Reliable Old Diesel engines

[Mrkva]

Volvo Penta 2003, 1700 hours on tacho, made in 1985, boat was made in 1986.
Diesel maintenance done since 2020:


* Changed coolant
* Changed cooling water seacock (original one was gate valve grown shut with barnacles)
* Changed saildrive diaphragm (original one was from 1986 and it started to leak)
* Adjusted valve clearance once
* Changed oil, filters, and provided it with fresh diesel
* I need to change valve cover gasket, it leaks a bit of oil when running

Granted, she smokes a bit, especially when cold and tends to occasionally die just after starting when warm (when starting without the cold-start startup magic), but other than that there were no problems at all. Took her for a canal journey with dozens of starts each day, and she still purrs like a kitten. I might pull the injectors this/next season to alleviate the smoking, but honestly, it's quite low on my todo list.


Before buying the boat, I had no idea if the diesel even runs and was quite suspicious about it (the coolant tank was empty, the saildrive seal leak was obvious, etc...), so I was researching options on repower. Now I'm starting to thing that that diesel will outlive me.

[deblen]

Originally Posted by Mrkva

Volvo Penta 2003, 1700 hours on tacho, made in 1985, boat was made in 1986.
Diesel maintenance done since 2020:


* Changed coolant
* Changed cooling water seacock (original one was gate valve grown shut with barnacles)
* Changed saildrive diaphragm (original one was from 1986 and it started to leak)
* Adjusted valve clearance once
* Changed oil, filters, and provided it with fresh diesel
* I need to change valve cover gasket, it leaks a bit of oil when running

Granted, she smokes a bit, especially when cold and tends to occasionally die just after starting when warm (when starting without the cold-start startup magic), but other than that there were no problems at all. Took her for a canal journey with dozens of starts each day, and she still purrs like a kitten. I might pull the injectors this/next season to alleviate the smoking, but honestly, it's quite low on my todo list.


Before buying the boat, I had no idea if the diesel even runs and was quite suspicious about it (the coolant tank was empty, the saildrive seal leak was obvious, etc...), so I was researching options on repower. Now I'm starting to thing that that diesel will outlive me.

2003 injectors are in a copper tube. Pulling them could unseat the copper tubes. I have never dared to remove mine yet (2400hrs original 1984),because special tools are required to crimp new tubes into head.
Suggest you read repair manual & many posts on internet,youtube & CF,etc. about this before removing injectors.
Blue smoke,at startup,could be valve seals.

I removed my head,took it to a machine shop,had valves & seats ground(better starting) & new valve seals. Re-installed head myself with new decarb gasket set. Injector tips are visible with head off.I gave the tips a LIGHT scrape cleaning. Also replaced all rubber seal rings on copper cooling tubes,cleaned pipe and sockets to shiny,& reassembled pipes carefully,in the correct order & per the book. Working fine since./Len
https://ab-marineservice.com/wp-cont...SHOPMANUAL.pdf

https://www.youtube.com/watch?v=iveMg6UhDFo&t=572s

[sailingunity]

Originally Posted by deblen

2003 injectors are in a copper tube. Pulling them could unseat the copper tubes.

If you're taking your head to a shop anyway, don't worry about unseating the tube, they can pressure check and reinstall them if needed. Better to remove the injector so you can have them rebuilt.

[Mrkva]

Originally Posted by deblen

2003 injectors are in a copper tube. Pulling them could unseat the copper tubes.

Yes, worried it will put me out of comission for weeks/months is exactly why I haven't pulled mine yet, and why it's so low on todo list.

[Rob19321]

Finally after years of reading posts, I can contribute.
Concurring with most everyone above.

I own both a Yanmar and a Universal

1. 1979 Yanmar 2QM15, 2 Cylendar, 15 horsepower, no glow plugs, on a ODay 30 at 10,500 pound.
(In a related note, a friend has the same boat which optionally came with a Yanmar YSM8, Yanmar single cylendar, 8 horse power. They found it to be under-powered and upgraded to a Universal M30 24 horsepower. His reasoning, the 8 was just sufficient enough but wouldn't get them out of a problem situation in storms or high wind. Never once suggested it was over powered)

2. 1984 Universal M25, 3 Cylendar, 23 horsepower, glow plugs, on a ODay 34 at 11,500 pounds.


Observations,
Yanmar died a year or so after buying it in 2016.
Full rebuild $7000 Canadian (Roughly $5200 US) at 39 years old (Sorry no hours meter)
Strong and pull 10,500+ fine so that ratio noted above, 2hp/1000 pound seems like a good benchmark.

Universal seemed to have issues from the start, I'd submit that's not engine fault but years/decades of whatever happened / deferred maintenance.
- Hard Starting - cranking 15+ seconds. (Found the infamous "trailor connector" corrosion and cut it out, 5 second cranlking to start now. Amerage was bleeding to resistance in connector )
- Inconsistent idling - replaced low pressure fuel hoses, and was replacing the electric fuel pump only to find corroded conntectors. (Surprise?) Replaced and now solid.
- at 40 years old, I was planning to rebuild this winter. Talked out of it after finding solid compression. Will probably replaced anchilary or peripheral items this year and keep on running. (Starter, relay, alternator, maybe high pressure fuel lines.)
Strong and pull 11,500+ fine so that ratio noted above, 2hp/1000 pound seems like a good benchmark.

All 4 combinaitons considered;
8hp Yanmar on friend's 10,500 boat was (barely) sufficient
15hp Yanmar on my 10,500 boat was (easily) sufficient
24hp Universal on friend's 10,500 boat was strong and I think he towed me once for 30 minutes
23hp Universal on my 11,500 boat is strong and my troubleshooting and fixes all concur with comments above to "...as long as it is maintained," its a solid platform.

Whew... so happy to share after learning from everyone.

[JBsurfin]

Originally Posted by Mike OReilly

My old Perkins 4108 is going on 40 years old. The engine itself has been rock-solid for the 13 years I’ve owned her. I’ve had to replace or service many things around the engine, like pumps, filters and alternator. But the engine itself has never been a problem. I think you could hit it with a shotgun blast and the damn thing would keep running.

Have the same findings with my orig 108 in my 83 dickerson. Just basic maintenance and normal replacements. Parts are always available.

[svfinlandia]

Originally Posted by Mike OReilly

My old Perkins 4108 is going on 40 years old. The engine itself has been rock-solid for the 13 years I’ve owned her. I’ve had to replace or service many things around the engine, like pumps, filters and alternator. But the engine itself has never been a problem. I think you could hit it with a shotgun blast and the damn thing would keep running.

Same for my Perkins 4.238.
Over 3000 hours and still going strong. Starts immediately and runs smooth as silk and is reliable as a Rolex.

Al, S/V Finlandia

[parkstone bay]

A yacht diesel that's been fed on a diet of clean air, and clean fuel, and clean lube oil will see you and me out.
Very very few leisure marine diesels die from over-use, nearly all die from underuse and/or lack of basic maintenance. (Change the fuel and oil filters, and change the sump oil, at the recommended intervals or shorter)
Problems arise when these very basic issues are ignored : it's always some excuse like "it's difficult to remove the dipstick or access the oil filter .......", it's never CBA. If you fail to carry out basic maintenance, and, sad to say, some people do fail, that's entirely your lookout.

[gulfislandfred]

My list of good engines,based on my own experience, and availability and price of parts.



Kubota/Universal/Beta (if it's a Kubota block)
Parts are available from Kubota tractor dealers, world wide. Easy to work on.
There are other motors that use a Kubota block. I would consider any of them.


Isuzu
Parts available, but, of all the engines, owners report that the Isuzu runs pretty much forever, with no need to do any repairs. Just change the oil and give it clean fuel. Isuzu is known to vibrate a lot at certain RPMs.

Yanmar
Reliable, long lived (even the raw water cooled ones, but FWC is better.)
I'm hearing that parts are harder to find in Canada recently.


Perkins:
Strong, reliable, parts available. Be sure to carry a spare raw water pump. There's a pressed on metal drive connector that breaks, and it's hard to fix on the boat, even if you have the spare part. They tend to smoke, and have oil and fuel leaks.

[Pete7]

Originally Posted by Mrkva

Yes, worried it will put me out of comission for weeks/months is exactly why I haven't pulled mine yet, and why it's so low on todo list.

The one check you should do is pull the exhaust manifold and check to see if its blocked, which they do. They can be cleaned out but chances are you will break through the cast iron wall. Replace with stainless steel.

https://www.ebay.co.uk/itm/234818937...UaArkDEALw_wcB

[FoxIslander]

Most old diesel engines are quite reliable if reasonably maintained. One old diesel I would personally avoid is the VW Pathfinder. Unless a decision had been made to replace it.
Very difficult sourcing parts and has a timing belt.

[Jimmyhenry]

Our Perkins 4-236 is 49 years old. Starts every time. Hardly need to crank more than 2 or 3 seconds. Never smokes.
All the earlier comments about these engine are spot on.

[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.

[girdasso]

i have had Volvo, Perkins 4102 and Yanmar engines in my boats and my experience favors Yanmar as the best engine. My present yacht has a Yanmar just coming up to 5000 hours and has never missed a beat or failed to deliver. It is serviced once or twice a year by a very good diesel engineer.

[BayouSailing]

One of my favorite engines to work on is a 1941 MECO diesel.

It's in a customer's boat of the same age, built in SE Louisiana as an oil seismography crew/quarters boat.

I've been the maintainer for 6-7 years, first job was as a diver on the drive shaft, then when they hauled out (for the first time in 25 years) I got the plumbing portion of the haulout. Changed every thru-hull, or eliminated by replanking or plugging the ones no longer needed.

BEFORE that, probably 10-12 years ago, the vessel sank in it's slip due to a valve being left open (suspected cause). The engines were pickled, starters rewound, and it was running within weeks.

As a result of that, over time, the injector pump locked up about two years ago. NO one on record realized it was self-lubricated from it's own small sump, not connected to crankcase engine oil. It took a can of brake cleaner and two toothbrushes to clean the paint from the clearly made label that said CHANGE OIL EVERY 100 HOURS. None of the family knew.

The injector pump is an American Bosch pump found on old MACK trucks. We had it serviced, they noted one broken spring and a lot of chrome missing from the camshaft (in the pump). They had another spring in a pile. I've been after them (the family) to rebuild the other one while the current rebuilder still lives. Otherwise we're in a pickle.

But the engine itself is SOLID. Completing a rebuild of a circulating water pump right now (a keel cooler leaked. So they topped off with river water for over 10 years, maybe 15. This ate the roll-pin that coupled the impeller to the shaft, so the impeller wouldn't turn and the engine was giving weird overheat symptoms. After more testing than necessary they allowed me to pull the circulating pump and WHOOP, THERE IT IS just a broken shear pin. And a bit of wear on the shaft and the impeller from rattling around in the cavity. Some time at the machine shop and back on board.

Mind you, in this application, the circulating water pump weighs 41lbs and it's shaft, driven off the timing gear/crankshaft, proceeds all the way through the circulating pump (heading towards flywheel), and the injector pump is driven off the same shaft.

AMAZING in it's simplicity. Could be made to run in almost any condition, and probably on any fuel.