Cummins Marine Diesel Repower Specialists › Forums › General Discussion › Proper Loading of a QSM11-715 › Overloaded…
Corey Schmidt
Engines: Cummins
Location: Oxnard, CA
Country: USA
Overloaded…
It still amazes me that boat builders pay NO ATTENTION to the prop demand curves for these engines when choosing and installing them… boats only get heavier over time, not lighter. Both of those seatrial graphs prove that the engines were grossly overloaded to begin with. Absolutely amazes me…
If I had a choice, knowing what I know… personally, I would choose the QSC engines burning roughly the same amount of fuel at higher RPM… less potential exhaust issues and more oil/coolant flowing around the engine. Granted that personal assessment is holding a lot of external factors at control. However, both engine models, when setup CORRECTLY, will prove to be work horses and provide years of service. It’s usually not the engines fault when failure occurs, its the “nut behind the wheel”.
Bottom line = pitch down to where your M11s burn less than 19-20 GPH at cruise and you will never have to think about the “greener” grass with another engine such as the QSC ever again.