Bullet Proof Diesel

[TeddyDiver]

Well you asked for BULLET PROOF https://www.fieldmarshalengine.com/p_marine.htm

[Cheechako]

I'm not a big fan of Yanmar's, but I don't think they are prone to seizing... there are just a lot of them out there.
I don't know if there are any "bullet proof" diesels anymore. In their day the Perkins line and the Volvo MD2B type were close IMHO. But that doesn't mean people didn't have problems now and then!
Be sure to find an older one that is fresh water cooled , that will help to eliminate some issues I imagine.

[skipmac]

For bulletproof the classic GM 6-71 was hard to beat. Noisy and not terribly efficient but would run forever.

Would probably be just a bit too much for most sailboats.

[captain58sailin]

I got a 471 Detroit that I am pulling out this month, runs good, plus a 506 twin disc reduction gear for sale. Don't like the noise or the slobber, but it always starts and will run as long as you get fuel to it.

[goboatingnow]

Most modern diesels are " bullet proof ". Follow the recommended service procedures. Use them regularly. Most diesels don't die but are rather murdered.

Dave

[hellosailor]

Is being bullet-proof engine, is being demand for bigger bullet.(G)

Some decades ago Consumer Reports did a reliability review of 35mm SLR cameras. They went around to the big repair shops and took head counts and downgraded Nikon because there were so many being repaired.

And not so long after, they confessed that might be a mistake, since "all" the pros still were using Nikons, using them and abusing them and they'd go take a job in the rain and then drop the camera off for repairs routinely. Which home users simply didn't normally do.

So, lots of seized Yanmars? Could mean lots of Yanmars on the market, or, lots of uneducated owners (i.e. first timers) buying cheaper boats, equipped with Yanmar engines, or something similarly not related to the engine quality. No way to tell without doing a LOT of research on those owners and engines.

Find a boat you want, and then IF there are at least two under consideration, ask which engine is in each one. FQC or raw cooled as well.

[marlinmike]

For a sail boat I really like Yanmar, parts availibility, ease of use, everything, not sure where the siezing thing came from, some of the larger sport boat levels had issues, but it was resolved.

[Ex-Calif]

Originally Posted by goboatingnow

Most modern diesels are " bullet proof ". Follow the recommended service procedures. Use them regularly. Most diesels don't die but are rather murdered.

Dave

Yup...

I guess there can be multiple versions of "bulletproof"

- Engine 1 - Runs every day for 8 hours at 70-90% of the power curve
- Engine 2 - Runs 10 minutes twice a weekend at 50% to push the boat in and out of the slip
- Engine 3 - Runs 2 hours everyday on 21 day passages at 25% load to charge the batteries
- Engine 4 - Doesn't run for 21 days and is fired up for 20 minutes to dock after a passage.

Everyone has their opinions and lore about diesel engines.

I think the only "happy" diesel is Engine 1.

Now convert those usages to "years of useful" service?

- 5?
- 20?
- 15?
- 30?

For boats 2-4 engine hours are effectively meaningless... The calendar kills you because of corrosion, seal breakdown etc. etc...

For boats 2-4 there is a lot to be said for electric power and a genset/solar excpet...

Weight of solar/batteries, complexity of genset and space for both.

Diesel fuel is realtively safe as a hydrocarbon and hydrocarbons are still the biggest bang for the "volume/weight" buck

[perchance]

Originally Posted by goboatingnow

Most modern diesels are " bullet proof ". Follow the recommended service procedures. Use them regularly. Most diesels don't die but are rather murdered.

Dave

They mostly die from neglect and improper operation.

[Adventurebound]

The last time I asked a diesel how happy it was, it was one that ran at a very slow rpm, had a very big heavy casting and sat patiently in the bottom of a boat for decades.

[Ex-Calif]

Originally Posted by Adventurebound

The last time I asked a diesel how happy it was, it was one that ran at a very slow rpm, had a very big heavy casting and sat patiently in the bottom of a boat for decades.

Was it happy?

Or lonely and sad - LOL...

There is a big paradigm shift with the Yanmar's. Old timers are "very" reluctant to push them past 2,000 rpm.

I was skippering a friend's boat, pushed the Yanmar up to 3200 or so (3600 R/L?) - I thought he was gonna throw me overboard.

"Diesel's like to run slow! No higher than 2,000 RPM. And only that when you are being chased by pirates! BTW any idea why my exhaust and injectors are fouled with black soot?"

[Curmudgeon]

Originally Posted by goboatingnow

Most modern diesels are " bullet proof ". Follow the recommended service procedures. Use them regularly. Most diesels don't die but are rather murdered.

Dave

Exactly. Every name brand diesel will give you 4,000 hours if well maintained and used properly.

Diesels like to run continuously, and most diesels have a "sweet spot" between 1,900 and 2,200 rpms at which they will run forever.

[TacomaSailor]

The diesel engine dealer that maintained my Yanmar for 10 of the last 19 years sells several types of diesel and has supported the commercial fishing fleet in Puget Sound since 1968. They also sell, repair, rebuild, and maintain diesels installed in heavy dirt movers, farm equipment, land based power generation.

They tell me they have thousands of Yanmar Marine 4 and 6 cylinder diesels installed in boats operating as recreational and commercial vessels.

He says Yanmar are bullet proof and will do 10,000 hours IF

- they are run at 70% - 90% of 24-hour rated power e.g. my 4JH2E would be 2200 t0 2900 RPM

- run the engine at 24-hour rated power for 5 minutes every three to five hours - my engine that is 3200 RPM

- IF you start the engine - run it up to full operating temperature for at least five minutes

- when shutting down the engine - IF it has been running at less than 80% power - then run it at full power for 10 seconds in neutral and then let it slow for another 10 seconds

- change the oil

- keep the air filter clean

They said no Yanmar ever fails if operated in the manner shown above

PS - their mechanic installed new injectors at 400 hours. He wanted to demonstrate to me how fast a Yanmar NA 4 will run and how smoothly it ran. He pegged the tach for (4000 RPM) for 10 seconds and said the engine was probably doing 4200. I moved to the side deck outside the cockpit with pictures of dancing rods appearing in the cockpit.

He has strobed 4JH engines at 4400 RPM. His last statement "Yanmar loves to run fast and hot - it makes them happy."

That was in 1995 and my 4JH2E is still running fast and happy with only oil changes, new water pumps, and valve adjustments. I have about 2800 hours on the engine and almost all of it has been 2300 - 2700 RPM.

[avb3]

Of the common diesels you find out there, many are good.

Be aware though, Volvo has a particular propensity to be significantly higher for parts and their longevity and reliability has been questioned by numerous owners.

An important consideration, as others have pointed out, is where are you going to be cruising, and what is the availability of parts?

[GILow]

If you are buying an older boat (20+ years) in Oz there's a good chance you will run into engines marinised by Diecon in Qld. All I have read and now experienced of those conversions is positive. The seem to have gone out and sourced engines with good reputations and low mileage for their conversions. Lots of different makes and models.

Matt