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Considering Repowering Again

Discussion in 'Technical Discussion' started by DOCKMASTER, Jul 24, 2019.

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  1. Capt J

    Capt J Senior Member

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    I agree with all of this. But my question is why even bother repowering in the first place if you're happy with how it performs now and everything is running well. If something grenades, then do the repower, is what I would do. I love C18s and feel they're are great choice. Yes, you'll gain probably 3 knots and lose some fuel burn at cruise (85 GPH versus ?), but on the troll and 1000 rpms and under the Detroits are a lot more efficient than the C18's.....so depending on your usage you might not see any fuel gains overall.
  2. Capt Ralph

    Capt Ralph Senior Member

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    OP stated hard to find parts DD and old DD techs.
    I luv new fancy things but also in the school of never kicking a sleeping dawg.
    In Alaska it may be if it's not broke, don't fix it.
    But, it's still his check book.

    It's been 55 years sense I was in Alaska (Army baby). If you can not find a DDC tech, Tap on us.
    Last edited: Sep 2, 2019
  3. DOCKMASTER

    DOCKMASTER Member

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    I'm repowering for the reasons mentioned. Difficulty in finding parts and service, especially for the DDEC electronics. I like the idea of getting rid of the remote trolling valve actuators and cables and having a simple plug and play. I hate that the DDEC stuff is all 12v and the starting /charging is 24v. This makes me have batteries and chargers just for the 12v DDEC. More stuff I can get rid of. The Detriot's have tons of hoses and hose clamps. Everything is moved around the engines in hoses. I have had several hose clamps break causing problems. We went through and changed all the hoses and clamps and have had failures of new clamps (yes, the expensive t-bolt style). I have an opportunity to get a good deal on the CAT's and I have some specific business reasons that make the timing right to do this now. I'm not doing this for the sole purpose of fuel savings. That wouldn't remotely pencil out. I'm also doing this now because the true master craftsman that does all the work on the boat is talking about retiring next year. I want to get this done while he is available to lead the effort. I need to replace my gens too so much easier while the engine room is open. There isn't any one resaon, just a lot of little ones.
    I thought about selling the boat and getting something that already has C18s or C32s. I'm going to be about the same, maybe aa little less by repowering but I'll have brand new engines and gears. Further, with a newer boat I would have to start all over again outfitting it for Alaska. We have spent 7 years and tons of money and effort getting this boat where it is. I don't want to do that over again.
  4. Capt Ralph

    Capt Ralph Senior Member

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    Good post and understood.
    Slap Dab....
    You have a dream and plan; Lets get this in motion.
    How can I help from North / east Florida?
  5. Capt J

    Capt J Senior Member

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    That being said, then go for it. I'd go with Onan's over NL's. They just seem to have better computer monitoring and computer system on them. Nothing wrong with the NL's either. I'd prefer NL's over Onan's on boats that run lots of hours on them per year. But Onan's for your application.
  6. Capt Ralph

    Capt Ralph Senior Member

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    KISS
    Northern Lights..
  7. DOCKMASTER

    DOCKMASTER Member

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    I'm partial to Northern Lights. I've heard nothing but good things about them. My current set-up is a 20kw and an 8 kw. The 8kw meets most of the demand and is what I run all day. I only run the 20kw if I have high loads like the washer/dryer, water maker , A/C, etc.

    What I would really like is to install 2(ea) of the NL 9kw units and be able to run either one independent for day use then be able to parallel both during occasional peak loads. I will talk to NL to see if they can offer this. I don't need any type of power management or auto start/parallel feature. A manual switch to select either gen or both would be perfect if possible.
  8. Capt J

    Capt J Senior Member

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    I'd rather have one that can run the entire boat and a smaller one. If you sell the boat with 2-9kw's it would be very undesirable to anyone in a Southern location. Here we'd want 2-20's. But 1 20kw and a 9kw would be ok for buyers, but not the preference.

    NL's aren't KISS anymore, they're computer controlled and everything just like anything else to meet EPA mandates.
  9. Capt Ralph

    Capt Ralph Senior Member

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    Uh? Installing a new 20 and 12 in a Hatteras now.
    There is a fancy & expensive power control option.
    NL is still simplicity at it's finest.
  10. Capt J

    Capt J Senior Member

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    That's great. The new ones I've seen all had an electronic display and computer control.
  11. Capt Ralph

    Capt Ralph Senior Member

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    You need that fancy junk for the inverter to auto start the gen-set.
    Nice LCD panel local and remote like the Oh-Nos.
    The NL gen-set does not need this gizmo to run.
    Still two lil relays in the connect box that we've seen for over 20 years now.
  12. DOCKMASTER

    DOCKMASTER Member

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    That's a perspective on 1(ea) 20kw and 1(ea) 9 kw that I hadn't considered. I will have to give this some more thought. I don't have room for 2(ea) 20 kw and besides most of the time it would be terribly underloaded. The 20kw will get almost no hours. But at least I can get a 9kw out if I had to replace it at some future point. Going back with a 20kw and a 9kw would be easier since that's what I have now.
  13. Capt J

    Capt J Senior Member

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    That's what I'd recommend, even if just for resale. A 9kw and a 20 kw.
  14. DOCKMASTER

    DOCKMASTER Member

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    I spoke to soon on going with the 1.525:1 gear ratio. Upon closer investigation discovered the existing gears are 1.66:1 (not 1.60 as thought). So now likely going to go up to 1.757:1 as this is closer to existing then going down to 1.525:1. CAT also tells me that slower shaft speed with more prop pitch is preferred vs higher shaft speed and less pitch. So the 1.757:1 likely works best. This is also a more common ratio than the 1.525 so hopefully lead time improves on the gears.
  15. PacBlue

    PacBlue Senior Member

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    The 1.757 gear is better as noted but puts you in a slight dilemma as the safety factor for the AQ 22, 2.5” shaft falls below the industry standard of 5.0 for your application, as it is now 4.0.
    Not much you can do about it other than accept it as is or upsize the shafts which is another expense.
    You will also be getting a different prop with the different gear ratio, but have awhile to go for that decision.
  16. DOCKMASTER

    DOCKMASTER Member

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    Can I not simply add some pitch to existing props? It seems like not much change from 1.66 to 1.757 but maybe I'm underestimating. No, I'm not planning to change shaft size.
  17. PacBlue

    PacBlue Senior Member

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    The short answer is you will have to wait and see and it depends on the condition and material of your existing propeller. When it gets hauled let us know the model make a size with a picture, and what your prop shop says.
    One other thing to keep tabs on - try and mark your waterline with tape as soon as possible. Then when you relaunch, check where the tape sits on your new waterline, to get an idea if you are lighter or heavier and by how much. Tape it at the transom corners, maybe at the aft salon bulkhead area and the bow, just a simple eyeball test to see how she refloats.
  18. Capt Ralph

    Capt Ralph Senior Member

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  19. Capt Ralph

    Capt Ralph Senior Member

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    Since we all enjoy spending other peoples money, May I make some suggestions while your on the hill;

    Replace strut thru bolts. Inspect every bolt and hole for signs of issues.
    If your shafts are in good shape and in good alignment, just replace a few bolts at a time.

    Have the shafts well inspected.

    If your getting new shaft couplers to mate with the new clutches, pull the shafts, have them well inspected and properly fit and true the new couplers.

    New shaft log bellows/hoses. Service/update log glands.

    Inspect rudder post and logs. Service/update log glands.

    All hard to reach thru hull hardware inspected.

    Clean, clean, clean, clean and paint the bilges.

    Consider low bilge water type pumps in the best locations with the large de-watering pumps.
    Including sumps for condensate accumulation. Keep the pretty bilges dry.

    You are already making comments on a new R/O system.
    Lots of comments on YF about control panels and cost of service on some models.
    KISS here also for the long run.

    KuChing, KuChing $$
  20. DOCKMASTER

    DOCKMASTER Member

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    Thanks for all the great input.

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