Yanmar Smoking and Making Oil

[Boracay]

The decision as to whether to repower depends on many factors, particularly the design, construction and fit out of the boat, the intended use and the viability of alternatives. Can you give us some more information?

Not from cruising but when I was younger and less sensible I had a fancy to learn to fly a helicopter. I was learning on an old Bell 47G with an old Franklin engine. Noisy and heavy but reliable.

Knowing that my instructor had worked as a pilot mustering cattle in the Northern Territory where the Bell 47Gs had been re-engined with turbo power I asked how he would know if the engine had failed.

He said : "You think you've gone deaf...".

[hellosailor]

Manuel-
"there are no oversize pistons-rings for turbo engines, "
This seems unclear. If Yanmar says there are oversized PISTONS available, or to be used, maybe the dealer is getting "piston rings" confused thinking that you somehow want to use the original pistons with larger rings? Which wouldn't be feasible.
I would suggest checking the parts availablity and rebuild procedure directly with Yanmar, because I've heard a lot of "Oh, that's just not possible" from a lot of highly qualified and certified people who either just didn't understand the question, or didn't know the answer. Or, didn't want to do the job the way it should be done.
There's nothing wrong with using liners when the job is done properly, that's the normal way to rebuild a lot of engine. But sometimes, parts that DO exist and ARE available, just don't get into US catalogues when they are shown very clearly in the Japanese (etc) ones.

[blueknight]

bstreep: considering repower, but will have to figure out import costs since I live in Peru.
Repairing locally is a good possibility. Good mechanics and reboring shops with the right tools to follow manual specs.
sww914: I tried new thread, but only got bstreep´s input, while on this thread I got yours, boracay´s and hellosailor pretty fast, besides we are talking about smoking yanmars and overhauling.
Boracay: Boat is a 50 feet Beneteau sailboat, manufactured in Dec 2000, ex charter boat, out of Moorings, St Maarten, FWI.
Had it for 2 years. Sailed it from St Maarten to Peru thru Galapagos. I put new sails, new paint, new electronics, looks like new now, fantastic ocean cruiser.
Will like to keep this hull, very comfortable for offshore cruising and weekend sailing with family and friends.
hellosailor:I found some quality japanese liners I could use with std pistons, rings, bearings, etc. because they do not sell oversize pistons and rings for turbo engines like mine. They do sell oversize pistons and rings for non-turbo engines only.
That´s why I was wondering if anyone could tell me if I could overhaul a turbo engine using liners because the yanmar service manual that i have for the 4JH3-HTE and DTE engines says these engines are overhauled reboring the block and not with liners.
best regards to all,

Manuel

[Tranquilo]

So many Yanmar problems I never have with my trusty old Perkins 4-108.

[Boracay]

blueknight
As you've probably realised by now repowering with another engine is going to be difficult. Your rebuilding facilities, however, look to be excellent.

Can you find a rebuilder with experience in turbo diesels?

Reason I ask is that when I repowered Boracay the turbo Yanmars were going for the same price as the normally aspirated version. My John Deere 4045D (non turbo) was only a few dollars more and had double the cubic capacity. It would probably be too bulky and heavy for your boat.

In Oz its not really worth while to rebuild engines. The end cost is similar to brand new, and its still an old engine.

You may be able to find someone who is used to rebuilding tricky turbo diesels. If you do please let us know how it turns out.

[blueknight]

Boracay: We do have less expensive labor and reboring shop costs and decent enough mechanical expertise, so the repairing process should work, at least for now. It is also true that most local expertise is in non turbos, but there is turbo knowledge. Hopefully enough for my tricky turbo engine.

I will nontheless start quoting for new Yanmar or Perkins engines (This thread really scared me on the Yanmar brand) I will rather quote non turbo engines.
In the other hand, overhauling at 10,000 hrs speaks really good for Yanmar.

hellosailor: you encourage me to go with the liner solution on my cylinder block but I am still worried about what I read on the service manual: 4JH3 engines are rebored and not overhauled with cylinder liners because of the way the iron cast block is made, the metal and its cooling capabilities (i guess) is prepared for reboring not to be cut for instaling liners ?

regards,

[boden36]

If you give the relevant dimensions to a good automotive parts specialist you may be able to get a set of rings meant for something else that will fit, even if you have to have your ring grooves re machined slightly.
Regards,
Richard.

[Bill Burgette]

You can probably get oversize pistons made for you. I have sent a piston for a Maytag gas powered washing machine and a piston for a 400 HP forged Mitsubishi engine to a company called Arias. They have always made custom pistons. The Mitsubishi piston was $285.00 but it arrived balanced and complete. They take your piston, forging blanks and their equipment to exactly copy what you have.

I know it's kinda pricey but from what I've heard about Yanni prices it may not be too much more so. Just an idea if you don't want to sleeve.

[smallyachts]

Perhaps the reason Yanmar does not offer oversize pistons for the turbo units is because of final wall thickness/strength needed for the increased combustion pressures of the turbo engines in the cylinder walls.

Tech manuals are often full of misprints and sometimes just bad information. I would stick with information from experienced Yanmar turbo diesel rebuilders.

I have both Yanmar and Perkins. I like the Yanmar because it rarely leaks, however Yanmar is sometimes hard to get parts for.

I like the Perkins because it rarely gives me problems, when it does parts are pretty easy to come up with, but as with most Perkins, it leaks oil.

[blueknight]

thanks for all your comments, going to the reboring shop now to make shure wall thickness is not an issue and checking on those japanese liners that will fit
will keep you posted
regards,
Manuel

[delmarrey]

To bore a casting cylinder enough to intall a liner/sleeve would compromise the castings strength. The compression ratio on diesels are not one I would be extracting any metal, especially after years of hot & cold, hot & cold, hot & cold.

The large diesels come with liners installed from the manufacture and are EZ to replace.

Personally, I would go with an all new motor. That would eliminate any future problems for a long while (alternator, starter, oil pump, heat exchanger, exhaust, flex plate, transmission, fuel timing pump and gears, motor mounts, gauges, wiring & the availability of parts)! Add'm all up and see what it costs.
There are a lot of parts to a marine motor and they seem to go bad one at a time just as the other one has been replaced.

[sailstoo]

Originally Posted by Tranquilo

So many Yanmar problems I never have with my trusty old Perkins 4-108.

The reason there are so many Yanmar problems is brcasuse there are so many Yanmars. Converse is true with Perkins. Think about it.

[nico105]

Head Gasket for the gray smoke...or enough air in the system from another rout, but not enough shut her down would
produce a sheen on the water and give you endless gray smoke

[Jim Cate]

Originally Posted by sailstoo

The reason there are so many Yanmar problems is brcasuse there are so many Yanmars. Converse is true with Perkins. Think about it.

I think that the real issue here is the high percentage of the folks who do have trouble, first with their Yanmar, and then with the Yanmar customer support system. Stories like Terry's are just too common in the cruising fleet... we've encountered a shocking number of them.

Terry's problems happened in his home stomping grounds. Consider the plight of folks with Yanmar problems far from home. I doubt if any of us are really competent to judge the relative technical merits of one diesel over another, but even a simple cruiser can identify poor service, non availability of parts and a "screw-you, I've got mine" attitude on the parts of the vendors and servicers.

And finally, I'm not at all sure that the large number of Yannies seen in service is related solely to their great performance. I suspect that their use in mass production boats may well be due to fiscal benefits to the manufacturer rather than long term use benefits to the sailor.

Cheers,

[boden36]

I think that part of the problem lies in the production of pleasure boat engines that are more complex than necessary. For example, I would not have a turbo motor in a cruising yacht which is a real knockabout application - better to sacrifice some power to weight ratio in the name of reliability. Even though the turbo was not at fault in this case, turbo or supercharging increases the stresses on the engine, and is not something the average Joe can fix. In addition, as we have seen, it complicates the diagnostic scenario.
In the same way, I am happy to drive my Model A Ford into the desert, but would not take my Honda Accord there!

Regards,
Richard.