Inboard diesel hours life expectancy

[myusernam]

Assuming servicings have been done, how many hours before say 150hp vovlos are shagged? I.e. what is a reasonable service life - 3000 hours - 6000? Once old can you rebuild or is it more cost effective to just replace? Most boats this vintage seem to replace engines rather than rebuild..Is there a reason for that? (cost i guesss) Also Volvos are very expensive parts aren't they?

[Noelm]

I guess like all boat motors, it could go for twice that long, but salt water years are salt water years, rust/corrosion will probably kill it long before it wears out.

[Midnight]

Yep, what Noel said. Marine age and lack of use is what kills most of them.

Volvo parts are expensive, for sure, but they do make nice engines. Getting one that has been used regularly, not over propped, serviced as per the books or better is the key to a long and happy marriage with a marine diesel.

My V8 Cats have 26 years and over 5000hrs on them, and I fully expect another 5000 out of them yet.

If you can be a little more specific with the engine model and application, you will get a better answer.

Cheers,
Myles

[mal555]

I think most/any marine diesel parts will be expensive.

Every application will differ depending on how the engines have been maintained.

As Myles suggests, perhaps be more specific on the model/year?

Generally though many folks like new technology regarding anything they buy or repower, unless they have confidence in their own ability to keep the older engines running reliably.

[bluefin59]

I know a charter boat owner with twin yamnar turbo diesels and dropped one after it had done just on 1000 hrs and it would have cost a bomb to reco so ended up putting a new one in that cost 50K ,it suffered from salt water ingestion through the intake manifold and these motors where both checked by a marine mechanic and oil samples taken before boat purchase...Matt

[Midnight]

Bluefin, was it an after cooler failure that caused the saltwater ingestion, or poor installation? Yanmars are a good thing when set up and maintained right.
I have a mate with 5500+ hours on a 440hp Yanmar, and it is going like a beauty, with very little blowby or oil consumption.

Cheers,
Myles

[myusernam]

I know a charter boat owner with twin yamnar turbo diesels and dropped one after it had done just on 1000 hrs and it would have cost a bomb to reco so ended up putting a new one in that cost 50K ,it suffered from salt water ingestion through the intake manifold and these motors where both checked by a marine mechanic and oil samples taken before boat purchase...Matt

how the fark can one diesel cost that much. you could buy a truck, throw away the car part and put the diesel in there.! rediculous.

My old boy marinised a chinese diesel himself - he made a heat exchanger out of some plate and some copper coil. Fiberglassed an aqua lift muffler out of a bin! But you can just bolt on a heat exchanger and cool the exhaust. I dont get it...

[chris69]

Anything volvo is expensive,if its an older motor you should get good life if maintained,it depends apon how it was driven realy and what rev range its been operating at and weither there are any stress fractures and fatige in the head and weither the seals are ok in the linners, all the sevices in the world dont tell you weither the head is stuffed other than loss of water in the header tank if its got one,oil sampleing will only give you metal samples to determine what is wareing and at what rate the ware is happening over a time of doing S.O.S

Haveing a compression test would be the best thing to tell you were the motor is at and how much life is left diesels can run for many thousands of hours.

Gee matt 1000 hours is not much even for a yanmar something wrong there as Midnight said his CATS are old but there good old stock and have allways been a good thing other then the Kmart cats and he could get more than 10,000 hours,ive seen 20,000 to 26,000 hours on diesels in trawlers, trucks can go 1,000,000 miles before a rebuild but only because they dont cool down like taxies.

[mal555]

Yanmars are a good thing when set up and maintained right

I remember a number of years ago a major Queensland power cat manufacturer claiming they would never again install a Yanmar engine due to serious mechanical problems customers had
experienced within a few hundred hours of operation, quickly shifting the blame from what was clearly installation issues, back to the engine design.

I noticed in the latest Maritimo/Mustang blurb they are boasting (as a first in Oz) a complete Volvo factory endorsed installation check-off on each of their new vessels with IPS.
This company are trying to establish an export market into Europe where CE certification is standard on any vessel built or imported.

There could be something in this other local manufacturers could learn from?

[myusernam]

off topic but yanmars are toyotas aren't they? Why cant I just get a rebuilt or wrecked car turbo 6cyl out of a cruiser ute and bolt on a heat exchanger and gearbox. throw a few anodes in some welch plug holes. get the exhaust shop to make a mandrel bent stanless exhaust to suit the boat and have a belt run jabsco cooling the exhaust? What horsepower do they run at? Be around the 200hp?

[bluefin59]

Yeah way expensive but that was a brand new motor complete fitted from yamnar as a rebuild on the old motor was going to take weeks and parts had to be imported to do the job . But having said that the guy had only just bought the boat and it is his lively hood ,but now he is up to 3500 hrs on the old motor and 2500 on the new motor, the intake manifold was unbeknown to him sucking salt air which destroyed the turbo which dropped bots all through the engine, it was way ugly. And as far as cost goes I can't understand the price of outboards , look at the price of say a 140hp motor all upward of 16 k and a 300hp I guess would be over 35k , bloody rediculious ..Matt

[bluefin59]

Also it was a turbo diesel motor and the destroyed motor has now been rebuilt with overseas parts and put together by a catapiller mechanic . That's part of the problem that charter customers don't see it looks like a dream job but over the years I haven't met one that's wealthy from owning just a charter business , too many hidden costs and too much crap weather ...Matt

[chris69]

off topic but yanmars are toyotas aren't they? Why cant I just get a rebuilt or wrecked car turbo 6cyl out of a cruiser ute and bolt on a heat exchanger and gearbox. throw a few anodes in some welch plug holes. get the exhaust shop to make a mandrel bent stanless exhaust to suit the boat and have a belt run jabsco cooling the exhaust? What horsepower do they run at? Be around the 200hp?

Car diesels are not marine diesels different bore and stroke to achive the hp and toruqe at a lower revs.

[chris69]

Yeah way expensive but that was a brand new motor complete fitted from yamnar as a rebuild on the old motor was going to take weeks and parts had to be imported to do the job . But having said that the guy had only just bought the boat and it is his lively hood ,but now he is up to 3500 hrs on the old motor and 2500 on the new motor, the intake manifold was unbeknown to him sucking salt air which destroyed the turbo which dropped bots all through the engine, it was way ugly. And as far as cost goes I can't understand the price of outboards , look at the price of say a 140hp motor all upward of 16 k and a 300hp I guess would be over 35k , bloody rediculious ..Matt

Hi Matt did the yanmar have a intercooler on it!

[bluefin59]

Not sure Chris i could make a call and find out but it's not important now but maybe someone here that has a black watch with twin yamnar would be able to comment ? Are you going to be on the water by summer Chris ..Matt

[chris69]

Yer matt before that i hope fitting out the inside now and yes was just curious if it was because the intercooler can catch the stuff comeing of the turbo fins and block it up and reduces the performance runs rich and blows more black smoke and makes the exhaust side of the turbo glow red with unburnt fuel and thats a good sign of it,cheers chris

[Midnight]

No engine likes sucking salt water, high boost turbo diesels like it the least.

A lot of engine installations leave a lot to be desired. Often the install is done to suit the boat builder, or the installer, not what is best for the installation. The biggest killers are poor dorade system and salt water entering the engine room and inlet, followed by insufficient height in the exhaust riser above the loaded water line level. Any engine install using the factory exhaust elbow really needs to checked for the turbo exhaust height above the static loaded water line level. A lot of them are only inches above it, leading to the exhaust side sweating, and at worst, water even sloshing into the exhaust side of the turbo.
It is easy to spot. A well thought out install will use ALL of the available height in the engine room to get the "spill over" point well above the water line. 12" is considered a reasonable minimum.

A lot of the IPS installations worry me, as they have the engines under the cockpit sole, and there is bugger all opportunity to get the exhaust well above the water line at any point. Time will tell ow these work out.

Cheers,
Myles

[mal555]

A lot of the IPS installations worry me, as they have the engines under the cockpit sole, and there is bugger all opportunity to get the exhaust well above the water line at any point. Time will tell ow these work out.

Cheers,
Myles

Remembering the Aus market is probably 1/2 of one percent (being generous) of global sales of IPS, it's been interesting to gauge the responses of boaters from a big volume sales country like Britain during the last few years.
Finding technicians while cruising outside major population centres and paying for expensive repairs and parts seem to be constant negatives regarding the system.

[Bros]

Car diesels are not marine diesels different bore and stroke to achive the hp and toruqe at a lower revs.

I don't know what it is like now but Perkins certainly used the same engines in trucks as they did in marine engines

[chris69]

Yes they did Bros but then again a truck engine still dont rev as high as a turbo landcruiser motor as was mentioned there just a different configeration peak torque and hp is developed lower down in the rev range.

[BM]

5000 hrs would be a minimum lifespan in my view for the older breed of diesels.

I read an article a while back suggesting the new (at the time) marine diesel from Mercruiser was good apparently for around 500hrs before rebuild!! This is likely to be common with any small displacement high revving 'stressed' diesels.

The 8 ltr (270hp) diesel in my truck tops out at 2900rpm. A traditional sort of max rpm.

I would be surprised if any of the marine diesels are an engine built just for that application. Too low volume and therefore not enough money in it. Just like Mercruiser dropping their best engines the 470 series. Brilliant engine but why continue costly low volume production when an off the shelf mass produced engine is cheaper and easier to source?

Myles I'd be impressed if you get 10,000 hrs from your engines and I bet your piggy bank would be too!! The prices thrown around to repair marine diesels is obscene. I was looking at grabbing a 29 Searay flybridge walk around about a year back. Mercruiser (VM) diesels. One had died. Got onto a parts supplier in the UK and about 3K for all the bits for a full rebuild (not including turbo or injector pump) including freight.

Owner quoted 30K to rebuild. From my calcs about 6K (with a buffer in there) not putting a price on my own labour. Even if you did it for 10k it'd be a good earn or at 15K a great earn but 30K????

[Midnight]

BM,
My Cats are like your truck engine, only I'm extracting 260hp from 10.4L, and cruise at 2300rpm. I am running a duty cycle of around 18%, so they are not working hard.

A little different to a 315hp, 4.2L Yanmar, running 28psi of boost at 3800rpm, being used in a point and shoot pleasure boat. If this category engine, regardless of "colour", is not installed correctly, propped lightly and looked after well, they will never last.

Re the difference between the Landcruiser engine and the marine Yanmar. The Yanmar is producing over 100hp more than the Cruiser, and it is being asked to produce the maximum HP of the Cruiser engine, for most of its time running. They are different internally, and they are a highly strung bit of gear.

Don't get me wrong, I like Yanmars, but they need to be set up right and loved, just the same as any other 60hp+ per litre engine.

Cheers,
Myles

[BM]

Yep, sure sounds like your donks are doing it easy! Good to know.

So that would then suggest that lack of maintenance would likely be the only serious threat to their life which is in your control so that should work out well.

From a sales perspective, reluctance would come into play with engines having 5000 hrs on them. Been looking for a boat like yours for a mate/customer and 5000hr+ engines are putting him off unless he can factor in a rebuild shortly and price accordingly.

Cheers

[BM]

I've not heard of failure issues with that 315hp Yanmar but I agree with its low swept volume and high output and revs it's in the 'danger category'. Thats the super and turbo charged engine isnt it?

[Midnight]

BM,
Hi hours can certainly be off putting, but for me, it is more about how the hours were put on, the duty cycle and how they have been looked after. Also the type of engine and it's installation.

The other big consideration, is how the vessel is intended to be used after purchase, and the intended hours per year.

For example, an engine like a 6LW Gardner or natural 3208 Cat, with 5000hrs on it, well looked after and in good general condition, in a trawler type hull pleasure boat, will most likely out live the new owner. Low HP from big iron and a low duty cycle equals long life.

On the other hand, a planing hull sports fisher or "Searay" type cruiser, with 60-70hp/L turbo diesels, that were propped on the edge by the manufacturer and run at 80%+ load everywhere they went, with 5000hrs on would be some cause for concern and budget for a rebuild or repower, would not be so silly.

The 315hp 6LP Yanmar, the 4.2L Landcruiser derivative, is an excellent engine with very few in service failures that have not been from poor installation or lack of maintenance. Definitely a good engine. It just features in a few blow ups, because it is a popular choice, and tends to get put into applications where it will get run hard.

It is in the same category as the QSB series 5.9L Cummins. It started life as a 210hp engine, that now makes right up to 480hp, over 81hp/L. If everything is not A1 in the install, operation and maintenance here, things go bad very quickly.

The public demands efficient, light, high output engines these days, but it will be rare to see many of them last the distance of the old iron....

I think you really have to take each engine install and hull combo on an individual basis.

Cheers,
Myles

[BM]

I agree with you more or less entirely. Can't add to it really other than to say beware the high revving, new breed, light weight diesels!

[Midnight]

beware the high revving, new breed, light weight diesels!

Or I could have just said that instead of writing a saga haha sorry it was late and I got a run on the keyboard haha

[BM]

Nothing wrong with a big of obtuse explanatatory action mate! Quite partial to that myself lol ;D

[Stuart]

I think you will find that most diesel engine problems arise due to poor maintenance and crap fuel. I understand there is a hue difference between road-designed diesel engines to that of marine. For a truck or even small diesel engines, you should see well over 1 million kilometers. I spent my share of time on trawlers, both big and small and the number one killer for those engines was crap fuel. One of the smaller trawlers I worked on had blowers fitted to increase power. Those engines where rebuilt after 12000 hours, not bad when considering the load they are under for 10 hours per day. We did have plenty of filters and two diesel debug systems installed which helped enormously. You should get your oil analyzed every 6-12 months for any abnormal wear. I would also be running a diesel fuel treatment called DT5 from Pro-ma. We ran that in all the trawlers and we never once blew an injector tip or had the dreaded bug in the fuel tanks.

[Humdinger]

hey fellas i just got onto this . i have a boden design plate alloy 7.2 metre planing hull . am looking at chucking the outboard away and putting a 3208 natural with a leg on it . any views on this midnight

[Midnight]

G'day Humdinger,
What size outboard do you currently have, and what sort of speeds do you get?
What do you hope to gain by going to a diesel stern drive set up, over the outboard?

A 3208 natural will weigh close to 800kg and make 210hp at 2800rpm. I am not sure what make of stern drive you could use, and how you would mate it to the Cat.

Much better options out there for sure.

Cheers,
Myles

[Humdinger]

hi myles
currently have a 225 evinrude 2 stroke on it get about 55 kph , very thirsty engine
hoping it will be cheaper to run as a diesal . i have the 3208 already sitting here . was thinking of running a bravo 2 leg .
just a thought at the moment . would be cheaper than 32k for new 4 stroke

cheers brett

[Midnight]

No worries Brett,
I think the shear weight of the Cat will probably make it unviable really. You would really have to mid mount the engine and run a jack shaft to sterndrive, as the 900 odd kg's Caterpillar and Bravo 2 sterndrive mounted in the rear of your boat would most likely upset the trim of the thing something awful.
The Bravo 2 may handle the HP no worries, but you would have to check it for torque capability. Propping it would be the next drama.

Can you sell the Cat to help finance another diesel option? A 210-225hp Cummims 6BT and Bravo 2 would be nice. Great reliable engine with a long history, rebuild kits are cheap, no aftercooler to worry about.
Or maybe a 200hp 41 Series Volvo and 290 Duoprop sterndrive.

The 3208 Natural is really better suited to a displacement hull set up, where the weight of the Cat isn't going to really disadvantage the hull.

Cheers,
Myles

[BM]

Couldn't agree more. The 3208 and Bravo drive all hanging in the back of that boat, strewth, you would need to install a viewing panel in the hull bottom amidships so you could see forward to drive!!

Big jack shaft would be only plausible solution but even then the weight may simply make the boat wallow, sit too low in the water and be a general pig.

I'd be concerned with any diesel sterndrive being potentially unsuited to that hull other than the new breed of high revving, highly stressed, short life units we have been speaking of.

I'd reckon a chat with a naval architect would be money well spent before turning a spanner.

[Humdinger]

thanks fellas i think i will do some more homework . maybe better off selling the outboard and cat to help finance a new 4 stroke . i know i can hang 600 kg off the back but the extra 300 might stuff it .
i only went for the cat idea cause i have always been around them

[Midnight]

Yep, and fair thinking too Brett. They are a good beast, but just not really the best option for your hull.

Keep an eye out for some auctions to find a new outboard maybe, or look at bringing one in from the USA.

If you really want to go down the diesel route, and keep it to the style of engine you are used to, then maybe look for a 6BT Cummins. They are a simple mechanical engine and very robust. Their only real weakness is the original Sherwood raw water pump, but there is an excellent aftermarket pump for them now. A Bravo 2 should work with that, however I'm not familiar with the Mercruiser drives to the extent of how it mates to a 6BT Cummins.

A 4LH 230hp Yanmar would be even better weight wise. These are a magic little engine.

Choices choices haha

Overall though, the most sensible choice of all, would probably be, sell the Cat and the current outboard, dog, wife, child etc and buy a 200 Suzuki 4 stroke.

Cheers,
Myles

[dugggy]

To get the Cat in there you would be looking at a similar set up to this I would expect8175981760

Cummins V504 around 900kg with a shaft to a 290DP

Doug

[Humdinger]

thanks . i think i will go the 4 stroke way . will be a lot less work .
now to sell the wife

[Midnight]

That's a wild set up Dougy,
What boats that in? Some thinking went into that one. Did it work well?
Cheers,
Myles

[dugggy]

Its in an F233 frankenboat Ive taken on as a project.Ex government I am led to believe by the P.O. Must admit cant see anyone else spending that much money on an engine install in a trailer boat.I havent had it in the water yet as I am still trying to get time to bring it down from FNQLD.
Doug

[Midnight]

Ah ok cool. A mate's son bought a 233 a while back that had a 454 petrol in it with a jack shaft to a big TR leg. I reckoned it was a good candidate for a diesel repowered and keep the mid mount config, but they were stripping it and going to pod it and put a big four stroke on the back.

Got any more piccies of your project Doug?
Any idea of performance?

Cheers,
Myles

[Jarrah Jack]

thanks . i think i will go the 4 stroke way . will be a lot less work .
now to sell the wife

Ebay auction, no reserve..................:)