2005 460 - 480CE Valve Drop

[Alex F]

As you can see, when Cummins squeezed 30 extra HP from the engine, SR engineers got too excited and started putting larger props. At least this was the case for 420DBs, which I know for a fact. But, it seems as different DA models experienced similar trend. It obviously was a race for better performance. Better speed = excellent selling point. It was all great until the owners started experiencing failures and learned that it was due to the fact that the OEM setup was too aggressive and overloaded the engines. The reality shows that one has to take a step back and rethink the approach. For this reason Cummins came out with a bulletin recommending to tune the props to be 75-100RPMs over official rated (2600) RPMs.

I'm sorry to hear that you had to go through this experience. It's interesting to know what was on the pre-purchase survey report and observation during the seatrial? Did the boat meet recommended RPMs? I'm going to throw a guess that your WOT was under 2600 and that was on lightly loaded boat. I also wonder if your surveyor gave you any recommendation on performing any tuning for the health of the engines, knowing the dropped valve issue with 480CEs.

 

[ttmott]

As you can see, when Cummins squeezed 30 extra HP from the engine, SR engineers got too excited and started putting larger props. At least this was the case for 420DBs, which I know for a fact. But, it seems as different DA models experienced similar trend. It obviously was a race for better performance. Better speed = excellent selling point. It was all great until the owners started experiencing failures and learned that it was due to the fact that the OEM setup was too aggressive and overloaded the engines. The reality shows that one has to take a step back and rethink the approach. For this reason Cummins came out with a bulletin recommending to tune the props to be 75-100RPMs over official rated (2600) RPMs.

I'm sorry to hear that you had to go through this experience. It's interesting to know what was on the pre-purchase survey report and observation during the seatrial? Did the boat meet recommended RPMs? I'm going to throw a guess that your WOT was under 2600 and that was on lightly loaded boat. I also wonder if your surveyor gave you any recommendation on performing any tuning for the health of the engines, knowing the dropped valve issue with 480CEs.

Surveying is a conflicted business; on one hand they need to represent who is paying the bill and on the other they need to stay in the brokers back pocket as 90% or their business comes from the broker's recommendation and the brokers want to move boats. So I think they draw a careful line between technical findings and their technical knowledge.

 

[Alex F]

Surveying is a conflicted business; on one hand they need to represent who is paying the bill and on the other they need to stay in the brokers back pocket as 90% or their business comes from the broker's recommendation and the brokers want to move boats. So I think they draw a careful line between technical findings and their technical knowledge.

You make an interesting point, but surveyors better draw that line very careful, otherwise they'll be shooting themselves in the foot. Any customer getting in a situation, when they go through a purchase process and shortly after a vessel suffers a catastrophically failure, it directly reflects surveyor's knowledge and due diligence. Any buyer is expecting a surveyor to provide professional observation and guidance, protecting a buyer from experiencing such failure as OP shared in this thread. In this case, if the boat didn't reach above 2550RPMS and a survey didn't provide recommendation to tuning the props to avoid a well known issue on 480CEs, IMO, they failed to provide expected service and need to take some responsibility.

 

[craigswardmtb]

In my last two boat purchase i made it a point to ask for the brokers top 2 recommendations for both engine and vessel surveyors. I then do my research and pick my own that are not on their list. Seems like a reasonable way to avoid conflicting interests. I'm generally a trusting person, but not when it comes to any services provided around a boat.

 

[ttmott]

It seems to me that if you can find a good recommended surveyor that primarily works with insurance companies you might be a bit better off

 

[dpvandy01]

Thanks for all the information! Very much appreciated. After talking with Cummins I guess the new (not repaired) head they are going to put on is the fix for the dropped valve issue. So now the question is do I keep the 27” pitch with the new head or still pitch it down? Again thanks for the feedback. We keep the boat in Grand Haven at Keenan Marina.

Is the head replacement on your dime or Cummins? And if you don't mind me asking, what was the total cost for the replacement?

 

[Blown284]

We are back up and running. Ended up buying new props for the boat, same diameter just less pitch. The fuel burns are down significantly but we are also considerably slower, about 22MPH at 2,300rpm. We are still working with insurance company but I’m not real optimistic they are going to pay. The bill from Cummins was just under 12k. “Buy a boat, it’s fun” they say!!

What prop size did you end up with and is the bottom clean? 22mph @ 2300 rpm does sound a little bit slow but maybe you have a hard top, hydraulic platform and running into a 20mph wind with 6 knot currents?