Diesel questions

Discussion in 'Diesel Engines/Drives/Transmissions/Props' started by Phasma, Jul 30, 2018.

  1. Phasma

    Phasma Active Member GOLD Sponsor

    Sep 17, 2016
    West Michigan
    2003 360 Sundancer
    Mercruiser 8.1s Horizon
    We are considering an upgrade of our 2003 360 Sundancer with 8.1s Mercs to something larger. The current idea is we are considering a 460 Sundancer if we can find just the right one for us. My question is about diesel engines. What is an ideal size/horsepower for a 460? Do I want cats or Cummins? What should I know about hours, maintenance, configuration etc? I’m just hoping to not end up with an under powered boat or a maintenance nightmare.

    I have always been a gas guy so I know very little about diesel. Any help is appreciated.
    Last edited: Jul 30, 2018
  2. scooper321

    scooper321 Active Member SILVER Sponsor

    Jul 4, 2015
    Baltimore, MD
    "Lollygagger" 2003 Sundancer 320, Simrad NSS2 Evo9
    Twin 5.7L Horizon Mercruiser (350 MAG MPI) V-drives
    You can’t ask Cat or Cummins. There are options from both. What are the choices in the model year 460s you’re looking at? Read the owners threads about their boats with those same engines. For example, if it’s the QSM11’s, read the 480 DB thread. 480CE’s? Read the 420DB. Etc. Cat 3126 and 3116 were used lots of places.

    For quicker research, use the search function on CSR and search for the engine you’re considering. That is “3126” or “QSM11”. And read. You’ll read all the warts about every engine and you won’t want any of them. Ha ha. Keep in mind that most of what you’re hearIng on line is negative. You don’t hear the positives because those folks aren’t at the computer, they are out boating!
    northshore and Jus the two of us like this.
  3. Jus the two of us

    Jus the two of us Member GOLD Sponsor

    Dec 7, 2015
    United States Lake Cumberland
    1998 Sundancer 450
    3116 Cats
    We have the Cat 3116s, 1000 hrs, Change oil and filters, Racors, and Trany fluid every year and thats it. The service is a little more costly than gas engines because of the oil capacity , There are some service work at different times of the engine hrs, 1000 hrs for valve adjustments things like that. But the reliability, less fuel burn by far out weigh the extra expense. I personally would not have anything but a deisel boat, Unless it was 45' and would run a 100 mph, and haul at least 4 women!!!
  4. yobub

    yobub Active Member GOLD Sponsor

    Jul 29, 2016
    1998 400 Sundancer
    Cat 3116's
    There is a site called boatdiesel.com that is dedicated to diesel marine engines, much like this site is dedicated to Sea Ray's. You will get good advice in this site but will also find a wealth of knowledge on boatdiesel.

    I was new to diesels this year after 30 years with gas engines. I bought at 400 with Cat 3116s. I called Cat and spent about an hour on the phone with one of their people to discuss some if the specifics in my survey findings, and then they came out to the boat and spent another hour walking me through the basic user maintenance. It was time well spent.
  5. Stee6043

    Stee6043 Well-Known Member

    Jun 1, 2015
    West Michigan
    1997 Sundancer 400
    7.4L Gassers
    Be sure to budget for a proper inspection of the motors during the buying process. Getting a diesel inspected by a pro will be quite a bit more costly than having a gas motor checked over. You'll also need a little more time for the process to complete as I suspect oil sampling is a must-have for diesels?
  6. NotHerDecision

    NotHerDecision Well-Known Member PLATINUM Sponsor

    Jun 28, 2016
    Houston, Texas
    2001 Sea Ray 460 Sundancer
    2014 Seadoo 155 LTD
    2105 Seadoo 130 SE
    2013 Mercury Dinghy
    Cummins 6CTA 8.3L

    There is another recent thread where someone asked about 450 vs 460 and frank and I have discussed pretty much what you are asking. Search for that thread.

    If you have any questions you don’t feel like posting feel free to pm me and we can talk on the phone.

  7. pcarp

    pcarp Member

    Aug 26, 2015
    Grand Haven Mi
    Boat less….
    We were in your position a year ago, sold our 340 and moving to a 410. I was scared and intimidated by diesels and all the unknowns. I started asking questions to my neighbors with diesels and service manager about them. I got comfortable after learning about them and bought our 410 with cat 3116’s. I could not be happier, they are awesome! If you zero in on a boat that you like get the serial #’s off the engines and contact the local dealer / service reps. They will likely have service records for you. I found out the history on my cats this way. I had oil analysis completed thru the cat network, took about 5 days and $15 per engine.
    Dont be scared, gather info and make a decision.
    Good Luck!
  8. scooper321

    scooper321 Active Member SILVER Sponsor

    Jul 4, 2015
    Baltimore, MD
    "Lollygagger" 2003 Sundancer 320, Simrad NSS2 Evo9
    Twin 5.7L Horizon Mercruiser (350 MAG MPI) V-drives
    So a local CAT tech actually came out to your boat (after the survey and after you bought it) to teach you the engine and it's maintenance? That's fantastic! Did you just call the local marine Cat location closest to you? What did that cost, if you don't mind me asking?

  9. dtfeld

    dtfeld Water Contrails GOLD Sponsor

    Jun 5, 2016
    Milton, GA
    410 Sundancer 2001
    Cat 3126 V-Drives
    I love the CAT 3126s I have. The learning curve is pretty steep, but in a boat this size, very worth while. I wouldn’t hesitate with either CAT or Cummins. Both great engines, both have the strengths and weaknesses. All need a little extra TLC when you first take possession to get them on your MX schedule.

    You’ll thank your self every time you load up and head out, and especially at the fuel dock!
  10. Strecker25

    Strecker25 Well-Known Member

    Nov 20, 2014
    Rochester, NY
    1998 290 Sundancer
    Twin 5.7EFI/Alphas, Kohler 4kw
    This seems to come up quite a bit, and we happen to be in the same spot right now. I'm looking at 400/410's and also open to 450/460's should one be the right boat. I joined boatdiesel and have been reading a lot. The survey is of most importance obviously, and the issues with the 3116/3126's are well documented (and from what it sounds like maybe a bit overblown) Like someone said earlier, the people with perfect engines don't get on the Internet and sing their praises, but the troubled ones sure do.

    The thought of a catastrophic diesel failure scares me (because of diesel ignorance), but in the 400/410 blowing up a BBC isn't cheap either. The more I read, many of the complaints for a certain block are the result of possibly asking for too much power from the platform. Lots of talk about the 3208 (offered in the earlier 460) at 450hp being close to the upper limit of that block, but folks mention the 3208 at 375hp to be near bulletproof. The other huge issue is over propping, which SR did on many of these boats from the factory.

    I plan on spending lots of time (and money, compared to gassers) in getting the engines checked out should we find a diesel. There is a surveyor out of florida that the guys on Boatdiesel recommend, and I will seriously consider flying him to wherever our next boat is to do the survey. Plane tickets are a lot cheaper than rebuilding :) and peace of mind when I turn the key each time has some value too.
  11. yobub

    yobub Active Member GOLD Sponsor

    Jul 29, 2016
    1998 400 Sundancer
    Cat 3116's
    Yes, I had some engine survey results that the engine surveyor said were fine but the hull surveyor suggested that I talk through the results with Cat.

    I called my local Cat office, explained the situation, and they connected me with their "Marine Account Manager" who was very experienced with the marine engines (but he is not one of their technicians). He spent a lot of time talking though the survey results and also educating me on the engines and associated maintenance. This was after the survey but before I had finalized my acceptance of the boat.

    After I took ownership of the boat, he came out to the boat and spend at least an hour with me down in the engine compartment, showing me all the parts of the engine and the user maintenance (filters, dipsticks, etc.). He didn't charge me for any of this time, but he certainly did a good job of building a relationship so that I would come to them for service.

    I didn't initially call them to get these services for free - I just called explaining the help I was looking for, and that's how my local Cat dealer (Patten Cat - Northern Illinois) offered to handle it. For them it obviously was an investment in goodwill, both in the Cat brand and in their dealership, and for my part, if a company is willing to treat me that way, I want to continue to do business with them. Overall it was a very positive experience.
  12. JVM225

    JVM225 Well-Known Member GOLD Sponsor

    Apr 8, 2008
    Farmingdale, NY
    2002 410 Sundancer, Monaco Edition.
    3126 Cats.
    Wow! I wish we had Cat guys like that around here.
    dtfeld likes this.
  13. hakunamatata

    hakunamatata Member SILVER Sponsor

    Aug 18, 2015
    Southport Marina - Kenosha WI - Lake Michigan
    410 Sundancer
    Caterpillar 3126
    Patten Cat was who did my engine survey and they were fantastic. The technician who came out post survey to do 500 hour maintenance, oil/fuel filter changes, etc., insisted I be out there when he was doing all of this so he could show me how to do everything. It was a bit overwhelming, and this will be my first run through in the fall, but think in time it will become second nature to do.
  14. Maximus

    Maximus Member

    Jul 28, 2014
    1998 400 sedan bridge
    3116 cats don’t need a 1000 hr service it’s at 2000 hrs for valve lash. Most of us will never have to do it. I change oil every 2 years or 100 hrs. The oil samples dictate that.
  15. Boat Guy

    Boat Guy Well-Known Member

    3116 service intervals:

    First 7500 L (2000 US gal) of Fuel or 250 Service Hours

    Engine Valve Lash - Check ................................... 69
    Fuel Injection Timing - Check ............................... 69

    So, at 250H it's supposed to be done. If you have service records confirming, you should be gd until 2000H.
  16. Russ Calasant

    Russ Calasant Active Member

    Dec 9, 2009
    East Greenwich, RI
    2001 480 DB
    CAT 3196
    Responding to the original post, I had a 460 with Cummins 450’s, and although they ran flawlessly and I loved them over my gas experience I always felt that they were a bit underpowered. Maybe underpowered is not the right word but low end torque was missing a bit and was a slow cruise however they seemed bullitproof. I can only relate to the CAT experience, bigger and a different boat so obviously much more torque and great cruise. And my CATs seem heartier although dirtier - chasing little leaks here and there, smoke a little more but that could just be these motors. I am working through all the maintenance. RE the 460 Cummins package could also be a result of the configuration, deeper tunnels, v drive, smaller wheels etc.

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