Why do people replace diesel engines in a sailboat?

[Kokanee]

My 35 year old raw water cooled Volvo MD-17 was smoky, over-heated easily and was tough to find the expensive parts it often required. I was quoted $3500 and a 4 week wait for a just a starter motor from Volvo. I was never felt overly confident that she would get me home again each time we went for a cruise.
When I checked the dipstick one morning and found it covered with a white frothy mixture, it was a quick decision togo ahead with an engine replacement.

A new Vetus engine (with gearbox) was higher horsepower and torque, lighter, smaller, cleaner and quieter. All for the cost of 3 Volvo starter motors.
And yes - I did get a lot of joy in doing the engine replacement. But I kind of miss the old Volvo sound. dook dook dook dook dook

[Exile]

Originally Posted by Chotu

gallatin1988-

This is not backed up by any evidence or science. This is a personal belief of mine.

I have inherited plenty of old and barely used diesel engines in my time. In my opinion, as you start to put them into regular use, they kind of come back to life. I feel like the breakdowns are going to happen in the first few hundred hours after sitting a long time. Then after that, they kind of get into a groove.

OK Internet, please yell at me now. LOL

Not the first time I've heard this, and makes some sense. My old diesel generator always suffered from low compression, mostly from low usage and age, not hours. When it finally refused to start, I removed the head and sent it out for refurbishing. This seemed to cure most but not all of the symptoms, and I was told there was a good chance that, with additional run-in time, the rings have a good chance of re-seating themselves and thereby reducing a small amount of oil consumption that persists.

[newhaul]

Originally Posted by gallatin1988

For those of you in the know,

How does lack of use or extremely infrequent use factor in to engine reliability?

The boat I'm looking at has the original (circa 1978) Picses (Izuzu) engine in it. Maintenance records are spotty at best. It has seen almost zero use in the last couple of years.

The boat has has also spent perhaps at least 2 years (my guess after talking to the current owner who doesn't know) or maybe more on the hard in the last decade.

To my eye, it looks pretty rusty but it could just be cosmetic.

About a month ago a mechanic was able to it running (at least for 20 to 30 minutes) with very little trouble (oil change, filters, etc). If this means anything at all I don't have the experience to judge.

In it's current state I'm not sure I can trust the engine.

in your situation if you are looking to purchase I would get a general survey as well as a mechanical survey and engine oil analysis .after at least 10 hours on new oil.

[gallatin1988]

Originally Posted by Chotu

gallatin1988-

This is not backed up by any evidence or science. This is a personal belief of mine.

I have inherited plenty of old and barely used diesel engines in my time. In my opinion, as you start to put them into regular use, they kind of come back to life. I feel like the breakdowns are going to happen in the first few hundred hours after sitting a long time. Then after that, they kind of get into a groove.

OK Internet, please yell at me now. LOL

When I read your post it did jar loose a memory of having heard that many years ago.

@Chotu
Also, sorry I hope I'm not hijacking your thread. Maybe I should have started a new thread.

[gallatin1988]

Originally Posted by newhaul

in your situation if you are looking to purchase I would get a general survey as well as a mechanical survey and engine oil analysis .after at least 10 hours on new oil.

Thanks. Wise advice.

At the very least I'll get an engine oil analysis if I go through with the purchase

[Exile]

Originally Posted by gallatin1988

When I read your post it did jar loose a memory of having heard that many years ago.

@Chotu
Also, sorry I hope I'm not hijacking your thread. Maybe I should have started a new thread.

Whether it's true or not, it was relevant to my decision to refurbish the head on my diesel generator as opposed to buying a new one. So it doesn't seem like a thread hijack, to me anyway.

[newhaul]

Originally Posted by gallatin1988

Thanks. Wise advice.

At the very least I'll get an engine oil analysis if I go through with the purchase

it will be the best 50 bucks you will ever spend on a boat.

[David M]

Almost tripled the horsepower and the research vessel went from 9 knots to 20 knots. Pretty much doubled the amount of stations I could cover in a day.

[a64pilot]

Originally Posted by Cruiser2B

At work we have 3 and 4 cyl kubota based marine gensets....last one we swapped out had 31,000+hrs with nothing more than oil, fuel filter, a few alternators... was changed because of oil leaks...still ran! We have a few others the closing in on 20k hrs...no issues.

I think these Beta and others that are Kubota based will last a very long time with proper maintenance.

And people claim a Diesel won’t last unless run at high RPM.
These motors never saw above 1800 RPM, correct?

[a64pilot]

Originally Posted by RaymondR

It would not be that hard to do.



Since we have a prop in the water we already have the "brake" component of a dyno and unlike an auto engine we generally have access to the prop shaft and a measurement of the twist could be calibrated to give an output torque. Most of our engines already have a rev counter and an AD converter would digitize that parameter for computer input. About all else needed would be a fuel flow meter and perhaps an EGA.

It’s often easier than that. If a factory produced boat, then you know the prop it came with, assuming it still has that same pitch prop, if it still turns close to spec RPM, then it’s making real close to spec power.
But if it will also make hull speed, odds are it’s a healthy engine.

Diesels as they age and wear don’t usually lose much power, what happens is they become hard to start due to low compression and begin to burn an obnoxious amount of oil, but usually still make good power.

[El Pinguino]

Originally Posted by newhaul

That's why I like my md2 it can be hand cranked

as of now the only parts I don't have spares of is the md2 specific parts like the block and crankshaft , 90% of the rest will fit the md1 md2 or md3 platforms. As well as I can scavenge off of the md11 and the md17 series.
If not for that it would be stupid expensive .

MD17D on my boat.... have invested over the years on lots of spares.... most important and the two that will lead to engine replacement if you don't have them ( as mentioned by an ex MD17 owner in this thread ) are the left handed starter motor and the fresh water circulating pump.
Apart from that carry fuel lift pump, alternator, head and manifold gaskets, assorted other gaskets and stuff including some oil riser thingoes that connect to the rocker arm shafts and that you can no longer find... gift from my friendly long since retired Port Melbourne Volvo man. Seems they can fracture if removed and replaced too often.

Currently need to find the tools required for pulling and replacing the injector sleeves... I feel they should suit quite a few models.. even more modern ones.. so should not be too hard to source.

Diesel mechanics are two a penny... spare parts are not..

[Pitchondesign]

I'm not replacing the engine in my boat, but can understand why people do. I have a small coolant leak, a small Oil leak, and air is getting into the lift pump. These are easy things to fix. All I need is a new lift pump, a new coolant pump, and a new oil filter housing. Simple parts replacement will fix these issues. So, the engine manufacturer does not have a coolant pump in stock, and doesn't know when they will show up. The lift pump is not called out separately from the high pressure injector pump. The oil filter housing is in stock.

So, I had to cross reference the Westerbeke parts to Mazda parts. I found the coolant pump in Australia and had it shipped. The good news is it was cheap as it is a standard truck part. The lift pump/HP injector pump assembly from Westerbeke is $4000. The lift pump is a bolt on to the injector pump, but Westerbeke won't sell it separately. Unfortunately, there are no lift pumps for this engine anywhere in the USA. I might have found a source in the UK, but not yet assured. The price is closer to $300 including shipping. The oil filter housing is available from Westerbeke at a mere $1100. This part from China is $10 in quantity, and $276 from Dubai, but they won't ship. I'm still try to source this part.

My boat is laid up for the hurricane season, so I'm not in a rush, and the engine leaks are not severe. If these were serious issues I might feel differently. I understand why someone might want to replace a "perfectly good engine".

[puffcard]

Took out a great running Westerbeke. The number one reason I had lost of confidence. After doing two head gaskets in a year, it was needing a top end rebuild and finding parts for a 1979 engine was getting very hard, even though guys in England.

I have confidence
Easier to maintain
No losing 1/4qt oil every 8hrs
Better fuel economy
Quieter and smoother
Parts easier to get
I did lose some power 41-35

[zboss]

WE just went through this.

We did it primarily because we had "fixed" the same problem on the old engine twice in 5 years and it was at it again but worse. To do it right we needed to take the engine out completely; and once out it was "well, you should just rebuild it while you have the opportunity."

Turns out rebuilds you don't do yourself are very expensive and you still end up with a 32 year old engine that requires expensive parts that are sometimes very difficult to find and in the end might just end up with the problem all over again.

For another 6K it was a new engine for us - unlike some others we can afford it so it wasn't exactly going to impact our plans, other than losing a sailing season. However, we now have a brand new engine that won't have the same problems, is much much easier to service, and has much less expensive parts and has a worldwide distribution network. So when we do finally hit those out of the way places, we don't have to find the perfect mechanic to install all those expensive to import parts.

[malbert73]

Originally Posted by zboss

WE just went through this.

We did it primarily because we had "fixed" the same problem on the old engine twice in 5 years and it was at it again but worse. To do it right we needed to take the engine out completely; and once out it was "well, you should just rebuild it while you have the opportunity."

Turns out rebuilds you don't do yourself are very expensive and you still end up with a 32 year old engine that requires expensive parts that are sometimes very difficult to find and in the end might just end up with the problem all over again.

For another 6K it was a new engine for us - unlike some others we can afford it so it wasn't exactly going to impact our plans, other than losing a sailing season. However, we now have a brand new engine that won't have the same problems, is much much easier to service, and has much less expensive parts and has a worldwide distribution network. So when we do finally hit those out of the way places, we don't have to find the perfect mechanic to install all those expensive to import parts.

What did you install?