I know some have heard this story before but it applies to this thread too..
My buddy Darren owns a good sized excavating, irrigation and landscaping company in Colorado and we talk diesels quite a bit. He has a good sized fleet of small and large diesel engines and a couple of them have over 20k hours with no rebuilds.
The last time I spoke with him about engine longevity he had one Yanmar block and one Mitsubishi block with over 20k hours that have never been rebuilt. He bought both of these machines used with about 5k hours on them back in the late 90's.
Most of his smaller engines are either Yanmar or Kubota but he does have a few Mitsubishi's too and one or two Shibaura (also Japanese; read Perkins / Volvo engines are Shibaura). His engines on this equipment run all day and barely ever shut off. They idle for long, long, long hours especially in the winter months.
Now granted these are not in a marine application
but in well over 500,000 hours of combined run time on his fleet he has yet to rebuild an single small diesel engine. All his machines run Shell Rotella and it gets changed regularly. Of course he buys his oil in 55 gal drums and I buy it by the gallon...
If mid to heavy equipment running Yanmar, Mitsubishi, Shibaura and Kubota blocks can rack up 10k to 20k hours, while doing hundreds and hundreds of hours of idling per year, with no rebuilds, then a well maintained marine diesel should be able to do the same, if run properly AFTER you idle it...
When we had the discussion about not letting diesels idle
a few years ago he just laughed about polishing
the cylinder walls. His sarcastic
comment was something like "Sh&t I better let my guys know not to let them idle"
. Course he'd already been doing it for 25 plus years, with no failed engines or rebuilds needed, so he was surprised to find out his engines were going to die and imminent death soon...
About three years ago myself and a Beta dealer here in Maine had a long discussion with Stanley of Beta Marine, at the Maine boat builders show. The conversation was specifically about bore glazing and idling to charge.
Stanley's take was this is a "non-issue" for the Beta engines. He very boldly insisted
they have not seen a single case of bore glazing in a Beta / Kubota block. Not a single one (this was as of three years ago).
This is the US distributor/importer of Beta engines and a guy who has been working with diesel engines his entire life. He is one of the more honest guys in the business and if we had to replace our Westerbeke tomorrow the guy who would get the engine sale.... He also admitted that the majority of their customers idle to charge
. Still not a single case of bore glazing or polishing leading to an engine failure.
Why do I get a chuckle out of this topic..??? If more sailors worried about how long
they run the engine and how hard
they run the engine, before shutting it off, and actually took care of their engines, we'd likely never hear of an engine failure....
Both of these engines have very high light loading hours and neither has ever been rebuilt. They purr like kittens.... This is why a get a chuckle when a sailor with 400 hours on their Kubota is worrying about running it at idle for 40 minutes here and there.....