# Engine destroyed by anti-siphon valve



## jimfortuna (Mar 27, 2000)

I recently purchased a 1991 43' moderately heavy sailboat in Annapolis after I received a glowing survey, successful sea trial and reassurances from the owner and broker that everything was in great shape. I signed the papers, then had the fuel polished, and had a diesel mechanic change filters, and do baseline service. When he started the engine, his face went blank. The engine was loping at low speeds, and had had a unsteady sound. He unloaded the fuel injectors by cracking the connection one at a time, and found the #2 cylinder dead. The local Yanmar dealer did a compression check, changed the injectors, and still no #2. He looked into the cylinder with a boroscope, and found "sodium deposits" from seawater in the cylinder. The most likely source was seawater siphoning back into the engine likely because of a bad antisiphon valve. After removing the head, and measuring the cylinders and spotting extensive corrosion, he concluded that the engine needed extensive overhaul, and it may be more cost effective to replace the engine. In any event, the engine will have to come out of the boat. Fortunately, the existing exhaust has 3" pipes, required for the new Yanmar. Ironically, the boat has never left the slip since I owned it, (only a couple of weeks)

I am planning on replacing the Yanmar 4JH2E (1991 54 HP with 3000hr) with a new Yanmar 4JH4TE (75HP and only slightly more expensive). The gearing will be optimized for use with my existing Autoprop.
<O
Does anyone have experience with a bad survey, and engine flaws from the previous owner (who must have known if he did the service he claimed)? Are there any big penalties going to a more powerful engine (turbo with same block size)?


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## TSteele65 (Oct 19, 2006)

Was the engine surveyed by a marine diesel mechanic, or just the general surveyor? The general surveyor will only do a cursory inspection of the engine.


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## camaraderie (May 22, 2002)

Jim...that is a shame. Don't think you can go after the surveyor...but with the testimony of a marine diesel guy, perhaps you could get a small claims court redress with the owner for some of the cost of the damage. The key issue will be "did the prior owner know". You said you went on sea trial and found no issues so it is possible that the owner did not know if the engine performed properly on trial. 
I generally advise against turbo models due to the added complexity and parts. I would think 54hp is plenty even for a moderately heavy 43 footer. Why do you feel you need the additional HP? 
Finally...for others reading....ALWAYS get a separate survey of the diesel engine on a boat and arrange for the mechanic to accompany the boat on sea trial and put the engine through its' paces. Regular surveyor are generally not equipped to evaluate anything other than GROSS engine issues. A few hundred extra for a qualified diesel guy can save thousands of $$'s


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## mentalfee (Jul 11, 2001)

You may want to consider askuing more questions about the change in engines. Turbos tend to need to run at higher RPMs to keep things happy as opposed to a naturally aspirated one. If you need to use the engine for a lot of charging while on the hook this may be something to consider.


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## jimfortuna (Mar 27, 2000)

The surveyor claims 20 yr surveying experience, USCG Master's rating, and is a former Safety Engineer. He said that he saw no need for a compression check since the engine started right away. 

The engine sounded similar my 3 cylinder Universal on my 1996 Catalina 30 when it was running at cruising speed, but it produced more smoke, which I was told would go away after it is run for a while. Back soot developed on flat surfaces around the exhaust exit after the 30 minute sea trial (discovered when I was cleaning the boat in the slip).

Later, when the diesel mechanic started at the engine, a noticible light blue and white smoke was evident.


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## TSOJOURNER (Dec 16, 1999)

im,
Unfortunately, what one should disclose ethicly and what one should disclose legally are two different things. I'm assuming you were at the sea trials and the engine ran fine? Were there other surveys and sea trials from potential buyers before you? If so, the broker and surveyor cumminity in Annapolis is a tight knit community and previous engine problems would probably have been know by your broker and surveyor. All that leads me to believe there were no prior problems and the seller in all probability did not know. Sad story but another good example of why you should have separate engine and rigging surveys.


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## hellosailor (Apr 11, 2006)

It doesn't make sense to me, that the engine would perform fine in sea trials and then suddenly start loping and running poorly after "just" fuel polishing. Which shouldn't affect the engine at all.

Whether the surveyor was right to just listen to the engine, or to do something more invasive (using a borescope, as the Yanmar dealer did) is a good question. Many owners would have no idea about the engine ingesting some sea water, and without a specific engine mechanic's survey, most general surveys will not look any further than "how does the engine sound".

You'd probably have a 50-50 chance of recovering against either one of them, flip of a coin and the written terms of the survey to decide the details.

"He said that he saw no need for a compression check since the engine started right away. " Then again, an engine will start nice and fast when there's a little LESS compression, so the starter can spin it up real fast. And, something like carbon deposits (or calcium) would serve to BOOST the compression...so the surveyor's statement on this would seem totally illogical.


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## sailingdog (Mar 19, 2006)

20 Years of experience doesn't necessarily mean much, since even a bad surveyor can get away with it that long if they're not completely incompetent. The Master's rating and being a safety engineer are nice, but doesn't necessarily mean they know how to survey or evaluate a diesel engine.


jimfortuna said:


> The surveyor claims 20 yr surveying experience, USCG Master's rating, and is a former Safety Engineer. He said that he saw no need for a compression check since the engine started right away.


Just curious, did they use the boat after you did your sea trial?? Could the flooding have happened after your sea trial and survey???


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## brak (Jan 5, 2007)

I would be careful to not overpay for work that may or may not be necessary. If the engine worked in a seatrial - it may very well be repairable.
My boat has the same engine of approximately same vintage (few years younger) and I do get some soot deposits on the transom when running and also some smoke, especially when starting cold. That said, it got me through almost 600 miles of ICW without a hitch. 
Diesel engines are almost always repairable and replacement is almost always significantly more expensive (though of course new engine would be great for the boat).

That said, you probably won't achieve much. For about 10-15K of expense that engine swap would cost, you are not likely to find a lawyer that would take a case, even if there is one. And, of course, since there is a lot of uncertainty and deniability - you are not likely to get anything. Of course, I'd be very pissed in similar circumstances (and I've been in situations where such misrepresenttion occured).


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## cardiacpaul (Jun 20, 2006)

I recently purchased a 1991 43' moderately heavy sailboat in Annapolis after I received a glowing survey, successful sea trial and reassurances from the owner and broker that everything was in great shape. I signed the papers, then had the fuel polished, and had a diesel mechanic change filters, and do baseline service. When he started the engine, his face went blank. 
The engine was loping at low speeds, and had had a unsteady sound. He unloaded the fuel injectors by cracking the connection one at a time, and found the #2 cylinder dead. 
*
did it sound like this during the sea trial.*

The local Yanmar dealer did a compression check, changed the injectors, and still no #2. He looked into the cylinder with a boroscope, and found "sodium deposits" from seawater in the cylinder. The most likely source was seawater siphoning back into the engine likely because of a bad antisiphon valve. After removing the head, and measuring the cylinders and spotting extensive corrosion, he concluded that the engine needed extensive overhaul, 
*
that may not have happened during the short time between seatrial and diesel guy... "extensive" is a relative term, but to me, sounds like a longer period of exposure than what is being said.*

and it may be more cost effective to replace the engine. In any event, the engine will have to come out of the boat. Fortunately, the existing exhaust has 3" pipes, required for the new Yanmar. Ironically, the boat has never left the slip since I owned it, (only a couple of weeks)

*just the oil and carbon buildup of normal operation wouldn't allow such "extensive" damage.*

I am planning on replacing the Yanmar 4JH2E (1991 54 HP with 3000hr) with a new Yanmar 4JH4TE (75HP and only slightly more expensive). The gearing will be optimized for use with my existing Autoprop.

*let me see if I have this straight, you're "optimizing" the engine and tranny to match an existing prop... 9-12k, vs 1500 for a different prop? *

Does anyone have experience with a bad survey, and engine flaws from the previous owner (who must have known if he did the service he claimed)? Are there any big penalties going to a more powerful engine (turbo with same block size)?[/I]

*Usually, there is O&E insurance (omissions and errors) but I'm not sure this would be applicable. I wouldn't have done a compression check either. If the engine sounded like it was having a problem during the seatrial, I'd have heard it. So would the surveyor (assuming... i know, i know) **FOLKS THIS IS WHY YOU GET A DAMN OIL SAMPLE!!!!! **A perfect time for one would have been at the completion of the sea trial. This would have given you an idea about when, where, why and who regarding the condition of the motor *AT THAT MOMENT OF TIME.

*Did the diesel guy start it before the repair? (if he was doing an oil change, he should have.
Did anyone take the boat out after the seatrial?

what to do now. 
a) whoa there big fella.. Get a second opinion as to if the motor can be repaired. And what the failure was, and what it is caused by.
b) Start gathering records, oil changes, maintence, find out who did what, when, ask the mechanics about the motor and boat. 
c) Heres my take on turbos's. They have no place on a sailboat. they run at higher rpms, hotter temps, neither good for the engine room of a sailboat. *


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## Faster (Sep 13, 2005)

FWIW, (and that may not be much), I'd stay away from turbos too.... who needs the potential extra problems, why do you feel you need so much more power?

Shame the way things have gone, but there may be a less expensive way out than full out replacement. I suspect any real cost recovery would be a long shot.


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## Rockter (Sep 11, 2006)

Do not, do not, do not put a turbocharger on a marine diesel, unless you need it for a powerboat or something. Weight is a secondary consideration for a sailboat motor, and you do not need a turbo on there. They rev like crazy and are expensive when they blow.

Moving up from 54 to 75 hp is a heck of an upgrade. What prop? What gearing? Can the prop take it the extra power? Does it mean a big three blade that you have to drag around with you when you sail?


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## jimfortuna (Mar 27, 2000)

*Turbo vs conventional*

Thank you all so far for you input. I am on a time line, and trying to make the right decisions, so your input really is valuable.

To clarify some questions raised, the engine sounded like the 3 cylinder Universal on my 1986 Catalina... thump thump thump... like an old fishing boat (or the diesel from the Humphrey Bogart movie African Queen)

The cylinders are scored, and well outside Yanmar specs max specs. The oil was new, and the likelihood of getting an accurate indication of the engine condition from a lube analysis was quite low.

Please comment on my rational for a 75HP turbo:
I am comparing a Yanmar 4JH4-TE 75 VS 4JH4E 55 HP
Based on the sea trial shaft speed of 2750 RPM, I was close to hull speed. From the factory performance curves, this requires a propeller power of 40 HP and generates a torque of 97 Ft-lb and 2.5gal/hr fuel consumption.
Going to the 75HP engine, the same 40HP prop power requires 2500 RPM crankshaft speed, thus a different gear ratio is needed to get the correct prop rpm. So the engine rpm is lower with the turbo. My crankshaft torque goes to 140 ft-lb, and fuel consumption drops to 1.8 gph, almost a 30% reduction! With this improvement in efficiency, I would expect that there would be less heat generated. The gearing on the new engine is also over sized for the typical load.
The Yanmar 3JH4 is a 75HP engine that runs at a higher speed, and is not one I am considering.

The advantage for extra HP is fuel economy, more low-end torque, lower rpm for normal operation, and the extra HP if needed to fight a heavy headwind, or pull off a soft grounding. I have the power curves and can send them out if anyone wants them, or you can find them on Yanmarmarine.com

Please comment on my logic, Thanks for the help


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## hellosailor (Apr 11, 2006)

"So the engine rpm is lower with the turbo."
Is that lower rpm still in the optimum speed range for the more powerful engine? I would expect it to be running at only 60% power, which is generally not a good point to run diesel engines.


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## cardiacpaul (Jun 20, 2006)

_The oil was new, and the likelihood of getting an accurate indication of the engine condition from a lube analysis was quite low._ 
So, was the oil new before or after the sea trial, before or after the fuel filter change. If before the seatrial, and there was damage, the scoring (chromium, rust, all sorts of bad things) would have shown up after 10-15 minutes of operation. I just have no idea of a succinct timeline here.

Oil was new at the sea trial? did it make the noises at the sea trial? I'm trying to asctertain WHEN the first time this bad stuff happend.

_So the engine rpm is lower with the turbo._

maybe I missed something but with the turbo'd engine, would it be within the operating efficiency range of the turbo engine?

_I would expect that there would be less heat generated. _
actually, no, exhaust temp will be the same OR higher, plus the added cast iron side of the turbo acts as a nice round griddle in your engine room, just heating everything up nice and toasty.

yes, of course you can insulate, then all those hotter exhaust gases just go down stream a bit further.

maybe I need to state this again. 
a turbo'd engine has no place in a sailboat. (unless its VERY large, like those 100 ft beheamoths)

here are just some off the top of my head reasons. (in addition to the above) 
diesels love to, need to be run at operating temps to be efficient, and for long life. Motoring off a ball out of the bay for 15 - 30 minutes ain't gunna cut it. Add a coke producing turbo to the mix and you're asking for trouble in the turbo bearings, oil turning to tar in the area of the separator bearing, sludging up the works.

turbo "lag"- you WILL have a 1-3 second delay in turbo wind up, this could prove dicey when motoring in close quarters.

but hey, this post might be pointless, an its your money, do what you want.


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## timebandit (Sep 18, 2002)

I like turbos.I liked them in cars and I like them on motorcycles.
I don't think they are applicable in a tight engine compartments of most sailboats. I don't believe there is enough airflow in these compartments.
A good turbo system will glow a dull red when operating under a load and the propeller is a constant load.
My two cents


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## Stillraining (Jan 11, 2008)

*Im confused*

first it was no #2 now it's "there all scored"?

1) Scoring alone in a diesel will not produce a zero compresion reading. Only a valve will do that.

2) Turbos are not like blowers they dont produce any boost benifits untill engine is past 60% max rpm. So you do not get better lower tork with one.

3) 80% of all our marine engine problums are realeated to cooling and cooling water problums, adding more heat in your enging compartment from your warm little round frying pan aint helping anything. Yes they do get red hot!!

4) Yes you could benifit from more horspower, but get it differently with a different bigger normally asperated engine. Whats another 1/2 gal per hour. It's a blowboat .

5) Dont be sturbon you asked for advice TAKE IT !! your getting some good advice from some knowlagable people from what I see.

6) Have the rack run on you curent engine to see if I not right on this compression issue befor you get suckkered into a new one.

I have 17 piecies of heavy equipment with a diesel engine in it. Turbos only help in some instances.

Sorry to hear about your predicament. Hind site is always 20/20
always get 3 surveys 
1) Hull 
2) Rigging
3) Mechanical ( Hull & machanic on board at sea trial )


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## haffiman37 (Jun 4, 2004)

I too am personally no fan of turbo powered sailing boats. However there are some cases where it might be the only solution. 
The engine room compartment is to small to fit in a non-turbo of desired HP range.
Weight might be an issue fitting a bigger non-turbo (going from 4 to 6 cyl).
However the turbo does not get glowing red in the dark, the exhaust turbine housing is water cooled! The heat emission to air does not get significant higher from same engine type with turbo, but the air consumption encrease which might call for modified ventilation . If properly arranged ventilation, the running temp in the compartment might be reduced due to encreased consumption of the air and quicker circulation. The main 'problem' might be the turbo itself, but most likely only after 1000hrs+ of running time depending of use.
The specific consumption of the turbo engine is lower than the normal aspirated one, but only in the turbo rpm range: above about 2500rpm.
However do You need more HP ore do You need more prop-shaft torque?
Have a talk with Your prop supplier and check. Perhaps a different gear ratio and new prop will give You what You want.
Unless You have a dream of sailing with a decal at the transom saying 'Turbo Powered', I would have tried something else.


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## sailingdog (Mar 19, 2006)

Why would you want an engine that is badly suited for the marine environment. A turbo is more complex, more maintenance, more prone to failure, generates more heat, resists the kind of abuse a sailboat engine goes through less and so on. Usually, weight isn't all that critical an issue. If you have a 20,000 lb. boat, the difference in weight between a normally aspirated 75 HP diesel and a smaller 75 HP turbo diesel is meaningless. Why not just rebuild or replace the existing engine's block. Then you would not need to worry about modifying the transmission gearing, or the engine mounts.

As for your reasons:

The larger engine isn't going to give you better fuel economy necessarily. Once you're at hull speed, the amount of fuel it takes to go any faster goes up incredibly. Also, as a turbo engine, the engine won't be working very efficiently at the lower RPM ranges, and will suffer from turbo lag, as previously pointed out.

Since the engine will be a turbo, it isn't going to have much more low end torque, since the turbo requires fairly high engine RPMs to really kick in. This has also been pointed out.

The extra horsepower does you absolutely no good if the propshaft and prop can't handle it. Unless you're willing to spend the money on a larger propshaft and propellor, the additional HP isn't going to be all that useful. Most likely, the current prop would just cavitate, rather than generate any significant increase in power.

Proper propellor selection depends on many things-including the HP of the engine. I could go from a 20 HP on my boat to a 50 HP, but if I didn't change the prop, I certainly wouldn't get an increase in fuel economy or useable power-and it probably wouldn't affect my WOT speed significantly.



> The advantage for extra HP is fuel economy, more low-end torque, lower rpm for normal operation, and the extra HP if needed to fight a heavy headwind, or pull off a soft grounding. I have the power curves and can send them out if anyone wants them, or you can find them on Yanmarmarine.com


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## Rockter (Sep 11, 2006)

Yes, it all needs to be matched, or near so. 
If the existing motor moves the ship well, then repair it and move on.
You really do not need a turbo.
If you try to extract that 75 hp, then you are going to be ploughing water and the fuel consumption will increase, not because the motor is les efficient, but because the boat realy drinks fuel at the higher hull speeds.

If you just have top end scoring, then it should not be too expensive. You should be able to get oversizes and re-bore the barrels. Then a valve seat re-grind (or re-cut and grind if they are pitted), a new cylinder head gasket and you shuld be ok.

Yanmar spare parts are not TOO expensive (compared to Volvo that is).

Cost it out, and see.


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## basta (Jul 3, 2021)

jimfortuna said:


> I recently purchased a 1991 43' moderately heavy sailboat in Annapolis after I received a glowing survey, successful sea trial and reassurances from the owner and broker that everything was in great shape. I signed the papers, then had the fuel polished, and had a diesel mechanic change filters, and do baseline service. When he started the engine, his face went blank. The engine was loping at low speeds, and had had a unsteady sound. He unloaded the fuel injectors by cracking the connection one at a time, and found the #2 cylinder dead. The local Yanmar dealer did a compression check, changed the injectors, and still no #2. He looked into the cylinder with a boroscope, and found "sodium deposits" from seawater in the cylinder. The most likely source was seawater siphoning back into the engine likely because of a bad antisiphon valve. After removing the head, and measuring the cylinders and spotting extensive corrosion, he concluded that the engine needed extensive overhaul, and it may be more cost effective to replace the engine. In any event, the engine will have to come out of the boat. Fortunately, the existing exhaust has 3" pipes, required for the new Yanmar. Ironically, the boat has never left the slip since I owned it, (only a couple of weeks)
> 
> I am planning on replacing the Yanmar 4JH2E (1991 54 HP with 3000hr) with a new Yanmar 4JH4TE (75HP and only slightly more expensive). The gearing will be optimized for use with my existing Autoprop.
> <O
> Does anyone have experience with a bad survey, and engine flaws from the previous owner (who must have known if he did the service he claimed)? Are there any big penalties going to a more powerful engine (turbo with same block size)?


It appears he was looking for affirmation and not information, and ghosted on those responding


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## JimsCAL (May 23, 2007)

You do know this thread is over 13 years old right?


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## basta (Jul 3, 2021)

JimsCAL said:


> You do know this thread is over 13 years old right?


Everything is in the past, but one can still learn from a discussion.. one may indeed learn less when the primary bails out w/o some final outcome or resolution. that's what i was commenting on for future readers. Happy 4th!


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