[csjodon]

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.

[TIARA44]

Hi,

We have a 2005 44' with QSM-11's rated @ 660HP.  We usually cruise it around 1600 RPM burn 32 GPH and see about 18-21 knots depending on tide, fuel load, trims tabs, etc.  I did take a little off my props as the 'dry exhaust' on the QSM is not the best design, I have already had to replace exhaust manifold gaskets at 850 hours.  Next time I pull the props I will take off a little more pitch off to get GPH numbers lower.  Tony Athens has a wealth of information about the QSM's on his website [Only registered and activated users can see links Click here to register]   This is our 10th season with the 44, enjoy your boat!!

[csjodon]

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.

[TIARA44]

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!

[Dallas]

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.

Here is the info from the PO of our boat who had the props done at Michigan Wheel- see attachment

[csjodon]

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)?

[jclark003]

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.