How Brown is Too Brown

[Curt Prichard]

Hello,

I am new to this wonderful website and am close to making an offer to buy my first diesel powered boat. I currently have two boats on my short list, both are Sea Ray 2005 420 Sedan Bridge. One has the 450C, 833 hours, and the other has the 480C-E with 630 hours.  Both have reportedly spent most of their lives in fresh water. The 450C has been in brackish water for the last 18 months. I am leaning toward the 480C-E but have a concern that the motors may be abused. The starboard motor was overhauled (don’t have the details at this time) and is still under warranty by Cummins. I am concerned about the port motor. What do you think about the discoloration of the turbo and aftercoolers? Is this expected or signs of excessive temps?

All advice is welcome (including general advice comparing 450C vs 480C-E)

Thank you,

Curt

Topic

[Curt Prichard]

Thanks Dave,

I have been going back and forth between the 450C and 480CE. Now I am pretty certain I will settle on the 450C for all of the reasons you have stated as well as the information above.

Thanks.

[Dave Carlson]

I purchased a 2005 42 Sundancer in November of 2015. After having these engines for a year I would never buy these at twice the reduction. Right off the bat you need to prop them to be 450’s. These engines have one off electronics with little support. If you want to upgrade the SmartCrap you have no chance and need to start over with new systems. The OEM Smartcraft does not give you all the info you want even though there is a page for it! I don’t have load,exhaust temp or any trans info to name a few. I too am trying to decide if I should replace the original head on one engine.

I have been told by Tony my exhaust is doomed to fail which is something you should check into on your boat even though it is a sedan bridge it is the same year from the same builder. Been told it could be 6K.

Tell the broker your plans to buy the cheaper boat and see if the other seller wants to let you walk.

Good Luck

[Curt Prichard]

Guys,

Thank you! I really appreciate your time and advice! What a great website… I will be a regular here.

Sincerely,
Curt

[Corey Schmidt]

I agree… if the 480CE engines are propped correctly per the article, there is no reason they should not provide you with a long, dependable life. Remember, it all comes down to FUEL BURN at RPM… follow the 450C prop loading chart (re: fuel consumption) and you’ll be fine. 

Also, another important factor to consider for ANY engine assessment is “MARINE AGE”. Do you have access to maintenance history of the engines? Have the aftercoolers and other raw water components been serviced? The fact that the boats spent most of their lives in FRESH water is a definite plus!

If you have digital instrumentation with the 480CE engines, they too will provide you with a lot of good operating information.

At this point Rob is right, everything will come down to “Trade-offs”

[Rob Schepis]

A $20K delta…that is not something to overlook.  If you want to be 100% proactive, spend some of that savings and replace the head on the port engine, prop her correctly and run her as you state..

[Curt Prichard]

 Rob and Corey,

Thank you for your replies. You have given me exactly what I was looking for. The article you reference is very informative and now I know how I may proceed with regard to the two boats I am contemplating. I am leaning back toward the 450C but also thinking I will have an engine survey done regardless of which boat I choose. Just one last request for an opinion… If I go with the 480CE (asking price is $20K less), and after an engine survey, I will re-prop if necessary and will be boating on a lake where 95% of my cruising will be less than 2200 RPM (mostly 1400-1800): Will I have pretty good odds of not having a valve seat issue on the motor that has not been overhauled or is it likely that the damage is done and now just a matter of time before bad things start to happen? (Update: attached pictures were taken prior to repair work).

[Corey Schmidt]

450C vs 480CE

Rob is 100% correct re: general over propping on the 480CE engines —- lots of “colorful” history, read this article to learn a bit more and post questions if you have any:

Propping the Cummins 6CTA 8.3 480CE vs. 430/450 Diamond Engine

[Rob Schepis]

450C vs 480CE

Some browning of the air side is normal but that dark is more than you want to see, especially into the aftercooler housing to that degree.  And one motor already failed.  Sounds like the not uncommon overpropping of the 480CE resulting in valve damage.

As far as the 450 vs the 480CE:

Forget the power difference.  The 480CE must be propped down to the 450 propping specs for any longevity to be expected.  It’s the same 450 powertrain just pumped up with more fuel/air.

The 480CE was the in-between C engine before the QSC common rail was introduced.  It offers digital display with running parameters such as fuel burn which are all a very handy tool but it comes at the expense and complexity of an ECM and a digital display which can give up the ghost to the boat gremlins resulting in frustration and $$……There are always trade-offs….

 

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