Why do people replace diesel engines in a sailboat?

[Paul Kelly]

I have an 18hp Volvo Penta 2002 in my 10m Westerly Storm. It's the same engine that I had in my Beneteau First 285. The Beneteau is 2.5 tons lighter than the Storm, so, rightly or wrongly, I regard the Storm as being under-engined. She takes a little while to get going under engine and a long time to stop.

I think my Storm deserves and would be better with a 28 - 30hp. That's why I would change the engine if I had the money. But then there's the prop... and I have a rather nice one. Changing the engine would also probably mean changing the prop. So more expense there. Ho hum!

The comments on Beta and tractor engines in this thread are really helpful.

[jen1722terry]

We had to make a quick decision on our Universal M-25 a few years ago. It had a gasket leak on the front pulley cover as well as a leaking water pump">raw water pump. The pump leaked because the PO had modified the 4-bolt mount to accept a new pump with a 2-hole mount. The new bolts were too small to torque properly (hence the leak), so the holes would have to be re-tapped or relocated. The mechanic wouldn't guarantee the pully cover wouldn't crack, an expensive Westerbeke part.

Another reason was the cramped engine compartment on our Cape Dory 31 made servicing very difficult.

Another reason was the difficulty of pulling out the engine from that cramped compartment. A thwart-ship teak beam made this a complicated and time- consuming task.

The last reason was the fragility of the ZF-10 transmissions. Even with frequent fluid changes, We had to have two installed in the first three years, under warranty for the second one, but still a pain as the engine had to be moved onto the cabin sole to do it.

We had some friends that had installed new Betas that were delighted with them, so we bit the bullet. $20,000+ dollars later, we're happy we did. The new mill is quieter, less smokey, the trans has a reputation for durability and the added HP is useful now and then in big head seas or trying to beat the weather home. The biggest benefit is ease of service, much, much easier on my back. And yes, it does use about half the fuel as the old one and requires less-frequent servicing.

As noted above, the Beta (like the old Universal) uses a Kubota block and major parts really do cost a tiny fraction of the Westerbeke parts.

We may have our boat another 5 years or so, at which point she'll be 40 years old. With the new mill, refinished decks and the new canvas Jenn made, she should still fetch a decent price, or so we hope.

Good luck

[Paul Howard]

I had two Volvo Penta 2002 saildrives on our 1992 catamaran. This engine was not known for its reliability when more than 4,000 hours on the clock. It had some major repair work done and one was getting hard to start and smoked and blew oil through the exhaust. I had done several repairs on the saildrives. They were raw water cooled.
New Volvo D20 engines with new saildrives were quoted as about one-third more than the cost of rebuilding just the engines, before any work on the saildrives. The new engines are slightly more powerful, are three cylinder rather than two cylinder 2002 and thus quieter and smoother running and supposedly (according to manufacturer's graphs) more fuel efficient.

The new engines fit into the engine compartments and on to the same engine beds. The old engines would have had to be removed for the rebuilding and re-installed, not much different than the installation of the new engines.

We had nearly 10,000miles to go before arriving at our home port. I thought it well worth the time and money to get the new engines. Three years later we sold the boat and the new owner said one of the major selling points was that the engines were nearly new.
I still believe I made the right decision.

[Chotu]

What an enjoyable thread to read. Thank you for all of the input. I’m not looking to replace an engine, just was very curious. Because I feel like I see a lot of them getting pulled out before they are dead. Now I see some of the reasons why.

[Aswayze]

I just recently overhauled a 42 year old YSE-8 in my boat.

Because:

-I am a very good mechanic

-I am a machinist and I have the ability to make all the daffy rebuild tools myself

-I can make and fit parts as needed in my shop

-I had the time and the warm dry place to work so digging for hard to find parts was not a huge deal.


Does that make me wise? No...

Does that make me better than someone who replaces a similar engine? Certainly not.

Does that give me a better engine? Hard to say, this one is in fine form now and I know it inside and out but is it really better than a new Beta? Probably not.

Did that save me money? Hard to say, my parts outlay was not unreasonable but if I had spent the time I spent working on the engine at work making overtime pay I could have easily just bought a new Beta engine.

I did my rebuild because I like doing that sort of stuff, I had the facility to do it MYSELF to a very high standard, and I enjoy that sort of work. If 100% of those prerequisites were not met, I would have replaced it with a new engine and not thought a thing of it. New engines are pretty much always lighter, smoother and easier to track down parts for. If you have the budget for it and new is the best option for you then you certainly should put a new engine in and motor off into the sunset knowing that smart guys like me might not be as smart as we look when the dust settles.

[BoatandBeach]

My Detroits are almost 50 years old. They still run reliably.

A full rebuild kit is $5k (each). A modern replacement engine with transmission is $30k (each). I'll be rebuilding when the time comes.

But Detroits still have a viable parts and service network. A lot of these smaller sailboat engines do not. If you are paying through the teeth for parts and/or having problems sourcing parts, it often makes sense to go ahead and repower. Especially if you repower with a Beta/Nanni Kubota based tractor block and take advantage of the non-marine-specific parts.

[Ostinato]

“My next will likely be a Beta Marine, Kubota tractor engine with parts that you can actually purchase through tractor supply houses for a fraction of the cost of the "marine" grade parts and their support will tell you what the Kubota part numbers are,”

An alternative to Beta that also uses Kabota is Nanni- a French engine manufacturer. There is a US distributor. Not sure which is better but worth a look.

[MAJICDAN]

I have a 1974 Gulfstar 53MS with the original 6.354 Perkins 120 HP motor.
It is big, heavy, and slow turning. does not put out much power, but it will last forever.
These new aluminum, highly stressed, turbocharged motors, are a good example of our throwaway society.
My boat has been around the world twice.
I have put over 8000 miles on it in the last 1 1/2 years.
It will push me up to 10 knots if I need to, but it gets very good mileage at 6 knots.
I just sailed to the Virgin Islands and back.
I filled up at St Thomas, then traveled to Puerto Rico, to Ft Pierce, FL, to Key West, To Don Pedro Island by Port Charlotte, back to the Keys and then to Ft Pierce on a little less than 150 gallons of fuel.
When I bought this boat twenty years ago the Broker said I should replace the motor.
It does not use or leak hardly any oil.
I use Amsoil synthetic, and change the oil every 800 hours.
I change the oil filter every 200 hours.
I met another sailer who had the same boat as mine. He had replaced the Perkins with a 350hp Cummins. He said now he could go 18 knots.
I think some people have too much money and do not know what to do with it.

[nwdiver]

The Volvo was quarter and dollaring me.......no nickels and dimes for those motors........the Beta is pennies to run and when needed a filter set is under $40....take that Volvo......if I had a Perkins or other of its ilk a proper total out of boat rebuild would make me comfortable......but that's not much less than a new Beta.....

I sail the PNW which means contrary winds around ripping currents, so a reliable motor is pretty important.

[Chotu]

Originally Posted by MAJICDAN

I have a 1974 Gulfstar 53MS with the original 6.354 Perkins 120 HP motor.
It is big, heavy, and slow turning. does not put out much power, but it will last forever.
These new aluminum, highly stressed, turbocharged motors, are a good example of our throwaway society.
My boat has been around the world twice.
I have put over 8000 miles on it in the last 1 1/2 years.
It will push me up to 10 knots if I need to, but it gets very good mileage at 6 knots.
I just sailed to the Virgin Islands and back.
I filled up at St Thomas, then traveled to Puerto Rico, to Ft Pierce, FL, to Key West, To Don Pedro Island by Port Charlotte, back to the Keys and then to Ft Pierce on a little less than 150 gallons of fuel.
When I bought this boat twenty years ago the Broker said I should replace the motor.
It does not use or leak hardly any oil.
I use Amsoil synthetic, and change the oil every 800 hours.
I change the oil filter every 200 hours.
I met another sailer who had the same boat as mine. He had replaced the Perkins with a 350hp Cummins. He said now he could go 18 knots.
I think some people have too much money and do not know what to do with it.

The exact same engine is what had me wondering. One of my boats (really need to choose just one) has this engine in it and yes, it's letting a little oil by when cold and smoking before it warms up but I can't imagine why I'd replace it.

[mikedefieslife]

Most boat engines live a super easy life compared to cars trucks etc.. In monos at least, they are inside, protected from all weathers. Completely different kettle of fish but I remember honda testing the CB500 motorcycle engine to over 200.000 miles with nothing but the scheduled service. Plenty of diesel engined cars and trucks run until 250.000 miles without needing major work and they are more stressed.

All that being said. The engine in my boat is over 20 years old. Unknown installation date, unknown hours, unknown service history. I maintain it, but won't through money at it. When it dies, it dies, and I will replace it with a outboard(s) of similar power and save 150kg of weight.

It's a shame there is no super easy way to dyno our engines to see how much power they've lost over the years.

[Cliffhanger]

I bought a sailboat with a mid 80's Volvo Penta that was covered in rust, difficult to start and blew a lot of smoke. Replacing the engine was factored into the price of the boat. I decided to pull the old engine out myself partly to save some cash but mostly to learn something about diesel engines in the process. I figured it was easier to pull it apart on the boat and remove the bits rather than remove the whole engine in one go. To cut a long story short I found that the engine was actually not too bad internally. Still on original main bearings and crank journals within spec. The biggest problem was pitted valves and stuck rings. So, I decided to rebuild rather than replace. I had the heads reconditioned, one new valve, injectors overhauled, new rings and repainted the outside of the engine. Total cost was about $3000 instead of $20,000 for a new engine. Many hrs of labour because I was learning as I went along. Was it worth it? Yes because I now understand how the engine works, inside and out and saved a lot of money. If I had paid someone else to do it, I would have learnt nothing and probably paid 1/2 to 3/4 the cost of a new engined. Repowering would have been a better option then.

[malbert73]

I repowered to replace a 30 year old 3600 rpm 44 hp with a beta 50. Cruise at 1800rpm is much quieter and relaxed. Exhaust much cleaner. So the old engine ran ok but the new one is a true enhancement

[Cthoops]

We replaced our Yanmar SB 12 with a Beta 16. The Yanmar worked but it had an unknown number of hours, unknown maintenance history, some parts were impossible to find, and as a single cylinder it was ear-splittingly loud and shook the entire cockpit. We were going cruising and didn’t want to risk having it finally did in a place where it would be substantially more difficult to replace.

Our new Beta is quieter, lighter, smaller, more powerful, and uses less fuel. Perhaps most importantly, when we are motoring between a cut with reefs on either side of us, we aren’t thinking in the back our minds “I wonder if this is the moment the engine is going to finally give up the ghost.”

[RaymondR]

Originally Posted by mikedefieslife

It's a shame there is no super easy way to dyno our engines to see how much power they've lost over the years.

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.