GPH 430 Ocean Alexander w/Twin 5.9 Cummins

[kip]

Hi Folks,

I have been using this forum as a guest for about a year and have found tremendous educational tools here. Have recently 'retired' to the Chesapeake Bay and am looking at Trawlers. Just had an opportunity to board a 2000 Ocean Alexander 430 Mark I. Was quite impressed with the design, layout and overall boat quality. Am quite reluctant to proceed with this boat as it has twin Cummins 5.9 6BTA engines, but have read here and elsewhere that these engines are good and can be run a low rpm's and will yield good gph at low knot speeds. Anyone out there who can advise as to the truthfullness to this? I like this boat very much. Price is pretty attractive and I think this may be the trawler for me, however, am rather shy as to committing to twins, especially of this size, as I am trying for 2-3 gph burn rate at 6-8 knots. Do you think these engines can move this vessel along at these speeds with this kind of burn rate, and if so, will the engines be able to sustain it for long periods without undue engine wear? Have read that cranking them up to 2400-2500 rps every couple hours could be a solution? Anyone out there have this configuration in a OA?

I am novice to all this, but have 40+ years as a farmer/rancher and am somewhat familiar with dry land diesels. Have had Cats, JD"S etc.

Thanks in advance for your thoughts

 

[sunchaser]

Kip

At 7 (not 8) knots these engines should give an honest 4 gph combined. Have the boat and motors been properly taken care of? I note the pictures in yachtworld and the exhaust elbows look pretty rough (if the same vessel) so have a marine engine pro look this area over very carefully.

 

[RT Firefly]

Greetings,
Welcome aboard.

 

[bnoft]

I have seen the same listing and did a little research, nice looking boat. But the exhaust elbow design appears to be flawed with the water injection port on the engine side of the mixing elbow. This will allow salt water to flow "backwards" into the dry stack and the turbo (gravity), not a good situation. There is a discussion on boat diesel.com about this very boat, Tony Athens is my source. I also asked my son (HMY broker) and he talked to a guy in a very respected and high quality yard in Miami who upon seeing the picture from yachtworld said the same thing. That exhaust elbow needs to be totally reworked and the turbo may need to be replaced. Worse, the engine may have had some salt water incursion from the turbo.Now you're into real $$$.

 

[Wadosan]

...will the engines be able to sustain it for long periods without undue engine wear? Have read that cranking them up to 2400-2500 rps every couple hours could be a solution?

I have been told, by a professional who knows diesels and train in the maintenance and repair of such, that running the engines up to about 100% load every 15 minutes each hour is indeed recommended to prevent the carbon build-up on higher horsepower engines.

Cummins are excellent engines...in trucks both over-the-road and light duty trucks. I see them in boats but are not talked about much in the forums that I can see. I believe almost all of the serious passagemakers run John deeres (lugger), and older boats the Fords, maybe Perkins, Gardners, etc. I would think though that with proper care (as with any engine) would probably outlast the boat or at least the owner. It seems the longevity of the engine is related to it's power density per cubic inch. Just my observation. No actual experience.

 

[sunchaser]

running the engines up to about 100% load every 15 minutes each hour is indeed recommended to prevent the carbon build-up on higher horsepower engines.

Neither CAT, Cummins, JD, Volvo nor Tony Athens on boat diesel would agree with this. 100% load at full throttle 25% of the time is only reserved for commercial duty - at best! Few if any engines in our normally over propped toy boats would survive 100% load for 15 minutes every hour. Look up JD's well stated M1, M2, M3 and M4 ratings or Cummins similarly stated engine rating specs.

Dock talk can be dangerous.

 

[JD]

running the engines up to about 100% load every 15 minutes each hour is indeed recommended to prevent the carbon build-up on higher horsepower engines.QUOTE]

Neither CAT, Cummins, JD, Volvo nor Tony Athens on boat diesel would agree with this. 100% load at full throttle 25% of the time is only reserved for commercial duty - at best! Few if any engines in our normally over propped toy boats would survive 100% load for 15 minutes every hour. Look up JD's well stated M1, M2, M3 and M4 ratings or Cummins similarly stated engine rating specs.

Dock talk can be dangerous.

I think this is a matter of sentence construction. I think he means run them up to full load every fifteen minutes for just a minute or two not for fifteen minutes continuous every hour. Or at least I hope that is what he means.

In which case he would be OK but what a PIA to do. I run mine up for a few minutes every time I'm out but just at random and usually on the way back in for about two or three minutes at the end of a days run.

 

[RickB]

Has anyone considered that the visible part of the exhaust elbow is the outside of an annular water cooled section and the injection point is actually a few inches downsteam of the point where the rubber exhaust hose is attached?

 

[GFC]

Sunchaser...I'm curious about your comment that the engines would not survive WOT for 15 minutes every hour.

When I did my sea trial I was told by a guy from the main CAT marine place that we should run the engines up to WOT for 20 minutes for two reasons. First was to check to see if the boat was over propped or under propped. if it was over propped the engines would reach the WOT speed but not the WOT rpm's. If it was underpropped it would reach the WOT rpm's but not the WOT speed. (At WOT the rpm's should be 2130 and the speed at 30.1-30.3kts).

The second reason was to make sure the engines/turbines/trannies didn't overheat.

The salesman balked at this but the CAT mechanic I had there to do the engine survey said the engines would run all day at WOT if you could afford the fuel burn rate.

Long story short, we insisted this be part of the sea trial and the salesman backed down. We ran at WOT for 20 minutes, the rpm's were steady at 2130 and the speed varied between 30.1kts-30.3kts and the temp never climbed above 175.

Hence my curiosity about your statement that the engines wouldn't survive.

 

[JD]

Has anyone considered that the visible part of the exhaust elbow is the outside of an annular water cooled section and the injection point is actually a few inches downsteam of the point where the rubber exhaust hose is attached?

As in "not in the picture" down stream?

 

[JD]

Sunchaser...I'm curious about your comment that the engines would not survive WOT for 15 minutes every hour.

When I did my sea trial I was told by a guy from the main CAT marine place that we should run the engines up to WOT for 20 minutes for two reasons. First was to check to see if the boat was over propped or under propped. if it was over propped the engines would reach the WOT speed but not the WOT rpm's. If it was underpropped it would reach the WOT rpm's but not the WOT speed. (At WOT the rpm's should be 2130 and the speed at 30.1-30.3kts).

The second reason was to make sure the engines/turbines/trannies didn't overheat.

The salesman balked at this but the CAT mechanic I had there to do the engine survey said the engines would run all day at WOT if you could afford the fuel burn rate.

Long story short, we insisted this be part of the sea trial and the salesman backed down. We ran at WOT for 20 minutes, the rpm's were steady at 2130 and the speed varied between 30.1kts-30.3kts and the temp never climbed above 175.

Hence my curiosity about your statement that the engines wouldn't survive.

Big difference doing it once for a sea trial and doing it 15 minutes of every hour in operation.

 

[sunchaser]

Has anyone considered that the visible part of the exhaust elbow is the outside of an annular water cooled section and the injection point is actually a few inches downsteam of the point where the rubber exhaust hose is attached?

I agree with you Rick with your description similar to how many OAs, old and new, I've seen are indeed plumbed. The heat wrapping around the elbow looks torn up as if some recent maintenance was or should be done. The rust under the elbow seems worth inspection too.

 

[sunchaser]

Sunchaser...We ran at WOT for 20 minutes, the rpm's were steady at 2130 and the speed varied between 30.1kts-30.3kts and the temp never climbed above 175. QUOTE]

JD

GFC -- Good points. It sounds like your boat is propped right and the engines are in good shape. Now go to the Cat book or website and it will give a duty rating and 100% power allowable run time at that or more likely 80% setting. 80 to 100% 20 minutes once every week is a lot different than 15 minutes every hour.

What if your planing designed vessel was intentionally over propped to run at trawler speeds only to "save fuel" as so many think will occur, would you run it at 80 or 100% ever? Or what if your vessel during seatrial had over heated while never achieving full rated RPM, would you have bought it?

What Cat engines do you have?

 

[Wadosan]

I think this is a matter of sentence construction. I think he means run them up to full load every fifteen minutes for just a minute or two not for fifteen minutes continuous every hour. Or at least I hope that is what he means.

I did mean full load but realize most can't attain 100% so said "about 100%". But I was wrong anyway. I looked around for my email that had that info and this is what he said: "Avoid chronically underloading your engine. If you must do so, run it at up to 80 percent of its full load for 15 minutes out of every four hours to stem the sludge, varnish, and carbon tide." Vastly different from what I wrote so apologize for the error. I'll make sure I get my crap straight before I post next time.

 

[sunchaser]

I get my crap straight before I post next time.

If we all waited until our crap was straight, there would be very few TF posts and little banter. Keep on slingin -----

 

[Wadosan]

If we all waited until our crap was straight, there would be very few TF posts and little banter. Keep on slingin -----

Thanks.

 

[Underway]

I have seen the same listing and did a little research, nice looking boat. But the exhaust elbow design appears to be flawed with the water injection port on the engine side of the mixing elbow. This will allow salt water to flow "backwards" into the dry stack and the turbo (gravity), not a good situation. There is a discussion on boat diesel.com about this very boat, Tony Athens is my source. I also asked my son (HMY broker) and he talked to a guy in a very respected and high quality yard in Miami who upon seeing the picture from yachtworld said the same thing. That exhaust elbow needs to be totally reworked and the turbo may need to be replaced. Worse, the engine may have had some salt water incursion from the turbo.Now you're into real $$$.

There's another 43 OA on Yacht World with Cummins Diamond engines. The photo of the exhaust elbow on that engine shows the injection port in a similar location. Wonder if there's significance to the upward loop in the injection hose...

 

[twistedtree]

I'd suggest finding the manual for the exact engine in the OA, see what it says about partial loading (running slow), and carefully read the details about the engines rating and allowable usage.

I've got a slightly different model Cummins in my current boat, but the book clearly spells it all out.

And keep in mind that running the engine up at some interval may be a good idea in theory, but is often impossible to do in practice based on where you are cruising.

 

[FF]

"If you must do so, run it at up to 80 percent of its full load for 15 minutes out of every four hours to stem the sludge, varnish, and carbon tide."

This might help keeping the rings from sticking and the other usual under loading problems ,
BUT all the crap, blowby and sludge is IN THE OIL!

So a more frequent oil and filter change (at least Double) will be a big help.

The additives (15% of the oil volume) have to work overtime to keep the gunk in suspension and fight the acids.

A bypass filter , even the toilet paper type might help , tho I would install a Lubrifiner or similar real bypass system.

Have never heard "You killed that engine with too fresh , too clean oil."

 

[sunchaser]

"
Have never heard "You killed that engine with too fresh , too clean oil."

Or as some experts say, "Have never heard of killing and engine that runs lightly loaded most of the time."

Such as all the old high hour Lehmans, Cats, Cummins or Perkins that are well represented on TF

 

[Codger2]

So a more frequent oil and filter change (at least Double) will be a big help.

Have never heard "You killed that engine with too fresh , too clean oil."

I'm guilty of changing the oil too often, however, I believe it's the "kindness & cheapest" thing I can do for the Cummins.

 

[RickB]

Or as some experts say, "Have never heard of killing and engine that runs lightly loaded most of the time."

Such as all the old high hour Lehmans, Cats, Cummins or Perkins that are well represented on TF

That's because no one seems to think about the fact that propulsion engines don't suffer the same indignities from low load operations that generator engines do. Everyone likes to talk about low loading issues but then they post links or quotes from articles that describe a generator application.

A generator runs at full rated speed regardless of the load, that is the difference. A properly propped propulsion engine operates (more or less) proportional to load, low rpm, low load, high rpm, high load. The engine is generally quite happy to live like that. It is only the owners who freak out.

 

[Taras]

I think the first question that I would be asking is if the boat is a "full displacement" hull or a "planing" hull.

 

[magicbus]

I think the first question that I would be asking is if the boat is a "full displacement" hull or a "planing" hull.

I was wondering this myself. I have only single 5.9 and can't figure out why you would need two of them unless you plan to plane.

Dave