Replacing Northern Lights 12kW GenSet Cylinder Head Part I (MV Dirona channel)

[@aktxyz]

Using the wing engine to show what you are doing on the hidden side of the generator ... was brilliant !!! bravo

[@MVDirona]

Thanks for the feedback on the video.

[@art4amor]

This is a compliment to You for the first, second and tirth part video of the description of changing the generator head. The incredible patience during the action amazes me. The love for explaining how and why things work is fascinating. The camera setups are fantastically located so that we can see every movement and effect of the captain's engineer. The questions and answers are specified for anyone who may not know anything about the subject, but still learns almost enough to try to do the same thing himself. Personally, when I screw around my engines, I always have leftover screws or parts. Regards and thank You for sharing.

[@brucebenson9892]

I love the intelligent questions she asks as we watch him work through projects. She has a real knack for keeping us in the loop in a way that helps us see what's going on without interrupting the work.

[@Colinpark]

Yes they make a great teaching team.

[@MVDirona]

Jennifer helps keep me in the loop as well. I find it's super easy to focus on the job and forget to comment or miss pointing out a key check. Jen is good at catching those.

[@galeriafuentes]

Probably one of if not the most informative channels on YT regarding Marine motor yachting. Very technical stuff here! Nice vid!

[@MVDirona]

Thanks. We appreciate the feedback.

[@astrodiver1]

Getting the block deck clean should be a lot of fun. Looking forward to see how you go about that in the next video. Fantastic production, Thank you!

[@MVDirona]

Jennifer is the interviewer, camera operator, and producer and it does takes time so we appreciate your feedback.

[@barrythompson6472]

It’s a pleasure watching you turn a wrench, great to observe an expert process

[@MVDirona]

Thanks very much.

[@captainrick9379]

Well I know James will not sleep till he's got it back together and running! So keep us posted and Thanks for sharing!😎👍

[@MVDirona]

Your are 100% correct. The truth is we're much faster at doing top end engine overhauls than we are at producing videos by quite a great margin :-). The engine is running great. Videos take a long time to get ready to release -- I wish we could find a way to get more efficient at this. We will get it posted as soon as we find the time to get the video complete.

[@mike93lx]

I love keeping small divided tackle box on hand for jobs like this. Tape a piece of paper on the inside of the lid with the grid drawn out so I can label what each part goes to. It's also useful to be able to close the bin when you need to step away or stop for the day, so there is no risk of it all getting knocked over and disorganized

[@MVDirona]

Most jobs I do don't have enough fasteners and small parts to need that level of organization but it could have helped with this one. Good suggestion.

[@fryfrysk]

Your 17 y.o. cat looks great and already far beyond the average age : lively and activ : probably a good reflection of its owners !

[@MVDirona]

We feel lucky that he's still around and healthy enough to chase us around the boat, investigate if we are in a pariticular place for "too long", and generally, still chooses to spend most of his time in the same room as we are working. He's great to have around.

[@cchambard]

Excellent instructor.... Precise and calm with every step. Thank you for the video!

[@MVDirona]

And thank you for the feedback.

[@johnpizzicaroli224]

I know these videos take a lot of time and effort - thank you for the hard work (while doing the hard work). It's appreciated.

[@MVDirona]

They do take time. We keep thinking we are going to get more efficient and, in some ways we do. But, it never gets quick to produce them. Thanks for the comments.

[@patrickp4384]

They make a special set of wrenches for taking lines like that off , the box end is split to fit the line through . Usually will fit between other spacers like you have. Hat you did was fine just a suggestion for new tools.

[@MVDirona]

Yeah, I used to have a set for brake lines back when I worked on cars but that was decades ago. In the boat tool set, I'm far more space restricted but I agree with you and will pick up a set. Good suggestion.

[@robschaffer2189]

Another extremely in-depth and informative video. As I have said before I always look forward to your videos and adventures on your page. I have been around engines and automobiles my entire life. I think watching the progression of technology is a wonderful thing. When James was talking at the beginning of this video about how the generator's engine is small but not "really" small it got me thinking about the Ford Model T. That engine was a 2.9L four cylinder that made all of 20 horsepower and would chug along happily all day long - and some still are with diligent maintenance. I briefly was the caretaker of a 27 T that still had a non-refurbished original engine that just ticked along as smoothly as it did nearly 80 years before I had it. Something to be said about a good solid design.

[@MVDirona]

2.9L at 20hp is amazingly low stress. Amazing that you had an instance running well after 80 years. Our last car was 320hp from the 3.0 liters so the complete other end of the spectrum. Bet it won't be running in original form in 80 years :-).

[@classicraceruk1337]

Love watching these technical videos So cool cheers guys

[@MVDirona]

We both appreciate the feedback.

[@blindekuh8891]

Great video again, thanks a lot to both of you. Quite interesting to watch you doing this on a modern diesel engine, compared to the old Onan MCCK Generator I have under service (the old vessel ...). I also found, that those go back to tractor (Kohler) engines. Very important, because on one side this helps in finding spares and advice. Other great thing about is, that tractor engines are built to last and to be repairable. Looking forward to the reassembly!

[@MVDirona]

Your right about engines with tractor heritage often being long lasting. And, it can also help with spares in some cases. A couple of years back when replacing injectors in our John Deere 6068AFM75, I found myself missing an O-ring. I went to a nearby tractor dealer and asked if they had this part. He laughed, and pointed to a large parking lot of full of Deere green farm equipment and said, they all use that same base engine.

[@davedoe6445]

Thank you for sharing your expertise on how Diesel engines are put together and operate.

[@MVDirona]

We'll thanks for the feedback. We would both slightly prefer to not have to open the engine up it was only a day of work so really not that big a deal. It'll be interesting to see how many hours it can deliver with the new cylinder head. One comparison that I thought was interesting is, if the engine where in a over-the-road truck and it averaged 40 mph, then the 6,700 hours it delivered before needing a valve reconditioning is 268,000 hours. Not as much as we would like but still far from a disaster. It's a good little engine.

[@davedoe6445]

@@MVDirona It is. If it were on a truck it probably wouldn't be subject to heavy seas backwashing through the exhaust system, like your atlantic crossing hypothesis. Perhaps some clever fellow can engineer a slightly better exhaust valve system that's reliable for exhaust but also prevents backwash.

[@MVDirona]

Yes, you're right, it wouldn't be a problem on tractors and trucks since they use water-to-air heat exchangers (radiator) and dry exhuast. One solution might be an insulated exhaust elbow that moves the mixing of water into the exhuast further down below head. But that would take careful design and require quite a bit of custom fabrication. I don't see a simple solution.

[@Dan-sd5bm]

Thanks for taking the time to film the diagnostic and repair it's really helpful Thank You.

[@MVDirona]

Thanks for passing that along.

[@theresnobodyhere5778]

the big reveal head off was half expecting a big oily damp carbon mess on number three ,fuel burn and compression side of things all looks perfect,your diagnosis was spot on love to see those valve seats,so could be needing better hardened valve seats but also could be most likely needing a stronger valve spring theyre too weak bounce on them so they chatter and leak causing seats to burn black and overheat hmm the wonders of the combustion engine,,, great video loved it

[@MVDirona]

This particular engine uses integral valve seats. They are just part of the head. I don't know if that portion of the head has been hardened. I agree the valve sprints are surprisingly light on this engine. And the valve heads weren't polished on the old head as I'm used to seeing on gas engines. Generally, the vales on the head that came off don't look great from my perspective (shown in the next video). I suspect they have been leaking. However, even with those concerns, this engine has many owners reporting 15,000 to 20,000 hours and few longer at 30,000 hours. They seem to often do quite well. More in the Part 2 video and we'll see what we learn over the next few thousand hours on the new head.

[@TonyMoller]

What a treat! Been looking forward to this video and It delivers as every video from M/V Dirona does. Tusen takk 🇳🇴 🇺🇸 Thank you so much 🙏

[@MVDirona]

Appreciate the feedack and working on part 2 now.

[@seatravel8536]

Awesome video. Great narration James and fabulous questions Jennifer! Great team.

[@MVDirona]

Thanks for the comment.

[@fryfrysk]

Love to see you working on this engine , James with the to the point questions of Jennifer : relaxing co-makership and equally relaxing to watch as a spectator. It is truly a simple , not fancy, but straight forward and honest engine, which can rather easily be maintained by its owner ( of course well prepared comes in handy and prevents unpleasant surprises). Nice to hear it was originally designed as a tractor engine

[@MVDirona]

You are right it's a very low tech engine with only 20 hp from 1.5 liters, no turbo, no after cooler, 2 valves per cylinder, simple mechanical injection, and all discrete component electrical control. It's not complex and Northern Lights parts pricing is usually pretty good. Our Deere main engine is the opposite end of the spectrum wiht high pressure common rail, proprietary engine management system without cost effective owner access, tubcharger, aftercooler, 4 valves per cylinder, and all fly by wire. The upside is it's very efficient and requires just about zero service. In 11,000 hours, it's has a set of injectors and that's it.

[@oliverb.endoriel490]

Like always excellent content 💪

[@MVDirona]

Thanks for the feedback.

[@jiefflerenard1228]

I got hypnotized the minute you started, intelligent explanations! How come you know so much, maybe none of my biz though .I was amazed how easily the heat exchanger went out ,does it means it is fresh water (twice) cooled Thank you for sharing

[@MVDirona]

Thanks for the feedback on the video. In my distant past I was an exotic car repair mechanic. I didn't work on diesels so, in many ways, a very different world but there is quite a bit of overlap. On the engine cooling system, yes, the engine is cooled by circulating sea water through the heat exchanger and then spaying the sea water into the exhaust to cool the exhaust flow. The engine, like most water cooled automobiles, circulates coolant (antifreeze in most cases) that is cooled by the heat exchanger. Essentially, it's the same as most cars in cooling design except rather than using a water-to-air heat exchanger, it uses a water-to-water heat exchanger.

[@rkspdx]

Great video! This is not an easy job and your methodology makes it look easier than it is.

[@MVDirona]

I admit I wasn't looking forward to it but, having now conmpleted the job, it's really quite an easy engine to work upon. And Jennifer's questions prevent me from getting distracted by the work and forgetting to point out important details.

[@chuckoman]

Thank you for excellent explanations and the details , time and work you put in are shown Thank you both

[@MVDirona]

Thanks for the feedback on the video. Much appreciated.

[@Helmut_aus_N]

as I expected: great Job, great Video. Thanks for showing me, what a man can do, if he is cool :-). I'm looking forwardto seeing the next part..

[@MVDirona]

We appreciate the feedback and we're currently working on part 2.

[@gfroese4799]

You really need to get yourself a set of tubing wrenches . Using open end wrenches on tubing nuts can distort them and that can lead to a whole set of problems like fuel and oil leaks . Most of learning is doing . And for the most part your doing fine .

[@MVDirona]

Yeah, I used to have a set of tubing wrenches for brake lines back when I worked on cars but that was decades ago. In the boat tool set, I'm far more space restricted but I agree with you and will pick up a set. Good suggestion.

[@thomasmcclellan1466]

Another great video team Dirona.

[@MVDirona]

Thanks from Jen and I.

[@wjb2]

very interesting Video, well shot, and excellent audio explanations. Mind considering your work experience it is to be expected. Thank you so much for taking the time to produce these videos. Looking forward to the outcome video.

[@MVDirona]

Jennifer ends up carrying the bigger load on these videos where she is the interviewer, camera person, and producer. Thanks for the feedback.

[@hannibalwantsahuggrande3433]

I never knew Doc from back to the future fixes diesel engines!

[@garyengelman7867]

You need to keep a 1/2 inch braker bar handy, would make the work much easier. Lol, still good job.

[@MVDirona]

I do have a 1/2 braker bar and do use it on the big engine but, on these little ones, I don't find it necessary. But, no debate, it's a good choice when barring over an engine.

[@Colinpark]

I always wear gloves working around diesel fuel, it can cause a nasty reaction that can happen over time and exposure. Also for the push rods I take a piece of cardboard and number a line of holes and put each push rod into a hole, that way you can't get them mixed up. Looks like a nice clean, dry, well lit place to work and of course a Feline supervisor to interrupt you for attention at critical moments.

[@MVDirona]

I like to keep my hands clean so I either wear gloves or wipe them frequently or both. Gloves are never a bad choice and they are strongly recommended when working near higher voltages or bleeding high pressure lines. I didn't when bleeding the lines to restart the engine and should have. Thanks for the recommendation. And you're right Spitfire will usually come down for an inspection if we're in the engine room for more than a few minutes at a time.

[@10bbremer]

Manuals- I bit the bullet and paid for the Yamaha Outboard shop manual. Best $80 spent so far.

[@MVDirona]

Northern lights did one better: They didn't charge for manuals and provided them in electronic form. I agree it's good to have the manuals.

[@AndyMillerPhotoUK]

I believe you said you were a more mechanic in a previous career. Changing a cylinder head is not something I or many like me would do trivially -- daunting is an understatement. Certainly, my rule would be only if I absolutely had to -- otherwise I would be in the hands of a professional (like you). This goes to the competency/safety of owner/skipper/crew AND the range of spares said owner/skipper/crew should have access to onboard. You and your partner are clearly highly capable and should be applauded for sharing with us your works on video (and on your website) On your website you state "Our goal has always been to never have a trip delayed or cut short due to equipment issues." (mvdirona.com/2018/02/managing-spares/)as a result you carry a "super set" of parts and spares -- your video on replacing that Gen Starter Motor indicated that not only do you operate a very efficient and organised system but you had 2 spare motors, and a host of other items. I was amused to see that you considered carrying a spare prop and a spare Olympic boiler and made an informed decision on why not carrying these items would be safe and more practical. My conclusion is probably similar to yours -- "Choosing what to carry is based partly on our cruising area, the difficulty of obtaining a replacement, the probability and impact of failure, and the inconvenience of not having that piece of equipment available. The further we cruise from our home waters, the more we want to carry a spare rather than rely on obtaining it in-country or via shipment from the US. That’s one of the ways we avoid having a trip delayed. In determining what to carry, we try to think of anything that could fail that we would be a trip-ender, or just highly inconvenient to do without, and we could reasonably carry a spare for." However, my take on it is "no matter who is doing the work" the right parts and spares should be held on the vessel to allow regular maintenance, minor faults and possible also major breakdowns to be fixed remote from home waters. Yes, as you say, this adds a little weight, and of course there is a cost; but -- if you do it your way -- you control the supply chain you control the time needed before work can be completed and the quality of parts, spares, and consumables -- be these water pumps or 50 gals of Shell Rimula R4L (E9) oil. I believe that I have to be able to complete basic checks, servicing and minor maintenance tasks for any vessel I use -- but to go beyond this one has to have talent and experience and shear gumption that I do not. As I look at the 72 line items on your DironaMaintenanceSchedule.xls -- most (about 55 out of the 72 items) seem to be in reach for someone like me with very basic capabilities (checking and changing oils, filters of many types and servicing the Racors and water strainers, adding antifreeze and maintaining/replacing impellers, checking and applying grease, checking belts YES - replacing belts depends (you had prepositioned a replacement belt for your gen so that you did not need to take the gen apart to fit a replacement -- I could fit a prepositioned belt, but not install a new one since it requires disassembling the generator), testing batteries OK; managing fuel, adding fuel treatment and polishing fuel and draining off water or sediments all fairly basics once you have worked out how the manifolds work. Changing engine Zincs, being able to service and maintain the water maker is important and should be learned). But others like adjusting valves, changing bearings, changing the harmonic balancer, or undertaking difficult, dangerous (work at height) or heavy work on the vessel when it has be lifted out and almost any work to the vessels systems, electrics and A/C and work in very confined spaces would be well beyond me. I would and will continue to rely on a combination of authorised specialists and just good yards and mechanics to do these types of task. AND yes I will have to limp home or call for help if something big breaks and I am far from land.

[@MVDirona]

Your position is perfectly reasonable. It's 100% your choice and whatever contributes most to your enjoyment. For us, self sufficiency brings great satisfaction and we greatly value our time so learning to do things ourselves, seems like the best answer. But, for many others, they can afford to pay someone to fix it so why waste time themselves? And there are lots of positions between them. The most common reason why owners don't service is perceived lack of ability. What I've found over the years working in a lot of different areas, is that if your patient and thoughtful, there is a very good chance you will be able to do better work than many professionals. You won't be faster but, in most cases, there is no reason why you can't equal or better the work of a professional. Admittedly there are jobs where there are tricks or techniques that aren't well documented and finding these by experimentation can take a lot of time. Weather you do the job yourself or just learn enough about it to be able to know what is wrong, what parts you need, and what skills to look for it, increasing your level of knowledge of on board systems always helps. Your thoughtful and analytic approach will serve you well wherever you decide to go.

[@darrylmcleman6456]

Great Stuff!!! And a Cat Scan Too!!! CHEERS

[@MVDirona]

Yes, Spitfire often makes an appearance especially on the longer jobs.

[@juhaturu849]

Will you show us what was wrong in the old head? Great video.

[@MVDirona]

Yes, we'll show the reassembly and starting of the engine in the next video (part 2) and we'll have a look at the old head and see what we can learn from taking the valves out if it and looking more closely.

[@SkypowerwithKarl]

When you got the head off, were you able to see a visual problem with the valve? Receded, burnt etc.

[@MVDirona]

Valve seat had recessed way into the head. No need for tools. You can see the problem from a couple of meters away. Then the question is why? Is this just valve seat wear (some fail earlier than others), or is there some other fault in the engine contributing to the problem? Will get that second video up as soon as we can.

[@SkypowerwithKarl]

MV Dirona Several things can cause it to recede. High localized water temperature, insufficient valve lash, weak valve spring, worn valve guide. With a new head and gasket, you’re back to new, but check your lash again after a few hours since most seating is early on. Check your heater core, annual impeller change.

[@MVDirona]

That's a good list of problems that can cause early valve seat failure. On wet exhaust marine engines, there is one other: salt water intrusion coming up through the exhaust system. We can't find any evidence of problem in the exhaust system after having checked it carefully but we'll keep an eye on the valve lash as you recommend. The manufacturer recommends re-adjusting the valves at 50 hours so we'll do that.

[@SkypowerwithKarl]

MV Dirona What I’ve seen, is when an owner doesn’t let the engine get good and hot(test to see if it starts). The exhaust port is only warm enough for steam to condense and rust the valve stem of an open valve. Iron oxide is an abrasive and either sticks the valve open or wears the valve guides. I cringed when they start an engine, blip the throttle a few times and shut it down. You have quite an investment in the yacht. Probably one of the most useful tools I have is a thermal imager. You can take pictures around the engine room when things are operating normal at temperature to establish a reference “baseline”. In the future you can tell if part of an engine is abnormally hot like part of a head or riser. The first day I used it, it paid for it’s self. I was outside and panning around and found the shore power connection on my boat was glowing bright. I touch it and almost got burned. I had AC on and charging the inverter bank and I was pulling about 25 amps. The socket in the hull was corroded which caused resistance and heat. It was starting to melt the wires inside. It could have burned a hole in the fiberglass around the outlet and ruined my plugs. I use a “FLIR One “ . I highly recommend this brand just make sure you get the latest version/ generation and make sure it fits your phone.

[@MVDirona]

I have a Flir One as well and every 6 months scan the electrical boards under high load and all high current connections. We haven't found anything with it yet but we did have a loose connection at a DC shunt when the boat was around 2 years old that was so hot it was visible in the visual spectrum. A bolt was glowing red and the galvanization was gone. We re-torqued everything and haven't seen any problems since but a great many boats meet there end this way on electrical issues. On the engines, I do use an IR heat gun to check port temperatures under load looking for a weak cylinder. On your theory that the exhaust valve problem was rust related, I think you are right. I took apart the old head and there is some evidence of corrosion. I'm working a few theories on that but, at a high level, I'm leaning towards: 1) in extreme conditions, water will splash in from the water lift mufflers and sit there for a week or 2 and 2) when the engine shut down some steam and atomized water is light and it's only a 3 inches back into the head and we end up with high humidity and salt in the valve area and, as the engine cools, it all ends up damp. The second would be a design issue and hard to address other than ensuring the engine gets properly warm on each startup as you recommend. The first issue would be mitigated by running the engines after extreme conditions so water doesn't just sit there for long periods of no generator use.

[@PeteHuntley]

When do we get to see part 2, great vid.

[@MVDirona]

Your right. We intended to have it completed before now but we've been busy. We've left Scotland, crossed the North Sea, and are now in Norway. But, we woke up to rain this morning so there is a good chance, we'll get it done today. Thanks for the feedback on the videos. That too helps us get going on that least favorite task of preparing a video to be posted.

[@James-seafan]

very interesting video may I ask is the main engine in the background and how much horse power please

[@MVDirona]

Thanks for the comment. The main engine in the background in a John Deere 6068AFM75 M2 rated at 266 hp with 11,190 hours on it. It's been impressively reliable and we're really happy with it.

[@James-seafan]

thank you for the info

[@markvolker1145]

6,000-7,000 hours isn't many hours for diesel engine... Everything in the oilfields runs on diesel due to their longevity, reliability and for the fact that diesel doesn't explode and in some applications they'll run constantly for months at a time so it's not uncommon to find engines with 10,000-15,000+ hours without having any internal failures.

[@MVDirona]

I agree it's a low hour failure. The main engine has 12,600 hours and has never had any service other than an injector change at 8,000 hours. These little generator engines are simpler and less expensive engines (parent bore, 2 valve, mechanical injection) than our main engine or the engines you are used to working upon. Nonetheless, there are many reports of these little guys doing 20k to 30k hours so this failure was definitively early.

[@James-seafan]

hi Jennifer and James Hamilton may I ask are the return lines returning fuel to the engine or the tanks thank you

[@MVDirona]

The return lines return fuel back to the fuel tanks. Most diesels use return fuel to cool the fuel pump and injectors and fuel not used in injection is returned to the fuel tanks. On our engines, they circulate far more fuel than they burn so most of the fuel is returned to the tank. Since all the return fuel flows through all the filters, this has the side effect that most of the fuel in the supply tank is filtered many times before it actually burned.

[@James-seafan]

thank you for the information mv dirona

[@larsrosing5033]

Hi again! What's your background, you know an awful lot of engines, maintenance and systems as well?

[@MVDirona]

My current role is VP and Distinguished Engineer at Amazon Web Services focusing on infrastructure efficiency, reliability, and scaling. That role doesn't have much overlap with marine mechanical systems although we do have a very large fleet of 2.5 MW generators. Some problems in common although our 3 cylinder is quite a bit smaller than the big V12s at work and generator health isn't really a big part of my current job. Overall, my work life doesn't overlap much with the boating stuff unless you look way, way back. 38 years ago I was a professional automechanic servicing exotic Italian cars. Not one of them were diesel but, overall, that role had a lot of overlap with boat servicing and that background is actually fairly useful around the boat. I wish I hadn't sold my 5' high tool box :-).

[@brucebenson9892]

Some of us may know our way around a diesel engine but lack the experience to tackle this kind of job. Would it be practical to set up real-time appointments with a mechanic and broadcast the steps we are taking, getting the virtual mechanic's feedback and guidance as we go?

[@MVDirona]

Sure, absolutely. With some guidance even if just over the phone, just about anyone with care and patience could do much of this work. I can think of two times when we were in ocean crossings where we consulted with the the boat manufacturer (Nordhavn) or the stabilizer manufacture (American Bow Thruster/TRAC) by sat phone and it worked great.

[@simonhantler8062]

All the gear but no knee pad

[@MVDirona]

We do have knee pads for both of us onboard and we use them fairly frequently. We also have a a square knee mat that I use less frequently. But, when doing engine work, I often don't use either unless I'm in the same location for a while.

[@vynleshmynle7372]

So this is why you never see Nordhaven owners on their boats. There in the engine room fixing tings

[@MVDirona]

We have managed to squeeze in a trip around the world, been way up north of the Arctic Circle, been to the southern end of New Zealand, enjoyed a season in the South Pacific, and lived on the boat for 3 months in Waikiki, a couple of months in London, 8 months, Amsterdam, a month in Sydney, Helsinki, and Stockholm, and seen a lot of nature along the way (mvdirona.com). It's been a pretty good trip.

[@halildjencic1612]

Exhaust/coolant combination, is that something like EGR cooler ?

[@MVDirona]

Marine engines are typically cooled using a heat exchanger or a keel cooler. A heat exchanger is a coolant to sea water cooler that is used to cool the engine (similar to a radiator on an over-the-road vehicle but water-to-water rather than water-to-air). A keel cooler is a coolant to sea water cooler that is mounted outside the hull of the boat to cool the engine. On the first approach, sea water is piped into the boat and it flows through the heat exchanger and on the second type coolant is piped outside of the boat to be cooled by sea water in an external keel cooler. In this engine, a heat exchanger is used and the engine design combined the exhaust manifold and heat exchanger in a single casting which is a bit simpler and might save some space. It's a simple engine without advanced emissions reduction techniques like EGR. It's a 2010 installation but, back then, low power engines had very few exhaust emission restrictions. The main engine is a EPA Tier II engine so it is a much more advanced engines and current generations boats are using Tier III engines with even more.

[@halildjencic1612]

MV Dirona oh ok, thanks for the info, I love these videos, I spent all my spare time watching them, I’m a tech at Volvo/Mack dealer so it’s kind of my job 😂

[@MVDirona]

Thanks for the feedback on the video. Since you work on over-the-road trucks, you'll see all the latest tricks and techniques to meet difficult emission requirements.

[@halildjencic1612]

MV Dirona yeah lots of tricks,not so great designs though,lots of failures but keeps us techs in business,lol

[@MVDirona]

Yeah, I agree. In the early days of emissions regulations, I thought some of the forced changes actually helped. But the more recent restrictions lead to complex designs or much less efficient engines and sometimes both. My main engine is a perfect example. The only difference between a Deere 6068AFM75 and a 6068AFM85 is the former is Tier II and later is Tier III. All the same ratings. The Tier III engine is 15% less fuel efficient at full rated output. Those that don't give up efficiency, pay in really complex designs that keep folks like yourself busy :-).

[@restorationde9214]

This is the first time I know your channel. Can i make friend with you

[@marchingontogether2571]

could you not just do a compression test to find the fault

[@MVDirona]

The fault was well understood at this point. The valves were adjusted and around 30 hours later needed to be adjusted again. Then around 20 hours later the #3 exhaust valve has again closed up. At that point, there are really only two options: 1) receding valve seat, and 2) stretched valve. The later would be super unlikely on this low reving, low output engine that has never been overheated so it's just about guaranteed to be a receded valve seat. Either way, the head has to come off so we were pretty confident in the work that would need to be done and order all the parts up front.

[@missingremote4388]

Why wouldn't it fail ?

[@MVDirona]

I guess you are right it would definitely fail. The question is when? I would like to get 15,000 hours before taking off the head on a low stress diesel. 6,700 hours isn't a disaster by any measure but I would prefer to get up over 10,000 hours. And, many operators of these generators report 15,000 to 20,000 hours with a few reporting as high as 30,000 hours. But a top end overhaul isn't that big a deal and, if the engine goes to 15,000 before needing a full overhaul, I'll feel like it's done fine.

[@56Spookdog]

👍👍

[@robertmore8373]

Can you put the camera in the galley so I can watch you meticulously explain how you make then eat a sandwich. It’s all very riveting. Keep up the good work.

[@MVDirona]

I freely admit that changing a cylinder head may not be spell binding for most people but we chose to blog (mvdirona.com) or video (kzbin.info) jobs we need to do maintaining the boat and places we have got to using the boat.

[@robertmore8373]

MV Dirona Actually I did find it riveting. My comment was a testament to your abilities to narrate a given topic. You could probably make watching paint dry interesting by narration.

[@hedhtr4]

Where are you in your travels?

[@MVDirona]

We're in Stornoway Scotland and, if Norway opens up, we'll probably go there next.