Calling all 480CE Owners

Discussion in 'Diesel Engines/Drives/Transmissions/Props' started by 480ces, Sep 11, 2014.

  1. 480ces

    480ces Member

    417
    Jul 14, 2011
    Ontario
    390 Motor Yacht
    Cummins - 480CEs
    Hello,

    I'm looking at a 480CE powered 390 Motor Yacht.

    I've read a few horror stories on dropped valves, failed valve seats, totaled motors due to over loading/propping.

    I'm curious how many people here have had their props tuned or changed entirely to reduce engine load?

    The boat I'm looking at doesn't have the capability to report fuel flows so all I have to go on is its history of Cummins service, light loads and elderly owners.

    Obviously it's a big concern and I'm unsure if I should complete the sale.
     
  2. CougarCruiser

    CougarCruiser Member

    220
    Sep 28, 2007
    Seattle, WA
    (sold) 2004 420 Sedan Bridge
    Boatless
    How many hours on the boat? What does the service history show?

    if the boat clears with no blow by, doesn't blow smoke, makes rpm, and has a decent service history, then it's a great motor!
     
  3. 480ces

    480ces Member

    417
    Jul 14, 2011
    Ontario
    390 Motor Yacht
    Cummins - 480CEs
    Just under 295 hours all freshwater, complete service history by Cummins since new. I feel the valves should have been adjusted at some point but other than that the service history seems complete.

    Survey showed blow by similar to a new engine, no smoke and we hit the 2680 RPM governor at WOT on survey.

    I feel the motors are solid, its just their history of dropping valves/valve seats and overpropping by most manufactures that concerns me.
     
  4. CougarCruiser

    CougarCruiser Member

    220
    Sep 28, 2007
    Seattle, WA
    (sold) 2004 420 Sedan Bridge
    Boatless
    That's a lot of motor for the 390, so over propping would be hard. First valve adjustment is 600 hours, but you would want to have it done due to age of boat. Did the sellers ever go through the raw water side? After coolers, heat exchangers, etc?

    no smoke and hitting rpm is fantastic. Don't worry about dropping valves especially if services are up to date and no history of issues. If you evaluate the fuel curve of a 450 diamond mechanical, and then enjoy the boat, you will be fine. It's a solid motor. There is one other issue with the ECM... Make sure you get them upgraded to the latest version.

    Don't fear the motor... It's a good motor. Join boatdiesel.
     
  5. 480ces

    480ces Member

    417
    Jul 14, 2011
    Ontario
    390 Motor Yacht
    Cummins - 480CEs
    The raw water side hasn't been cleaned yet, I expect it's OK since the boat has been freshwater it's whole life.

    The whole raw water side will be part of my winter work on the boat though. I plane to get cummins in to do the valve lash and ECU updated.

    I've been on boat diesel and its a great resource! Tony is going to be getting an order for all the items I'll be needed as soon as I close on the boat and I never would have found SB without boat diesel!
     
  6. Alex F

    Alex F Well-Known Member

    Nov 14, 2006
    East Coast
    2005 420DB with AB 11 DLX Tender, Raymarine Dual E120 MFD/Radar/XMWeather, ST7001 A/P, AIS, SeaLift
    T-Cummins 450Cs Straight-Drives, 9KW Onan Generator, 40HP Yamaha for tender.
    Your concern is valid, but here's my knowledge on this, based on conversation with my Cummins tech.

    The main cause of the issue was due to defective batch of parts that was used for short time frame. Overall relatively small percentage of the engines were affected. If I recall, the issue usually was seeing on the low hours earlier production engines (around 2003-2004 under 300-400hrs). I suggest to contact cummins to verify this data. I'm sure that your local cummins tech will have access to this info and can give you more detailed explanation.

    There were few theories about overloading and lack of valve adjustments that contributed to the issue, but my cummins tech explained that it's not really related. The defective seat just goes (falls off) out of the place when the engine shuts down. The failure takes place as soon as you start the engine with valve crashing. Of course there are few other scenarios, but I was told that this one was a common one.

    Other than that you're looking at bulletproof working horse engines with very good history. As long as you can confirm that the engines you're looking at don't fit the range of having possibly defective valve seats, you'll love the engines. Don't let the horror stories to steer you away from possibly an excellent boat with excellent engines.

    I would do the following:
    1. Verify with cummins (using serial #) that your engines don't fall in the date range and hours when the defective batch was installed.
    2. Make sure your engine turn 2680-2700RPMs during sea trial.
    3. Follow cummins recommendation on valve adjustments, or better yet, just do them right after the purchase to have good baseline.

    Good luck.
     
  7. trit21

    trit21 Active Member

    Dec 16, 2007
    Live, Orlando: Boat, Ft. Pierce
    See signature
    See signature
    I don't have a horse in this race but just wanted to add what I have read on boat diesel over the past 4 years about 480CE failures. Of course, verify information on your own and read on boat diesel which is where most of this information was gained. 480CE engines, as well as all engines, are susceptible to early breakage from overloading. Overloading is when you add a couple of thousand pounds of your gear, full fuel and water to a boat that, when if left the factory, was propped to pull a light load (no gear, 1/4 fuel, 2 people). This will create EGT (exhaust gas temperature) to rise which, I think this is what is happening on the 480CE, will weaken the valve, valve seat, and cause a failure. Many many documented cases of this happening and a lot of them on boat diesel were the SeaRay 390, probably because there are a lot of them out there. I don't know anything about the bad parts are mentioned above but most of the failure I have seen are the on #6 cylinder which is closest to the turbo exhaust. If it was a parts problem with bad parts, the problem would not be isolated to the rear of the engine where all that heat is generated by overloading. Remember, the boat is just not overloaded at WOT but it is overloaded at all RPM burning more fuel that the fuel curves and creating heat. Now, your main questions is what can be done about it? Well prop the down down to avoid excess heat and take Tony's words of advise on propping for a 450 fuel curve. I am sure many of the 480CE have not had problems but as was stated on BD, the common factor when asking these boat owners that have had that failure about WOT, fuel burn, EGT's, is that the boat was over propped and that is what caused the failure. Again, just trying to give you my thoughts on what I have read. I am not trying to tell you not to buy or dangers of the 480CE just information I have. Don't kill me, just trying to help.
     
  8. 480ces

    480ces Member

    417
    Jul 14, 2011
    Ontario
    390 Motor Yacht
    Cummins - 480CEs
    I'm really not sure what to think anymore.

    From what I gather from the factory these boats weren't over propped, in fact they are propped lower than a 450c. I guess if you REALLY loaded the boat with gear, fuel, water, waste you could overload the engines and cause issues. I did see a few 480CE failures in 390MY's, but no more so than any other engine in any other boat. Most frequent 480ce failures seemed to happen in other boats where I do believe they were heavily overloaded.

    At this point I havn't been able to confirm a bad batch of parts, this boat is an 05, which means the engine could be an 04...I am invesigating with Cummins.

    Can anyone else shed any light on this?
     
  9. LG111

    LG111 Active Member

    589
    Jan 4, 2015
    NW
    410
    8.1
    Hi All, pulling this old string back to life. I am looking at a 420 SB 2005 with 480ec’s. Has anyone had issues with these motors this many years later?

    Thanks,
    Mark
     
  10. swaterhouse

    swaterhouse Active Member GOLD Sponsor

    501
    Jan 7, 2015
    Mattapoisett, MA
    2007 Sundancer 44
    Cummins QSC 8.3
    I still hear of people dropping valves in the 480CE, there was someone on here recently with a report as well.

    The common theme is like said in this thread, prop the boat like it has a 450C and it will run well and last.
     
  11. BubbaFrsh

    BubbaFrsh Member GOLD Sponsor

    51
    Aug 22, 2009
    Tampa, Florida
    "SeaExec II"
    2005 420 Sundancer
    480 CE
    I knew ours was overloaded. Since we were the second owners, we didn't know how hard it was run during it's first 85ish hours. I have taken about 2 1/2 or 3 inches out of the props(down to 25"). To start with a new baseline, I replaced both cylinder heads to make sure I eliminated any potential issues. I figured 15k for two new heads was a better plan then spending who knows what to rebuild a dropped valve.
     
  12. becnme

    becnme Active Member SILVER Sponsor

    138
    Oct 31, 2008
    Fort Myers
    07 44 Sedan Bridge
    Cummins QSC 500
    I have personal knowledge of these engines and their failures both on friends boats and a 42 Sundancer that I owned. I purchased a 42DA that had the seat drop at 500 hours when it was 10 years old. I added boost/egt gauges and had temps over 1000 deg on the first run. Since the engines were out of the Cummins prop curve with my usual load I reduced the pitch by 2 inches which produced an easy 2680 RPM with temps under 800! It does not matter what Searay says, most of these boats are over propped in the real world. The real test is how it operates fully loaded the way you will run the boat.
    I recently purchased a 44DB and like you I looked at several 05 and older boats with 480CE's. Every one I went on had dark brown turbos and tubes. This indicates over propping and heat. I had in mind to change both heads upon purchase as mentioned above. I finally settled on looking at 06 and newer boats to get 500 QSC's and remove the valve problem. I purchased an 07 with under 500 hours and am very happy with the decision. The boat runs better than I expected and the QSC's don't smoke and have good power.

    Happy Hunting!
     
  13. fr8dog

    fr8dog Active Member

    299
    May 25, 2012
    Florida
    Currently Boatless
    460DA
    300DA
    370EC
    Boatless
    Check the part numbers for the heads on the boat. If they are the newer part numbers you should be fine.
     
  14. LG111

    LG111 Active Member

    589
    Jan 4, 2015
    NW
    410
    8.1
    Thanks guys for your insights and experience with these motors. I lived a bad story on my previous none searay years ago and very gun shy on problem engines and drives. I’ll keep my eyes wide open as I move forward.

    Thank you
     
  15. Rgdodson54

    Rgdodson54 Member

    32
    Aug 2, 2015
    VA
    2005 motor yacht 390
    6CTA8.3. 480
    I have a ‘05 390MY with 480s. Cummins had 3 generations of heads, mine has the second. According to Cummins the main difference was the valve seat material. I took out the cup when the props were done. With full fuel and water I burn between 26 and 27 GPH at 18 kts. The valves were recently adjusted, none were more than a couple of thousands out, 1350 hours. No leaks or smoke. Lastly the stupid intake heaters have been disconnected.......
     
  16. JM390

    JM390 New Member

    20
    Oct 1, 2019
    2003 Sea Ray 390 Motoryacht
    Cummins 480 CE
    I have been diving in deep on all this because I am in the process of surveying and purchasing a 04 390 MY also. I can tell you I spoke to Cummins directly about the head issue and as mentioned its strictly isolated to a earlier generation head. The mechanic that said the valve seat drops when shut off is correct. Propping is equally important for EGT's but that is the case with any diesel engine period. If you run over 1000-1200 EGT for consistent times things start to get super hot and can melt things if approaching 1350. Soon as I settle in on one I am going to install a EGT to monitor it just as a safety. Its cheap insurance. Most all the boats I looked at with 480 CE where more towards the brown color. Most have smart craft which will tell you the exact rpms and fuel burn to see if its in spec. Here is the information directly from Cummins. Just check the serial number and youll know. 03-04 were already mostly in the clear.
     

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