New inboard

[jpope66]

HI Gang. I am new to this forum. Looking forward to the discussion. My wife and I will be retiring soon and we have decided to purchase a 35- 40ft trawler. I would love your input on which brands of inboard diesels engines would you suggest to purchase if the boat I buy needs one. Thanks in advance.

[RT Firefly]

Greetings,
Welcome aboard. Why look for a vessel that needs re-powering? Such an exercise might cost you tens of thousands.

[Comodave]

Welcome aboard. I would advise not looking at boats than need new engine(s). The cost to repower twin engines can get up into the area of $75K depending on the power of the engines and complexity of access to the engines. Buy something with good engines and this is coming from a die hard DIYer. Good luck and have fun with the search.

[Slowmo]

As stated above I would avoid a boat that needed repowering, especially when so many boats have twin engines. Typically you would replace both the engine(s) and reverse gears, so the costs are many tens of thousands of dollars All that said, if you do have to repower, the best engine depends on what size/hp engine you would be looking at. Pay close attention to the manufacturer's service network and reputation for supporting old engine models. Boat engines have a very long service life, the value of the boat is hurt if it has an engine that is difficult to get parts for. Companies like Caterpillar support old engine models, others like Volvo aren't so good in that respect. You want to focus on manufacturers with a good track record of supplying and supporting marine installations.

What works best would be a function of how much power is required and any physical constraints (e.g. height). Many new 35-40' boats use Cummins meaning support is widely available. John Deere also has a strong reputation and a wide product line. Obviously Yanmar is well known as well.

[BruceK]

In older boats consider Ford Lehman, Perkins, Cummins, Hino. These non exhaustive examples of engines seem to last well, with parts and service relatively available, though older can mean searching for parts. Avoid engines needing repair/replacement.
And of course there`s much more to selecting a boat than engines.

[FF]

Most trawlers are 5K to 8K (depending on LOA) displacement boats.

A marinized diesel will usually last 5000 to 8000 hours perhaps more.

As many boats only operate about 200 hours a year , a repower is seldom needed.

These engines can be killed by poor operation or lack of maint , but its not that common.

Find a boat that suits your desirements and a surveyor.

[jpope66]

I guess as a future buyer I would like to avoid purchasing someone else's headache. MY philosophy is go new on the engines then I know that the maintenance records would be correct. I am willing to pay the extra money for the peace of mind. I like the idea of a surveyor for added protection. I really appreciate everyone's suggestions!!

[Pete Meisinger]

If the boat you decide to buy needs an engine. Decide to buy a different boat.

pete

[Nomad Willy]

I basically did that.

In so doing I learned a lot, got what I wanted and due to luck and other variables am very happy how things turned out.

It’s more complicated than this but we were about to move to a small town in SE Alaska so wanted a well proven product that could be depended on. Looked at Vetus, Westerbeke, Yanmar, Kabota and even Volvo.
I found out that FD boats need X amount of power. 5-10 hp too little and your’e underpowered. 5-10 too much and you’re overpowered. They can only go so fast and the amount of power is quite easily determined.
Observing other boats of the same weight and length can be an eye opening adventure. Assign them all a weight to power ratio. My Willard is 5hp per ton. And she’s a bit overpowered. 4hp per ton would do just as well and usually close to 3hp per ton will leave one going the same speed and burning the same fuel. Fuel burn seemed an important issue to me early on but now I mostly don’t care.

My engine choice was Klassen. A marineizer in BC Canada. The specific engine a Mitsubishi S4L2 rated at 37hp at 3000rpm. I retained the original BW 2.57-1 drive and prop. Willard over propped their boats as did most manufacturers at that time so I took out an inch of pitch and went from 2750rpm WOT to 3000rpm at WOT. Perfect.

I replaced batteries and fuel tanks w aluminum.

I chose new electronics as not much came w the boat.

The engine is not one of the popular brands (Mitsubishi) but think my engine is as good as the most popular brands. My coolant contacts no aluminum mostly because the exhaust manifold is steel. A special alloy to minimize corrosion. Klassen has been using this manifold since the 60’s marineizing engines for fishing boats. Only needed to replace one due to corrosion. Noted about 15 yrs ago.

So my refit - repower turned out very well.
And I got what I wanted. And at a good price.
I beat the odds and used an engine few have heard of on TF.
So I can tell you a popular engine recommended by 101 gurus isn’t necessary. But a good track record is.

[Flyguy1967]

I agree. If you are looking at a boat that need a repower, keep looking. I just went through that and you will be money ahead to find the cleanest, most updated boat you can afford that gets the mission accomplished.

[FF]

"I am willing to pay the extra money for the peace of mind."

In the long run a brand new boat would probably be cheaper.Or dealer demo.

The problem is , except for some work boats ,engine changes were never planned for , so are insanely expensive .

[Bacchus]

I'm in the same camp as others responding.
If you look at boats that are close or need repowering they will likely be misused or poorly maintained unless it is very old as most marine diesels have a very good service record.
I think I would take the same budget you would spend for a boat and repower and purchase a newer boat that has been better cared for and if you want more confidence have a good mechanic / rebuilder go through the engines and related coolers, pumps, etc to confirm they are in tip top shape.
My impression at least is that there are many more issues with these related systems than the engine itself.

[jgtrucking]

Originally Posted by FF

"I am willing to pay the extra money for the peace of mind."

In the long run a brand new boat would probably be cheaper.Or dealer demo.

The problem is , except for some work boats ,engine changes were never planned for , so are insanely expensive .

Tank replacements are likely to be nearly as problematic as engine replacements. If the boat is older, you likely would be changing gears along with engines. The closest thing to peace of mind would be a new boat, or very nearly new.
Even if you buy an older model and have trouble down the line, a rebuild of your existing iron is many times simpler than a repower.
Imho, figure out what you want in a boat first. Narrow that down with the must haves, like to haves, etc. When you have the boat narrowed down, you will likely fi d the best value option not needing the things being discussed here.

[jleonard]

I repowered a single engine boat and it was one of the best things I ever did to a boat. It made it a whole new boat.
The boat was an old 34 ft Mainship Nantucket model 1.
Replaced the OEM Perkins 160 with a new Cummins 6BTA and new gear.
More power, much better speed and economy with zero worries for the 6 years I owned it after the repower.
Gave me much better "weekend range".

[Soo-Valley]

Originally Posted by Nomad Willy

I basically did that.

In so doing I learned a lot, got what I wanted and due to luck and other variables am very happy how things turned out.

It’s more complicated than this but we were about to move to a small town in SE Alaska so wanted a well proven product that could be depended on. Looked at Vetus, Westerbeke, Yanmar, Kabota and even Volvo.
I found out that FD boats need X amount of power. 5-10 hp too little and your’e underpowered. 5-10 too much and you’re overpowered. They can only go so fast and the amount of power is quite easily determined.
Observing other boats of the same weight and length can be an eye opening adventure. Assign them all a weight to power ratio. My Willard is 5hp per ton. And she’s a bit overpowered. 4hp per ton would do just as well and usually close to 3hp per ton will leave one going the same speed and burning the same fuel. Fuel burn seemed an important issue to me early on but now I mostly don’t care.

My engine choice was Klassen. A marineizer in BC Canada. The specific engine a Mitsubishi S4L2 rated at 37hp at 3000rpm. I retained the original BW 2.57-1 drive and prop. Willard over propped their boats as did most manufacturers at that time so I took out an inch of pitch and went from 2750rpm WOT to 3000rpm at WOT. Perfect.

I replaced batteries and fuel tanks w aluminum.

I chose new electronics as not much came w the boat.

The engine is not one of the popular brands (Mitsubishi) but think my engine is as good as the most popular brands. My coolant contacts no aluminum mostly because the exhaust manifold is steel. A special alloy to minimize corrosion. Klassen has been using this manifold since the 60’s marineizing engines for fishing boats. Only needed to replace one due to corrosion. Noted about 15 yrs ago.

So my refit - repower turned out very well.
And I got what I wanted. And at a good price.
I beat the odds and used an engine few have heard of on TF.
So I can tell you a popular engine recommended by 101 gurus isn’t necessary. But a good track record is.

There are so few mariners left, the boaters are taking over.

[jpope66]

Thanks!

[rgano]

Putting a new diesel engine in a used boat just because you want the peace of mind on new and known is unnecessary if you shop properly. It is not really that hard to determine whether a given marine diesel has been properly cared for.

[FF]

"It is not really that hard to determine whether a given marine diesel has been properly cared for."


An seller with a decade or two of oil sample reports makes it easy.

[NUTIN FANCY TOO]

Detroit Diesels are a little loud,but,last forever,and parts are easy to come by.
I have twin 4-71's in my 1969 42FT Grand Banks, and i expect that they will outlast me,and,probably, tbe next owner.

[Mako]

Even a 2-71 would be over powered in the typical 35-40ft trawlers the OP is looking for. Perhaps he can hunt down a 1-71. Tough to find, but if the boat has enough vertical clearance in the engine space (for a single) then that little engine could take him to the moon and back.

That would be fun!