[George Samaha]

So what was it finally?

[George Samaha]

Hi again, to follow-up on my previous post, we had the aftercooler pressure tested at 30psi, and no leak. So there was no saltwater leak. PHEWW.

The core was soldered, we had repaired some broken pipes and put it back the seaboard way with plenty of Metalube only a couple months ago. Now reopening it because I want to replace the old repaired core with a new one just received from sbmar, but was surprised that it was difficult to separate from the casing. Took a lot of WD40 and about 30-50 strong knocks back and forth (some of them ground shaking) on a thick piece of wood to separate. The water side was still very good but the air side had a lot of new aluminum pitting, on the top and more on the bottom side, actually where Metalube was, ALL Metalube in the air side transformed from green grease to a gray paste with what seems to be aluminum sandings. In 2 months, we created more pitting in the aluminum casing than the whole 19 years before. What is happening?

[George Samaha]

Hi, what is this white powder in the aftercooler’s air side? this is the turbo side. The engine side also has more of it. It is very slightly salty, or maybe I am in denial!!. We will pressure test tomorrow but a mouth pressure test gave no leak.

No unusual smoke or water vapor from the exhaust last time we ran.

Say some salt water went in the engine’s air intake, is there anything to do to stop its effect?

[George Samaha]

Jeff, yes, ideally it should be 13.6GPH at 2200RPM according to Tony’s recommendation, but ours can be completely different, it all depends on weight/drag and props, so we need to find a method to measure the actual consumption without having flow meters or smart electronics… And also to be sure the RPMs are accurate while we are testing. It seems the gauges are not that accurate.

[George Samaha]

I may have the least experience here, but I can say that I had mine (which are discolored) checked by a local mechanic, apparently he did not care much about the color, he only checked for “play” of the turbo fan on its axis and said they are still good. We recently cleaned the bottom and did about 33MPH, so I am happy the engines are giving all their power. I LOVE THESE ENGINES. You should see the waves we created behind us 🙂

BTW guys, now that the hull is clean, how can I check for GPH consumption? At 33MPH, the old analogue RPM gauges were showing 2600+RPM. I got a digital tachometer but dont know where to point it at! The belt covers are in a very tight place and seem very difficult to remove. Props are Hy Torq 22R24 L-CUP NI. Other owners of the same boat/engines have pitched them down to 23 and even 22.5 degrees. I prefer to reduce some weight from the boat rather than messing with the props.

[George Samaha]

Thank you Rob.

[George Samaha]

What is this part in the 6CTA above the water pump (under the fuel pump)? It leaks oil on both engines.. Any suggestions how to fix it?

[George Samaha]

OMG! I will sure open them. Any suggestion how we can unlock those rusty screws? good old WD40 or is there anything better in this case?

If I understand right, by making it safer you mean adding a dry riser after the turbo that goes higher than the water lift mufler’s riser. “inherently safe” as Tony calls it?

[George Samaha]

You’re great Rob. Seems like water is going back in the turbo? Is this exhaust doomed to fail?

[George Samaha]

About seawater pressure testing, I am thinking of making a special hose fitting with air pressure gauge to test the whole seawater side pressure in one shot. Like descaling, would disconnect the water pump output (to insert a fitting with air pressure in the hose. max 30psi) and disconnect the wet exhaust input (to connect the fitting with gauge) and do the test… will have to block the hose going to the dripless shaft seals (if any). In case of leaks, listen or drip some water on hose connections to see if/where it bubbles. If still there is a leak, disassemble the parts and test each separately. Bad idea?

[George Samaha]

Thanks again Rob.

[George Samaha]

Thank you Rob for the pointers about the gear cooler. Yes apparently original and no zinc! 17yrs old… It seems like bronze to me, but when you said fitting, and from the pinkish color where the fitting broke, maybe that was a brass fitting someone put there.

Yes removed the aftercooler core and cleaned water and air side. Waiting for metalube to put if back together. The air side was full of thick oil! OMG I did not expect so muchI Guess this is blowby sucked back in (CC and air filters are very close together).

[George Samaha]

While waiting to get the bottom cleaned and do proper RPM and WOT testing, we are checking the saltwater side. Got the STBD aftercooler core out, it was 80% blocked (see attached)! We cleaned it and will put it back the Seaboard way then pressure-test.

But we had a problem, there is a hose barb nozzle in the gear oil cooler that broke off (so unprofessional I know.. or should I say lucky we caught it?) see the second picture. This is a seawater output that goes to the dripless shaft seals. Is there a way we can weld it back or maybe tap for a new nozzle in there? Is this bronze?

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worldcatlemon

[George Samaha]

Thanks for the details, BTW I was always confused about WOT being at neutral or not. Now it is clear, will do as you suggest. Is there a way to measure GPH on these engines? How the manufacturers do it on the newer engines?

[George Samaha]

No, this horse will drink the water 🙂 As you said, since anyway we are going to do it, I will ask for it.

OMG look at us, it’s Christmas and we’re talking engines. Must be some kind of sickness 🙂

Merry Christmas to all those who celebrate Christmas. May you always be blessed.

[George Samaha]

Rob, you are absolutely right in everything you said, normally I would do it that way, but sometimes there are circumstances… Seller is a friend of a friend, boat is very clean for its age and the price is good (not 6 figures). I noticed the turbos from the beginning but somehow felt it was acceptable because I had seen photos similar, and, I was seduced by the low hours..

I did get a dockside inspection and got a mechanic to look at the engines. He said the engines are in a very good shape (he is an expert in marine gas engines though), he did not even mention the discoloration, so I posted the picture here to see if you guys, the experts, will raise any red flags. After sea trials, I kind of gave my word that I am buying. Now only waiting for them to prep the paperwork. So it is difficult for me to go back and say I want to clean it and test again.

But if you guys think I am making a mistake, I will do it.

[George Samaha]

Sure, I’m here for guidance. I am a programmer but know mechanics, new to marine and diesel and injectors and turbos though 🙂 ! was about 10yrs old when I “helped” the mechanic rebuild my father’s car engine (V8 455). At around 20yrs I rebuilt my motorcycle engine just for the fun of it. I was left with a bunch of screws but it ran well afterwards 🙂 Now in my 50’s I will not leave screws out.

Rob, thank you for pitching in. The captain is the person who takes care of the boat for the owner. He is experienced (and even knows where the zincs are located on the engine), he seems the kind of person who is too meticulous. I have a feeling he did not open the (electronic) throttle to the max, it was at about 150 degrees when we got 2200RPM. Later, when my son raised the volume on the radio, he reduced it by 2 notches as if he did not want to harm the speakers. I am in the same area so he offered his services to me if I buy it, and promised that the engines are good and that the boat will do 22 knots when the bottom is cleaned.

I am not sure we can clean the bottom before buying but the price is good even including the 15k roughly estimated repairs. So I am thinking to buy it and then start by cleaning and checking aftercoolers / turbos, then test full throttle with a good tachometer and log GPH (will install sensors if needed), then go from there. Does this sound like a good plan?

[George Samaha]

Thank you for the fast reply Tony. You are the greatest. The boat is very clean so I think I will buy it after factoring in those costs. I fell in love with these engines, mostly from your comments on them, so I will do some grunt work with pleasure and will treat them like babies. 🙂

[George Samaha]

Hi,

Thank you guys for the helpful information you spread out. I am seeing the same thing, 6CTA-8.3-M3, only 600 hours, darkened turbos and coolers on both engines. picture attached. It is a 2001 Sea Ray 400 bridge. It could not do over 19 knots / 2200RPM on sea trials, empty tanks, captain said the hull is very dirty. Actually he accelerated very slowly and took about 30 seconds to get that.

* Does this seem like a new or rebuilt engine?

* Could it be that the turbos are not working?

* What are the symptoms when the turbos are like the pictures of Monk 36’s turbos Tony posted above?

* At bottom center in the picture, is this the diesel cooler suggested to be removed? or is it the transmission cooler?

* If I buy it and want to test no load WOT what is the max RPM I should get?

Thanks,
George

[George Samaha]

Hi Rick, Glenn, thank you both for your suggestions. I will post more info here when available.

[Author]

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