copy of the service document to know that their investment is being looked after, he also said that they didn't like any breakdowns at all as the hire company didn't like having to refund cranky customers,mostly the motors were serviced well he said but some of the legs were not serviced to his liking. (whatever that meant) he also said that the engines were on average used about 60% to charge battery banks, not sure about that but possible i expect with no other form of energy.His thoughts were that generally they get better serviced than the privately used boats on average.

[Kenomac]

Charter boats that I observe every day are run much harder than privately owed boats and spend more time with the engine idling to charge the batteries, which can be even more harmful especially to the turbo charger.

After watching this in person, I would never have any interest in ownng a previous charter boat. They get clobbered, all systems including the sails and rigging..... absolutely clobbered.

[a64pilot]

Buying any used boat, or in fact I guess a new one too, is sort of a crap shoot. To maximize your odds of success, you educate yourself as much as possible, and hire experts to survey those parts that you worry about.
My little Yanmar for example had accumulated 500 hours, in 27 yrs, I was prepared to have to overhaul it based on likely bore glazing from so much dis use, but I've put about another 500 hours on it in three years and it seems fine.
I would hire an expert engine surveyor if I were you, but based only on what I read here, it may be the drives you need to be more concerned about than the engines?


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[barnakiel]

If hours is your only indicator, sure fewer be better.

Modern light diesels are not old heavy diesels. 10000+ hours is wishful thinking.

Look at the specific engine you want to buy: you can get oil analysis, you can get compression test. Feel how it starts cold, look at the smoke, etc. Signs.

IMHO 2k is generally OK. I would buy a clean and well starting 2k modern diesel.

b.

[nauticalnomad]

Originally Posted by Kenomac

Charter boats that I observe every day are run much harder than privately owed boats and spend more time with the engine idling to charge the batteries, which can be even more harmful especially to the turbo charger.

After watching this in person, I would never have any interest in ownng a previous charter boat. They get clobbered, all systems including the sails and rigging..... absolutely clobbered.

Id buy an ex charter boat if it was cheap enough.
And i could replace everything when i needed to.

[Capt Phil]

Originally Posted by aclmck

I have been looking around at used Catamarans with 30 -57Hp SailDrive engines both Volvo and Yanmar (mainly) most of the used cats have 2000- 5000 hours on them, now i assume a large part of these hours are for battery top ups, but i was not sure how long these small engines were designed to last can anyone tell me what is an average life for these motors.

Buying a boat is like acquiring a wife/partner. Regardless of how many hours she might have on her, it will depend on how she was treated, maintained and cared for. Look for signs of abuse, neglect and poor maintenance.
If you find one that looks, sounds and appears in good shape, look deeper into what she might have been through, ask around about how she was cared for and the time the previous owner spent on her. She might reveal some secrets about herself that will either seal the deal or send you running! Good luck... Phil

[daletournier]

Originally Posted by barnakiel

If hours is your only indicator, sure fewer be better.

Modern light diesels are not old heavy diesels. 10000+ hours is wishful thinking.

Look at the specific engine you want to buy: you can get oil analysis, you can get compression test. Feel how it starts cold, look at the smoke, etc. Signs.

IMHO 2k is generally OK. I would buy a clean and well starting 2k modern diesel.

b.

I disagree. Ive said this before on Cf, I see yanmars with 5000+ hours regularly. I make a point of asking owners what hours they have on their engines. I said this before also but its worth repeating, I know a guy with 14,500 hrs on his 50hp yanmar, hes putting a new motor in at the moment, not because anything is wrong with his old one, its just he heads remote each year and just wants to be sure.
We talk about old engines being better, but I disagree. When I was a young apprentice motor mechanic one of the things we would do is strip our engines down and get them blueprinted and balanced, ( performance) better tolerances etc. I believe todays engines are machined using better and more precise manufacturing equipment and processes thus leaving the factory better than the engines of yester year. Think of the miles you now get out of toyota car engine compared to a 1980's holden ( or chevy).
I expect 10,000 hrs out of my 3gm30f.
2,500hrs on a fulltime cruising boat isnt very much.

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[seabreez]

Originally Posted by aclmck

I have been looking around at used Catamarans with 30 -57Hp SailDrive engines both Volvo and Yanmar (mainly) most of the used cats have 2000- 5000 hours on them, now i assume a large part of these hours are for battery top ups, but i was not sure how long these small engines were designed to last can anyone tell me what is an average life for these motors.

To do an equation or to compare with something you and I can relate to, at one time there was a norm that would compare 35,000 car mile to 1000 boat miles. Now the engines are so much better that the new norm is to compare 1000 boat hours to 30,000 miles. When you think about the hours done so far and what you are good for, it gives you an idea of how far you can go. Go for it! Drive it...

[nortonscove]

We've had 50hp generators on the tug we'd just sold with 27000 and 19000 hours. Transport Canada requires them to be taken down for inspection at regular intervals and the most recent inspection saw no defeciencies once more. They are both Perkins models that run for days at a time under normal use.

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[kas_1611]

Volvo Penta engines are based on a Perkins block and there are tales of Perkins diesels doing the Moon and back with no problems.

Presumably if you are looking at the 30-57hp range we are talking basic VP engines with no fancy Common Rail injection or Turbos. We have the D2-40 so this would be slap in the middle of the range. Honestly you can't ask for a simpler engine - Suck, Squeeze, Bang, Blow - that is all it does and will do it happily at 1800rpm for hours. In 5 years we have put over 500hrs on the engine and every year it gets a full oil change, filter change (all 3 of them) and last year got the full 7 year service, yes I know 2 years early but as the engine had to be lifted anyway we got the sail drive seals changed.

To put it into perspective routine service intervals for modern auto engines are now as high as 30,000 miles, I have a 7 year 100,000 mile warranty on my car. I remember 20 years ago when a 10,000 mile service interval was impressive. I know of many petrol and diesel engined cars that have over 100,000 miles on the clock and still going strong, even heard of 250,000 plus miles (at a steady 60mph cruising speed that is 4167hrs!).

Hours on an engine is not the best indicator as an engine with high hours but only used to charge batteries, therefore not under any real demand, will not have the same wear as one that has been running at 1800rpm for hours and hours pushing a boat through the water. In the same way a 10year old engine with only a few hundred hours may give you more problems as it hasn't been used. Better to look at the servicing history and if you are really unsure about the engine get it professionally performance tested. And new engines can fail just as easily as an old engine.

That's my 2p worth

Keiron

[Capn Jimbo]

One of the problems with even or maybe especially with otherwise well-intended forums such as this is not getting enough opinions, but perhaps too many.

Thus, I won't add my own, but having faced this very question, I defer to the well-respected sailor and author Don Casey ("This Old Boat", etc.) and I quote:

"A well-maintained diesel engine should deliver 5,000 or more hours between overhauls... (but) that 5,000-hour number does not apply to engines with salt water rather than corrosion-inhibiting coolant running through them.

You will do yourself a real service by assuming that any engine has been neglected and abused until a thorough mechanical survey determines otherwise.

If parts are even available for a small diesel built 25 years ago, they will be shockingly expensive. Add to that the substantial labor cost of a rebuild and you are approaching or exceeding the cost of a new engine. Then remember that most of that engine is still 25 years old, and the workmanship of the rebuild is of unpredicatable quality.

In most cases a new engine will turn out to be cheaper, and will deliver a better result. And bolting in a complete engine is easily within the capabilities of most determined boatowners."

Carry on...

[Cheechako]

If offered two engines with 4000 hours on them, both being the same design, one only 3 years old and one 20 years old.... I would take the 3 year old one. It seems to me low use is the worst thing for marine engines.
Buying a cat with saildrives and engines with 5k hours I think you are likely going to end up doing a lot of work while you own the boat though. and a pleasure boat with 5k engine hours has likely been in charter.

[reed1v]

Our old perkins had about 16,000 hours on it when we bought the tub and we put over 35,000 hours over 30 years on it subsequently. When we sold the boat, the engine was good as new. Never rebuilt, only had the injectors serviced several times. Three in line fuel filters, two oil filters, one in-tank polishing system for both tanks(fuel was polished all the time), and regular changing of air filters. Treated right, a good diesel will last 60,000 to 100,000 hours. Anything less than 10,000 hours is barely broken in.

So if its a quality manufacturer of diesels , hours are not important. If you are buying a cheap, light weight model from some minor manufacturer, then you might experience a different reality.