Originally Posted by manyboats
So the idea that an engine turning faster will wear out quickly is in general just plain bunk.
You're incorrect about that. Not bunk
just incorrect. I have direct hands on experience in this area
A industrial quality 1800 RPM diesel generator engine will generally go something between 20 and 30,000 hours, if it is run at a reasonable loading rate, and otherwise maintained properly.
A industrial quality 3600 RPM generator set might go 5,000 hours but thats honestly pretty few and far between.
I see it with my own eyes. Take a yanmar small diesel and spin it 3600 rpm in a light tower, its a 5,000 hour engine at best. Take that same basic engine and spin it at 1800 RPM and its a 20,000 hour engine conservativly.
That said I would argue in a recreational marine application its for the most part irrelevant. Most recreational generators are infrequently used, and run with almost zero preventative maintenance except oil changes. couple that with a corrosive enviroment and you are setting the engine up for a premature failure.
You really want to see an engine last, look into the generators in the oil field. We have units that typically go 7-10 years of continous duty running with the only shut down for maintenance. Why do these units last so long? They turn at 1200 RPM. Some units that pump oil turn at 600 RPM and can last a lot longer than that. Years longer.
Engine life is very much related to engine speed, but in a marine enviroment where few engines actually wear out having died before their time due to a catastrophic failure, does it really matter?