Cruising RPM, Hrs, GPH, and longevity Tug and Cut diesels

[BB marine]

Late on this trread ~ regarding engine loading and life

I was told this by several Volvo car and Mac truck reps regarding the Volvo turbo/supercharged engine. I was curious about the reliability compared to the red/silver blocks. Remember these are 2 liter engines putting out ridiculous horsepower. There is a lot of case pressure. Told the the engines are fine for suburban use but are having issues in mountainous states - blowing seals from lugging them up mountains

Marine engines area always climbing a hill. This is the reason they should be propped correctly. The engine needs to be loaded asper manufactures recommendation. The engine should turn 4150 rpm to be loaded properly at any rpm. Anything below 4000 rpm WOT the engine is climbing a mountain!!! If you run at 2000 rpm all day long but your WOT rpm is 3800 rpm You are climbing the mountain in over drive lugging the engine. The D3 is a good little motor. It is not a heavy duty truck engine. Propped correctly and used at 30 to 40% load propped correctly you will be boating for years!

 

[Diatom]

2011 C26 Yanmar 4BY2 180, 1100 hours.
Modified original 12" tabs with BB-inspired drop fins, major improvement. Automated with Mente.
Cheap adjacent haul-out means bottom frequently cleaned.
WOT a touch over 4000 RPM, never go there.
Fast cruise 3600 RPM, crossing the Georgia Strait, holds 17 knots except where fighting currents (Active Pass, Fraser River).
Slow/typical Gulf Islands cruise 3350 RPM.
Temperature creeping up slowly over past year approaching 199F, something needs a flush.
Yes boat "gets heavier every year".
/tmm