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Engine Concepts...

Discussion in 'Technical Discussion' started by karo1776, Aug 10, 2014.

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  1. ranger58sb

    ranger58sb Senior member

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    Starting from my end of the food chain:
    - a proven track record for reliability
    - a proven track record for reliable bolt-ons
    - completely ambidextrous; water pumps, oil/fuel/coolant filters, aftercoolers, turbos, zinc anodes can all be mounted on the inboard side in twin engine installations for easy access during service
    - easy replacement of bolt-ons (alternators, water pumps, heat exchangers, etc.)
    - major overhaul is possible in the boat, in port
    - economical, quiet, clean

    My opinion of weight "depends." Light can be good (save fuel?), heavy can be good (useful ballast?). Depends on boat, mission, and installation.

    I don't much care if it's got belts or suspenders, dry or wet sumps, etc. All of that should manifest itself in a "proven track record..."

    -Chris
  2. kmb1949

    kmb1949 New Member

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    Yachtjocky is right and that is why I am here. (someone else initiated the thread). Even though I have built and run a first engine, there is still time and room for improvement. I know that durability is a concern to everyone, especially me, but with todays test cells, test methods and computer diagnostics, engines are beat to death to reach overkill durability. When the engines reach the market, durability is already built in. Now before a couple of you jump all over me, I accept that some offerings still have issues. If I am remembering correctly, the Cat 3126 had issues with warping cylinders and no producer is immune from mistakes. Here is a link where a customer had issues with a Cummins 6.

    [Mod Note, Link to site requiring registering removed]

    I know that producers are sometimes accused of designing for failure just after the warranty ends but I don't believe it. Producers invest too much to be wanting a bad rep. As I understand it, the Cummins in the link went 6000 hours. According to all I read, customers should expect 5000 hours (before a rebuild) for marine diesels of pleasure craft grade. The problem I see with this, is that Cummins did not respond to the post. It looks like a 6B engine to me and if Cummins had provided a new block and pistons, it would have been great PR. Instead, this post has been on line since 2010.
  3. PacBlue

    PacBlue Senior Member

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    A small engine builder like MTU can spend 25% of the global giant GM's R&D budget? GM, a giant company that can post more in quarterly profits that the other can even gross annually?? Those figures are not even close, I would suggest you read one of their year end financial reports.
  4. rgsuspsa

    rgsuspsa Member

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  5. karo1776

    karo1776 Senior Member

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    Internal Engining Cooling.

    Yes, that is not nucleate boiling... it is film boiling and is what is to be avoided. And, you are right it takes away 98% of the cooling capacity of the system.

    How full film boiling is suppressed is either by increasing pressure and flow. Of the two pressure is more important. How effective can an ebullient system can be ... look at a naval pressurized water reactor plant. 100 -150 MW thats about 140,ooo to 200,ooo hp in heat energy removed from an area about the size of a truck 400 hp engine radiator... with a maximum temperature rise of the coolant water of less than 3 degrees Centigrade or 5 Fahrenheit across the heated surfaces. How is that done with over pressurization and flow.

    Buck engine guy is right marine engines are a special lot. Why is the marine environment is erosive to the internal engine components during any period of non operation. This degrades the cylinder walls and other surfaces internal to the engine. While at the same time during periods of use propulsion engines can run under less than ideal conditions as temperature and loading. In a yacht a well loaded generator left running seems to run forever 20,000 hrs or more... a main might need overhaul at much less than half that number.

    I think keeping the internal engine temperatures constant in operation (I am talking the internal metal temperatures not coolant temperature) constant improves the situation. This is hard to do even with thermostatic control where the coolant stays within a narrow range. To do this requires improving the heat transfer inside the engine and the metal surfaces to the coolant. That is the advantage of an ebullient system.

    Furthermore, I have long thought using aluminum in the engine structure and for the cylinder wall would help. Now that means either high silicon content alloys and special honing techniques or coatings. This would eliminate to a large extent the corrosion of the cylinders during layup. Also, the internal heat transfer of the metal would be much better.

    The negative of this aluminum construction and cylinders is thermal efficiency decreases... but combined with the ebullient system cooling and high temperatures in the coolant this can be actually reversed for a slight improvement.

    Why these are not exploited is the marine market is much smaller market segment than we would like and there the manufactures don't listen much... compared to other segments. Worse the yachting market is a boutique marketplace in many ways... but this allows perhaps some improvements to be made.
  6. olderboater

    olderboater Senior Member

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    I took the numbers from Rolls Royce Daimler's annual report. (Soon to be only Rolls Royce as they're buying Daimler's interest). MTU isn't a small company. It's part of a huge company that spends $2 billion a year on Research and Development. Even if one part of the company is heading a project, all parts may become involved and do benefit if it's successful. And that's part of the advantage of being part of such a large entity. $2 billion is a lot of money.

    And even what GM or Toyota spends may ultimately pass over into the boating arena. Engine building, not just marine engine building, is a huge industry and there is lots spent. Now the smaller companies, like Caterpillar, still dwarf what new startups are able to spend, but their expenditures are just in the millions and not billions, obviously.
  7. kmb1949

    kmb1949 New Member

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  8. Capt J

    Capt J Senior Member

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    I think that is the same issue you have if coolant passes too quickly through a motor. The coolant doesn't have enough time for the heat to transfer. I've always been told that removing the thermostats actually makes the coolant less efficient because there isn't enough time for heat transfer.

    I also don't like the use of Aluminum for many engine parts. Outboards use mostly aluminum castings. Inboard manufacturers have tried it with little success (such as Mercruisers exhaust manifolds that were a disaster), aluminum intake manifolds before they lined the water passages with bronze. Trying to get s/s bolts out of aluminum after they've been in there for several years in a marine engine room is always a disaster. A torch is an outboard mechanics best friend. Even Yamaha has a lot of corrosion issues regarding their aluminum castings that have saltwater going through them. Then you also have strength issues with the bolt holes like you're already facing. Warping castings if they get overheated. Yes, aluminum is lighter. But is it the right material to build an inboard diesel marine engine out of? I don't think so personally.
  9. kmb1949

    kmb1949 New Member

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    I found this to be true with the parallel cooling of individual cylinders. Outlet hole sizes were adjusted to get what we needed.

    Ron,
    I apologize for spelling rigid wrong in my post to you. I sold Ridgid threading equipment for 30 years.
  10. rgsuspsa

    rgsuspsa Member

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  11. kmb1949

    kmb1949 New Member

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  12. rgsuspsa

    rgsuspsa Member

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  13. K1W1

    K1W1 Senior Member

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  14. kmb1949

    kmb1949 New Member

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    I agree with your concerns. My experience with individual aluminum jugs and heads has convinced me that it is however possible to use more aluminum. In my research, I find that diesel engine designers design for maximum rigidity in the primary casting. The main reason, I am told, is to maintain crank journal alignment. Another is that any twisting of the cylinder bank will break the head gasket seal. In the application that I am working on, all of the cylinders are individual. As long as the crankshaft alignment is maintained, the cylinders can actually move around ( a few thousandths). Each cylinder seal is an individual copper ring and there is no continuous, front to back gasket. Before everyone jumps me on this, in all the testing I was able to do, I never lost a cylinder seal. This was accomplished with a much lower head torque number than others use.

    If we use a CGI lower block, an aluminum upper block an aluminum cylinder jugs and aluminum heads, I am confident that we can lower the weight and still maintain the durability. The rigid CGI lower block takes care of the main bearing alignment and the individual cylinders take care of the head gasket issues. All of the primary bolts anchor into the CGI lower block and the rest are secured in "Full Torque" inserts. Nylon sleeves and steel inserts should take care of corrosion concerns for the bolts. I would anodize all of the aluminum parts and powder coat the exposed steel and iron ones. I don't like paint, it always flakes off and ends up in the bilge.

    If there are other approaches you would like me to consider, let me know.
  15. NEO56

    NEO56 Member

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    I just spent an hour out of my life (which I'll never get back) reading this thread, and I'm sorry kmb1949, but everyone on this site is correct and you're wrong....arguing until your blue in the face won't cut it with this group. Drop what you have in a boat...and get some real world numbers, and hours logged, and if what you say is true, and you motor shows some real promise, these guys, olderboater, K1W1, Marmot, Capt J, and numerous others on this site are a wealth of not only information but real world contacts that could probably give you a leg up....it's called networking my friend. So stop p**sing on everybody's boots and telling them that it's raining! I have a buddy of mine who's involved with an inventor who makes a small engine that runs on water...they invited Briggs and Stratton, Bombardier, etc...were supposed to have this big dog and pony show...but two weeks before the "show" they couldn't get the prototype to run longer than 5 minutes...so they're back to the drawing board. I rest my case.
    And by the way...I usually don't start drinking this early in the day...but where's my double tall????
    Last edited: Aug 16, 2014
  16. kmb1949

    kmb1949 New Member

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    I would like to change the subject for a moment. About three weeks ago my 32 year old son Kevin was diagnosed with MS. It seems to be advancing faster than anyone expected. Kevin did all of the 3D CAD work for the project. For those of you who are people of faith and aren't too busy, please take a moment to pray for him. We are all very concerned and I can't imagine moving this forward without him. Thanks
  17. Yachtjocky

    Yachtjocky Senior Member

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    Very sorry to hear that. Hopefully the treatments that are available these days will help.
  18. Marmot

    Marmot Senior Member

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  19. PacBlue

    PacBlue Senior Member

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    You are confusing R&D budgets of the Joint Venture between the whole organizations of RR & Daimler. You have to do more homework and cut out the MTU numbers. Google Tognum Annual Report, which will give you numbers prior to the JV, and you will find the facts for the year 2012 - Total Revenue about 3 Billion Euro, R&D - 241 Million Euro, which runs about 8%.

    A far cry from $2 billion USD (about 1.5 billion Euro) that your are assigning to MTU. That would have been nearly 50% of annual revenues funneled into R&D, a certain formula for a quick corporate death.
  20. olderboater

    olderboater Senior Member

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    I don't have to cut out the MTU dollars only. They benefit from all the dollars spent by the company. The entire entity is power systems and they all benefit across platform. I'm sure some more than others from specific developments. But they are working on implementation today in one business segment based on things they learned in another. There is definite advantage to the marine business from being part of the whole.

    The business as said above is "Power Engines based on two technology platforms, gas turbines and reciprocating engines. That's all the company does.

    I never assigned all the value to MTU. I said Rolls Royce Daimler Power Systems and only pointed out that MTU is part of it. If I led you to believe it was all MTU, then I didn't mean to. But back to the point, there are huge dollars being spent across all industry applications on improving and developing engines. Buck isn't looking at the engine as strictly marine but as a diesel engine with marine being one application. It's not like the manufacturers are just sitting back and doing nothing to improve.
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