Cummins Marine Diesel Repower Specialists › Forums › Cummins Marine Engines › 2011 Cabo 40 WOT

  • Creator
    Topic
  • November 28, 2022 at 7:15 pm #139315

    James Roach
    Participant
    Vessel Name: Callie May II
    Engines: Cummins qsc 600
    Location: St Mary’s GA
    Country: US

    Hello 

    I have a 2011 Cabo 40 that just underwent full service including a top end rebuild on the stbd QSC600 and two new turbos.  We have sea trialed the boat 3 times and we are constantly getting just under 3000 rpm at WOT. Fuel burn and load look pretty good etc. wondering if these 600hp 8.3s with Zeus pods should be turning up over 3000. Attached are the screen shots of WOT today. <br /><br />

     

  • Creator
    Topic
Viewing 6 replies - 1 through 6 (of 6 total)
  • Author
    Replies
  • December 4, 2022 at 8:08 am #139518

    James Roach
    Participant
    Vessel Name: Callie May II
    Engines: Cummins qsc 600
    Location: St Mary’s GA
    Country: US

    Great info

    1. Thanks for that information.  The boat is running great so we will probably make the trip savannah to st Mary’s and schedule a haul out to grease the wheels etc. 

    if I interpret what you are saying correctly, it may not be worth spending the money on a prop shop. Perhaps I just need a slightly different prop?

     

     Attached is the vessel view from yesterday. 

    December 3, 2022 at 9:43 am #139489

    George Baird
    Participant
    Vessel Name: Topaz
    Engines: Cummins QSC 8.3 600
    Location: Herrington Harbor South, MD
    Country: USA

    Jim,

    I have a Prestige 560 with same QSC 8.3 600 and Zeus pods. When you haul the boat look on the props. They have markings which identify which prop you have. It will be M with a number. You may have M10 or M11 based on the size and weight of your boat. My boat was also over propped when I got it. I had almost identical WOT rpm. I took the props to a digital tuning shop and had them tuned and they were able to take a little pitch out. Since they are stainless steel they can’t do very much. I got a little more rpm at WOT but they now had even rpm port to starboard. Not a lot of information out there about Zeus pod propellers. I was able to speak to someone at Mercury who was very helpful and gave me pitch numbers for a few of their propellers. I ended up going down a few pitch sizes and now WOT reaches electronic governor at 3065 rpm. Fuel burn is now very close to curve at cruising speeds. I still have my tuned M9 propellers which I plan to sell at some point. You could PM me if you wish. <br /><br />

    George

    November 29, 2022 at 6:56 am #139337

    Steve Lewis
    Participant
    Vessel Name: Just Us
    Engines: Cummins 480CE
    Location: Marblehead, OH
    Country: USA

    Jim,

    I do not believe those prop sets can be modified.  Since the prop sets are stainless steel as opposed to NiBrAl alloy, you need to replace the propset with a different size.  Hopefully you have a highly skilled, ZEUS certified service organization that can help guide you.

    If you plan on keeping this boat for any length of time then it would be prudent to get the engine loading correct in the cruise range so that they will last.  There are other CABO owners on the forum.  Not sure if any of them have ZEUS pods.  There are other ZEUS owners on the forum so maybe they can share first hand experience with changing prop sets and getting them ordered properly.

    November 29, 2022 at 5:25 am #139334

    James Roach
    Participant
    Vessel Name: Callie May II
    Engines: Cummins qsc 600
    Location: St Mary’s GA
    Country: US

    We are headed from Savannah to st Mary’s in the next few weeks and the boat will be due for a haul. Do you think the props just need a tune while she’s out of the water?

    November 29, 2022 at 4:59 am #139330

    James Roach
    Participant
    Vessel Name: Callie May II
    Engines: Cummins qsc 600
    Location: St Mary’s GA
    Country: US

    Thank you for the info!

    as far as the top end on the port- we started having the dipstick blow out first then we were running and there was quite a bit of oil hitting the back wall from the breather tube. My mechanic checked everything out and we found a lot of pressure in the crank case which pointed to the rings since the turbos are new. When he pulled the top end he found that the rings were lined up exactly with each other. No evidence of other failures etc. he said he’s never seen if before. <br /><br />

     

    November 29, 2022 at 4:41 am #139327

    Steve Lewis
    Participant
    Vessel Name: Just Us
    Engines: Cummins 480CE
    Location: Marblehead, OH
    Country: USA

    Over Prop’d

    Jim,

    Welcome to the forum.  I have attached both the Cummins Performance Report for the QSC600 and my write up on propeller tuning.  If you do some searching and reading on the forum about loading of the engine you will see that you should be able to hit the governor easily.  According to the engine report, that is somewhere in the 3065 to 3085 range.  So you are about 100rpm shy of that.  Also, WOT is interesting but cruise rpm is where we run our boats so the fuel burn in the 2200 – 2700 range for your engine are the critical data points.  Ignore load.  Just focus on fuel burn.

    I explain all of this in detail in the write up.  I consolidated a lot of the engine loading info that you will find here on the forum into this document.  Build out your own performance chart and then come back and post the fuel burn at each RPM interval in your cruise range and then we can have a discussion about your prop set.  Being a pod boat, tuning your props to load your engines correctly is more complicated. 

    What precipitated the top end rebuild on your QSC’s?

    1 user thanked author for this post.
    Scotth
  • Author
    Replies
Viewing 6 replies - 1 through 6 (of 6 total)

You must be logged in to reply to this topic.