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Can anyone share your efficiency data on a 4400 Sovran with QSM11 engines? I am looking at purchasing one and this data is very hard to access.
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Thanks for the information. I'll research the "dry exhaust" issue a little more. Won't she cruise at 25-28kts? That was info I was given for the boat/engine package.
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Home Port: North East
Vessel Info: 2005 4400 Sovran
Cummins QSM-11 660HP
Hi,
We run a little slower for fuel economy. The published data indicates optimum cruise at 24.2 knots burning 38.8 GPH. I will try and find the factory 'Performance Report' PM your contact info and I can send it to you when I find it. Enjoy the weekend!
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Thanks for the information! The other powerplant is the Cat C-12 - produces a little more HP but seems to be a little less efficient. Which is the preferred powerplant? Has anyone had issues with either power combo (exhaust or turbo with QSM, or aftercooler with Cat)?
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Home Port: Lake Michigan
Vessel Info: 52 Sovran, Cat 3406
They are both very good engines if maintained properly and run within the design envelope. I believe all C-12's have the upgraded aftercooler design, released during the 3196 production years. Cat will tell you to replace them every 6 years in salt water applications but many owners have them instead cleaned, inspected and pressure tested. Cummins M11 also a good engine, a little less forgiving to over-propping and hard running due to the exhaust manifold issues. They also had some relatively minor issues with things like the front seal and a gear cooler redesign.
I wouldn't be afraid of either one of these engines provided you get a good engine surveyor and have full visibility to maintenance records. If you want more input go to boatdiesel.com, pay the $25 to join and have at it. Tons of information available in the forum archives from very knowledgeable owners and mechanics.