Reliable Old Diesel engines

[Bill_Giles]

Our Volvo Penta MD2030 of 2003 is very reliable. Over the years it has has new water pump seals and that is about it. It does about 200hrs a year. The only time it stopped on us was when diesel bug blocked the filters.

The only downside to the Volvo is the cost of spares. Volvo have a magic green paint which they put on all their parts which doubles or trebles the cost.

[Icarus]

Direct injection diesel engines, non turbo, are preferable to a common rail injection in my opinion.
Some diesel engingines are designed better than others..piston kip, quality of castings and so on.
My, now 40 year old 3AB1 ISUZU never missed a beat, two years ago I had the cylinder head and injector serviced, installed a Denso starter motor and a new100A alternator.
Gearbox is a Twin Disc p60 2:1 driving an Autostream 17x12 three bladed feathering prop...6.3kn at 2400 RPM/ 12T 40ft mono hull..
Considering 20k plus for new engine, I would prefer to rebuild the engine barring a catastrophic failure
Keeping up with regular oil and fuel filter changes are a must.

[kmacdonald]

I'd be very disappointed in a diesel that died with less than 10,000 hours. 20 to 30k hours is a realistic figure. Don't confuse periphery parts replacement with a bad engine. Water pumps, alternators, belts, hoses, injectors, seals, glow plugs, heat exchangers, oil and trans coolers, etc can fail but don't assume the engine is bad. A lot of those things are basic maintenance and not crazy expensive.

[newhaul]

Originally Posted by Saltysaltsalt

Hey so I'm looking at some boats that have universal or yanmar diesel engines that are 30 years old or more. In the world I'm coming from with outboards a 30 to 40-year-old motor is kind of ridiculous.

Let's say these old diesel engines have been pretty well taken care of and someone like a surveyor looks at it and says it's in decent or good shape. Is this the kind of thing where I'm going to constantly deal with parts breaking down or I might go a few seasons with literally nothing but maintenance?

Also if your budget put you in sailboats that are in the 30 plus year old class are there particular engines you would or would not want to deal with?

Ok here is the long and short of it all ..
Diesel engines require 3 things to basically run forever.
Clean oil
Clean air
Clean fuel.

Now when looking to purchase along with the boat survey get a mechanical survey which includes an oil analysis. This will tell you about the maintance of and condition of the engine .

[Bill_Giles]

You should also check cylinder pressures. And while the injectors are out put an inspector scope in the cylinder for a look - just because you can.

[newhaul]

Originally Posted by Bill_Giles

You should also check cylinder pressures. And while the injectors are out put an inspector scope in the cylinder for a look - just because you can.

Hence mechanical survey.

[Rob19321]

Originally Posted by granche1

My Weterbeke 46 is 38 years old. It is based on a Mitsubishi forklift engine. She ticks along nicely. Westerbeke parts are stupid expensive though. If i have to replace, I would look at Kubota.

Isn't the Westerbeke, the same as Universal, and then they're the same as Kubota?
I couldn't tell if you meant Westerbeke and Unversal were two separate options.

[kmacdonald]

Westerbeke used different base engines.

[mvweebles]

Originally Posted by Icarus

Direct injection diesel engines, non turbo, are preferable to a common rail injection in my opinion.

Very common sentiment in the boating community require context. It implies the new engines are less reliable and perhaps less efficient. Not true. I say that as someone who prefers old-school engines because they are easier to fix and I'm not the best mechanic.

What's interesting is 20+ years ago when Tier 3 engines hit the trucking industry, the old-school independent OTR operators were saying the same thing - old engines are better. But then they started to compare notes with the newer fleets. Newer technology was incredibly reliable and burned 10% less fuel in the process. Within a few years, the old engines were gone not because they had worn out, but because the new ones were better and less expensive to operate.

An old-school natural suits me better. But that doesn't make it a better engine - just a better engine for me and how I use my boat.

[newhaul]

Originally Posted by mvweebles

Very common sentiment in the boating community require context. It implies the new engines are less reliable and perhaps less efficient. Not true. I say that as someone who prefers old-school engines because they are easier to fix and I'm not the best mechanic.

What's interesting is 20+ years ago when Tier 3 engines hit the trucking industry, the old-school independent OTR operators were saying the same thing - old engines are better. But then they started to compare notes with the newer fleets. Newer technology was incredibly reliable and burned 10% less fuel in the process. Within a few years, the old engines were gone not because they had worn out, but because the new ones were better and less expensive to operate.

An old-school natural suits me better. But that doesn't make it a better engine - just a better engine for me and how I use my boat.

Don't forget they still run after a lightning strike as well

[Jim Cate]

Within a few years, the old engines were gone not because they had worn out, but because the new ones were better and less expensive to operate.

Of course, when one of the OTR engines does falter, they pull to the side of the road, whip out their telephone and lo, pretty soon another big truck comes along and fixes the fault or hauls them in to the depot where an expert on those engines hangs out. He knows that engine inside and out... and has the factory tech on speed dial for the awkward issues.

Not quite that easy for the cruising yottie, whereas most simple old fashioned engines can be fixed by the owner or any competent mechanic... even in the islands.

Jim

[Briis]

If you're a first-world-only sailor, with high-end electronic diagnostics benches, service points and specialized dealers nearby - by all means go for the modern complex high power efficient diesels.

But for me, cast iron head, mechanical pump and non turbo is a must. This limits choices indeed, but thankfully some are still making those.

Yes, less efficient - less power, more weight - but can be repaired in the "bush" unlike the modern common-rail, force turboed and intercooled electronically controlled diesel counterparts that have warp-prone aluminium alloy heads to save weight and to have better cooling due to more heat the forced breathing creates (potential problems doubled, let alone turbo and intercooler themselves are suspect in long-term running in the remote third-world sailing conditions with poor quality diesel, low quality local oils and very limited service and repair facility options). More like quadriple the future-arising problems for me.

In this view, having +10% fuel consumption, +15% the weight and -30% the power is a very small price to pay for the simplicity and long-term running of go-anywhere repair-anywhere run-without-electricity diesel engine.

I've currently got an old Mitsubishi 4DR5 (WW2 Jeep based) marinised engine and it's just staggeringly more robust and easier to work on than any modern complex high-power compact Yanmar I've seen. Probably well over 8K if not over 10K hours (hour meter was worn out a decade ago!) the only constant problem I have from a 37 year old engine is a small but annoying oil leak to bilge.

If I'd replace it someday I'd definitely go Kubota or Mitsubishi based route (Beta, Sole, Drinkwaard and Nanni use those to my knowledge) on the above-mentioned spec and reasoning.

[Tia Bu]

Old inboards rust out. They don't wear out. If I'm looking at a boat with a 25 year old engine, I count on having to replace it or rebuild it at some point. And that point is unpredictable. Hours and maintenance history haven't been good predictors for me or my friends in the past. An inboard is a big hunk of iron sitting in salt water, with salt water in it, for a quarter century. And it sits (not running) most of that time. Sooner or later, something will rust out that's the final straw.

New engines are great and have a predictable cost. Rebuilding is cheaper and easier if it's an option.

Run an old engine as long as you can, but budget to replace it. Or buy a boat from someone who already has. IMHO. But this is based on long experience.

[newhaul]

Originally Posted by Tia Bu

Old inboards rust out. They don't wear out. If I'm looking at a boat with a 25 year old engine, I count on having to replace it or rebuild it at some point. And that point is unpredictable. Hours and maintenance history haven't been good predictors for me or my friends in the past. An inboard is a big hunk of iron sitting in salt water, with salt water in it, for a quarter century. And it sits (not running) most of that time. Sooner or later, something will rust out that's the final straw.

New engines are great and have a predictable cost. Rebuilding is cheaper and easier if it's an option.

Run an old engine as long as you can, but budget to replace it. Or buy a boat from someone who already has. IMHO. But this is based on long experience.

Not many of those old raw water cooled left most that are still here have been upgraded with fwc. Or they were designed that way from the start as most are maranized tractor engines . My mitsubishi k2b based westerbeke 10-two is still like new and it's 40 years old.

[mvweebles]

Originally Posted by Jim Cate

Of course, when one of the OTR engines does falter, they pull to the side of the road, whip out their telephone and lo, pretty soon another big truck comes along and fixes the fault or hauls them in to the depot where an expert on those engines hangs out. He knows that engine inside and out... and has the factory tech on speed dial for the awkward issues.

Not quite that easy for the cruising yottie, whereas most simple old fashioned engines can be fixed by the owner or any competent mechanic... even in the islands.

Jim

And that's why I will likely always own an old naturally aspirated diesel.

But my point is that new common rail diesels are not nearly as drama-filled as sailors (and trawler owners) make them out to be. Sure, an OTR trucker may have better access to repair than a mid-ocean boat, but financial consequences of a failure are very steep - especially for independent drivers who are more likely to do their own work and do not have a fleet to syndicate risk across. In any given year, they put 100x the hours on their diesel as all but a few recreational boaters do.

If modern diesels were so fragile, there would be a LOT more old diesels on the road. Emotionally, I'm still tied to my old Perkins. Intellectually, it's a dinosaur's argument.