Diesel outboards

Discussion in 'Diesel Engines' started by Pericles, Jul 19, 2020.

  1. brendan gardam
    Joined: Feb 2020
    Posts: 368
    Likes: 43, Points: 28
    Location: east gippsland australia

    brendan gardam Senior Member

  2. Mr Efficiency
    Joined: Oct 2010
    Posts: 9,915
    Likes: 886, Points: 113, Legacy Rep: 702
    Location: Australia

    Mr Efficiency Senior Member

    LOL, things are getting a little tetchy, of course commercial operators get big hours up on engines, taxis a good example.
     
  3. KeithO
    Joined: Jul 2019
    Posts: 307
    Likes: 58, Points: 28
    Location: Michigan

    KeithO Senior Member

    If you are employing someone and paying them, the person works no more than 2000 hours a year. Thats not even allowing for annual leave. I dont know of any business that has a model which requires their outboard to be running 100% of the time and be making money. Nor any scenario where someone is stepped aboard a vessel every minute he is paid. So I'm guessing that most likely drops the annual hours to less than 1000. Now if you have people working the boats in shifts, perhaps you could double that, but how often is that the case with an outboard powered boat ? So it would take 5 years or more to get to 5000 hours. It the drive belt replacement is real, that means 6 drive belt replacements in that time, or a little more than once a year. Maybe you combine that with the annual expensive service where the fuel pumps etc are likewise swapped out and injector seals replaced to prevent expensive failures, if we are talking of 1000 hours a year.

    It just seems like the economics of a conventional inline drive system running off a Cummins Deere or CAT engine would quickly pay for itself compared to an ultra expensive outboard with a questionable track record. And the conditions the inboard could be operated in are so much more severe than the outboard it doesn't even bear comparison.
     
  4. Eric ruttan
    Joined: Jul 2018
    Posts: 190
    Likes: 28, Points: 28
    Location: usa

    Eric ruttan Senior Member

    you say things like you know stuff, but you don't. DK much?
    Continental O-170 - Wikipedia https://en.wikipedia.org/wiki/Continental_O-170

    who are you talking to, and about what?

    You say with such confidence that what you know nothing about. You switch between experimental and certificated motors as if there is no difference.

    I lost your point in the weeds. again, military applications are not market applications. the market, the owners of such aircraft that won WW2, will tell you just how EXPENSIVE they are to maintain. The power levels, costs, and maintenance costs are insane.
    We had liquid cooled V engines in WW2 because that's what we had, and they grew into the power levels we needed. you argue like they beat out other technologies. they didn't.

    if darwin mattered in aviation, ecomotors would not be dead.

    a diesel makes max torque at ~1500 rpm. this is a good match for props. A gear box on a diesel flying machine is dumb.
    It's probably dumb on a floating machine as well.
    and ya, the trany matters, because there is a history of them sucking.

    but, again, way back, you said there were alot of trannies in general aviation. there are not. virtually all the flying machines at the airport near you are direct drive boxers.
     
  5. Eric ruttan
    Joined: Jul 2018
    Posts: 190
    Likes: 28, Points: 28
    Location: usa

    Eric ruttan Senior Member

    you are fibbing. you fail to mention the COSTS to get it to 2100 hours. how much work and what is replaced between 0 and 2100 hours. and, at the end of that expensive program you haul it to the scrap heap. the fact that said engines are operated daily by commercial operators that run them all day, with a professional support staff, not once every other saturday to go get a 100$ hamburger

    you are comparing this to outboards and other motors that get spark plug changes and barely maintained.
     
  6. KeithO
    Joined: Jul 2019
    Posts: 307
    Likes: 58, Points: 28
    Location: Michigan

    KeithO Senior Member

    The O-170: 170lb for a 65hp engine and been out of production for how many decades ???? The O-200 is the smallest flat 4 engine being made and thats a fact. 100hp for the same 170lb.

    PS: I'm suggesting that clients are going to find that its not that cheap getting their diesel outboard to 10 000 hours either, in much the same way as Thielert/Centurion/Continental. You have no evidence to the contrary since no-one has begun commercially selling these engines yet.

    The surviving boxer air cooled engines preceded the Merlins and Allisons by many years. Simplicity is great, but it doesnt scale well. Thats why there are no boxer engines below 100hp because they cant be built light enough, nor can they swing a big enough prop.

    you say things like you know stuff, but you don't. DK much?
    Continental O-170 - Wikipedia https://en.wikipedia.org/wiki/Continental_O-170
     
  7. KeithO
    Joined: Jul 2019
    Posts: 307
    Likes: 58, Points: 28
    Location: Michigan

    KeithO Senior Member

    Whats the formula for power again ???? P = 2*pi*N*T/60 N=RPM T = Torque in Nm
    Thus at 1500rpm the engine would clearly make half the power as it would at 3000rpm and 1/3 of what it would make at 4500rpm.
    If you want very heavy, low output engines, sure - go with direct drive. But if you want something flyable, you have to operate at maximum power which is usually incompatible with direct drive. Even the O-200 is running a prop at 2700 rpm to make its 100hp or else it couldnt and in Reno racing they may be running those engines at 3000rpm or more which is how they go so fast.


    a diesel makes max torque at ~1500 rpm. this is a good match for props. A gear box on a diesel flying machine is dumb.
    It's probably dumb on a floating machine as well.
    and ya, the trany matters, because there is a history of them sucking.

    but, again, way back, you said there were alot of trannies in general aviation. there are not. virtually all the flying machines at the airport near you are direct drive boxers.
     
  8. Magnus W
    Joined: Nov 2017
    Posts: 143
    Likes: 9, Points: 18
    Location: Sweden

    Magnus W Senior Member

    I considered dual Oxe as replacement for my single inboard diesel. But upon contact with Oxe I got, after some pushing because they were reluctant to tell me, info that the engines are due for complete overhaul after 2000 hours (this was circa 2017 so maybe different now). And overhaul estimate is/was roughly the same as a new engine.

    In the end the powertrain net cost per hour was around 16 times higher with the dual Oxe vs inboard medium duty diesel with shaft. Simply way too much for me as any potential benefits hardly outweighs the cost increase. Not mentioning the hassle of replacing engines every 18 months with associated downtime.
     
  9. Boatman1011
    Joined: May 2013
    Posts: 30
    Likes: 1, Points: 8, Legacy Rep: 10
    Location: Florida

    Boatman1011 Junior Member

    Brendan you got me with a link to 1 that made it 10,000 hrs. I suppose having found 1 that made it required a press release from the manufacture. I can tell you from owning a Mercury/Yamaha/Suzuki dealership this is the exception and not the rule. I have seen very few of the >200 Hp models make it past 4,000 hours, and certainly not in the condition I would purchase them.
     
  10. Boatman1011
    Joined: May 2013
    Posts: 30
    Likes: 1, Points: 8, Legacy Rep: 10
    Location: Florida

    Boatman1011 Junior Member

    Your analysis is similar to what I was coming up to myself. Unless the # of running hours was up in the 4,000 - 5,000 range the fuel savings alone doesn't offset the initial investment. However, that amount of hours is going to require rebuilding these high rpm, automotive designed diesel engines. I'm curious what comes from this survey Survey - Diesel Outboard News https://dieseloutboardnews.com/survey/ as it seems to take some of these other factors into consideration.

    I've seen on social media somewhere that they were going to post the results from the survey after it get's to a specific number of entries.
     
  11. Mr Efficiency
    Joined: Oct 2010
    Posts: 9,915
    Likes: 886, Points: 113, Legacy Rep: 702
    Location: Australia

    Mr Efficiency Senior Member

    It does seem as though diesel outboards are a niche market, not a broad one. I think four stroke outboards broke the domination of sterndrives because there is a list of advantages to be had, there is not a similar leap going to diesel outboards.
     
  12. KeithO
    Joined: Jul 2019
    Posts: 307
    Likes: 58, Points: 28
    Location: Michigan

    KeithO Senior Member

    Honestly, I am a fan of the diesel. But the world is highly politicized and there is a new round of emissions regulations making their way down which could kill anything but dry exhaust marine diesels, simply depending on how they get applied to marine applications. And those dry stack applications may look just like what we have today with on road diesels with oxidation catalyst, DPF and SCR systems and possibly a system to pre-heat the emissions system to get it operational in a much shorter time than applies to current EU6 or Tier 4 final applications. While this would mainly impact cost and reliability on conventional inboards, it would be very hard indeed to apply to an outboard. Emissions systems for gas motors will always be much simpler and more compact than what is needed for a diesel. And as I have said before, manufacturers of gas outboards can do a lot to improve their products to lower fuel consumption without much of a stretch at all, like the CVT transmission suggestion.

    We here in the states have mostly been denied the option of economical diesel cars for commuting since VW withdrew their diesel models in 2015. When they brought them back in 2008-9 it was only in the highest spec models which all had price tags of $27k+ Since the VW emissions scandal the only diesels now are in the large SUV's which are very expensive and not even close to an "economical vehicle". Mid $40k and up. The only place one has reliably been able to find a diesel engine has been in the 3/4 ton pickup and up category. Ford used to be based on the Navistar engine, a company just too delusional and corrupt to handle even the first change in diesel emissions in 2007. Today they are basically gone. Their trucks and busses today using mostly Cummins engines. I have an example of the Ford F250 from the 2008 model year, and its an absolute dog. In winter its calibration and thermal management is so pathetic it cant regenerate the DPF over an entire tank of fuel, so every other tankful it returns about 9 mpg while making clouds of smoke and smelling like a badly adjusted kerosene lantern. My truck has just over 100k miles on it btw, I feel fortunate every day that the engine has not grenaded yet... A similar truck today from anyone will cost at least $55k. The only engine I would trust is the Cummins, but the Dodge trucks have other problems associated with the brand that are also not trivial.

    Aside from Ford, the other big player used to be Caterpillar, at one time they had 60% of the HD truck engine market. But their own ACERT engine (high EGR) and 2007 emissions system was not a success and they realized that to protect their primary product (machines) they had to re-assign resources and abandoned the on highway engine business. Few companies could have done what CAT did and survived. Of course that left a lot of truckers in the lurch when there were no more reliable CAT engined trucks out there. Cummins more or less cleaned up in the wake of the Navistar failure and CAT leaving the market. Cummins always had a good product, all they had to do was make a lot more of it. Cummins also had a quite experienced emissions team, most of the other OEMs farmed that part out to a tier 2 supplier.

    For me personally, I think diesel cars, at least in the US are over. I dont think I will get another diesel truck either. If I have the time and energy I may convert an older truck and put either the old Cummins 5.9 or one of the CAT motors into it. Now that the Megasquirt controllers are capable of controlling virtually any modern automatic transmission, one is no longer limited to the few manual transmissions one can still find on the market.

    Most of the Pacific still lives in the pre-emissions world compared to the US and a certain extent Europe. Diesel vehicles and engines are still fairly readily available, which is why one sees so much from Yanmar and Kubota. Those trying to get into making a new product now using diesel engines must be eying the pacific zone as their primary market because the western world is at the point where we are being regulated out of existence.
     
  13. brendan gardam
    Joined: Feb 2020
    Posts: 368
    Likes: 43, Points: 28
    Location: east gippsland australia

    brendan gardam Senior Member

    what is the pacific zone
     
  14. Boatman1011
    Joined: May 2013
    Posts: 30
    Likes: 1, Points: 8, Legacy Rep: 10
    Location: Florida

    Boatman1011 Junior Member

    How about the possibility of the hybrid diesel outboard? I’ve seen OXE indicate this is on their business platform to introduce a hybrid version of the diesel OB.
     

  15. Boatman1011
    Joined: May 2013
    Posts: 30
    Likes: 1, Points: 8, Legacy Rep: 10
    Location: Florida

    Boatman1011 Junior Member

Loading...
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.