Qsm 11 am I propped ok

[Derek chandler]

Did a repower last summer qsm11 670 .had a Doosan before anyway here is what I have gear is a twin disc 5082 2.05- 2.25 inch shaft prop hytorq 32/30 four blade sea trial 2370 wot 96 percent load  1750 rpm load 51 percent fuel burn 13.9. 1850 load 55 percent fuel burn 15.6 . 1940 rpms load 60 percent fuel burn 17.8  . I want to know if I should add a little cup or leave it alone to me it seems a little light . My egt never went over 1000 degrees . Thanks again for a great resource 

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[Derek chandler]

I have done this no matter what direction I will get 2370 fuel burn is 30.1  to 29.6 speed is 24 knots in 42 provincial  so tony I can safely run say 2100 if I am in a hurry . I took a long time choosing my gear to get where you say and want a long trouble free exhaust and turbo . I do go 50 to 75 fish quite often so getting my best safe cruise is what I am looking for 

[Tony Athens]

You look real good to me, but here’s something else to ponder..

1) what is the magic vessel speed you (& your vessel) like to travel at ?

2) Do you also have a “magic” GPH (not to exceed) that make senses when traveling from point A to Point B  as to Miles Per Gallon ?

3)  I’ll also throw this in–It’s basically impossible to under prop any high performance marine diesel of any color, you can only over prop it..  But you also have to mix in your need for  speed and if you are happy with your cruise speed, getting that speed at a higher engine RPM is always better for the engine, especially with the dry QSM11.. ……………… Why you ask?  Because you are pumping more oil, more coolant, more seawater & more  air, and also have that all important reserve at the top of the curve should you need it. Plus, any planning hull will get over the hump was easily and faster when the engine can easily exceed its MINIMUM rated RPM

BTW, what was the RPM & GPH at WOT?  Vessel speed go 2-3 directions?  Go there for 5-10 seconds or so and write it down in your log books for future reference.. That’s a very important base line to establish when things are new.

Tony

 

[Derek chandler]

Ok thank you so what you are saying is I am good on what tony recommends for good manifold life that’s what I want so I guess I am going to save my money and stick with my current prop

[Rob Schepis]

 Derek,

Your WOT rpm and load look good and I made a quick plot of the data you provided on the qsm11 prop curve so you could see what is happening at cruise rpm’s because that is what really matters.  You seem to be right where you want to be.  I would not add anymore “wheel” and I don’t think you’re leaving any horsepower on the table..  Here’s my plot and a helpful link.  You can take the gal/hr readings at the specific rpms listed on the right on the first link for a more finite comparison.

QSM 11 Prop Curve – For Exhaust Manifold Health

 

 

[Derek chandler]

I I am just looking to know as I am going to get a new prop and would like to start off close to where I am

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