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44 Ocean SS real world performance?

Discussion in 'Ocean Yacht' started by Greg Page, Sep 20, 2020.

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  1. Capt Fred

    Capt Fred Senior Member

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    Capt J: If a Detroit is over propped wouldn't you see black smoke? I do not see any black smoke even when trying to achieve rated wot RPM. Also what is normal EGT at 1800 RPM and what would be considered excessive? Lastly what boost pressure would you expect at 1900, 2100 and 2500 rpms? Thanks
  2. Greg Page

    Greg Page Active Member

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    Annapolis MD
    44 Ocean failed survey (never made it to sea trial). Back to the hunt.

    Thanks all for all the information - Greg
  3. Capt J

    Capt J Senior Member

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    You won't necessarily see black smoke.

    EGT's should be 850F or under at 1950, generally under.

    Boost pressure totally depends on who marinized the engine and what size turbo/injectors they used.

    Would start with new primaries and secondaries, clean bottom and a photo tachometer.
  4. Capt Fred

    Capt Fred Senior Member

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    Yesterday I ran the boat to get fuel and these are my numbers at 2000 Rpms, 10 psi boost, 900 EGT, 20 kts. Filters are clean and bottom was cleaned the week before. These are J&T 485 Detroits.
  5. Capt J

    Capt J Senior Member

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    What are WOT rpm numbers? EGT is high, most mechanics recommend 850 (or less) at cruise on Detroit diesel 2 strokes.
  6. Matt Clark

    Matt Clark New Member

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    Sorry a little late on the reply but just seeing this thread. I have a 1990 44 with 1645 hours and it has 671 TIB's. The props were redone last year. I have a bunch of layers of bottom paint as well and I run 28.5 k (34.5 MPH) at 2550 RPM's at WOT and fuel tanks were close to full. I try to run her about 80 off of that (ish) for cruising which is around 2100 RPM which nets around 23 MPH. I love my boat and pray that I can do a long time without a rebuild. A friend who has my same set up finally just rebuilt at 3000 hours! Hoping I can get that out of mine as well.
  7. Capt Fred

    Capt Fred Senior Member

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    Matt, thanks, do you know the weight of your boat, diameter and pitch of your props or boost pressure. I wish I could achieve your performance. BTW the slower you run the longer your engines will last.

    Capt J: The engines can only turn 2250 at WOT and 21 kts with boost around 13 psi. When mine was surveyed, the props were identified as 24" by 27" 3 blade and weight 40000 lbs. The best I can tell I have the props my boat was delivered with, same as spares and all other info I get about Oceans. It also has the right speed vs RPM performance up to 2000 rpm. I wondering if the previous owner de-tuned the engines with smaller injectors.
  8. Greg Page

    Greg Page Active Member

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    A wild chance input: The owner of the boat that failed reported max RPM on port motor when he brought it to his home slip at 2350. My engine surveyor (former head of J & T service) went to look at it on the owners nickel and found a simple adjustment to the injectors (I believe he said the throttle delay setting?) that brought the port motor up to 2500 RPM at WOT. Took him about 20 minutes to adjust.
  9. Matt Clark

    Matt Clark New Member

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    Sylvan Lake, MI
    My weight is 36K dry per original stats in listing so not sure what it is loaded. My props are 3 blade 24 x 27. I had them repitched as they were 24 x 28 as I recall to match the spares. Btw didn't even know I had spares until the surveyor found them during survey which was fantastic as I never looked under the back deck since the lighting was poor at the time. Nice score! Btw I would prefer to run more like 1900 rpms to save my Detroits longevity but my engines just sounds better at 2000 or 2100..Plus on my boat trips which usually entail running with other brands of flybridge boats they tend to like 25 mph so I either keep up or travel alone which ofcourse is not as fun.
  10. Pat D

    Pat D New Member

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    Cinnaminson Nj
    Greg I owned a 1991 44 Ocean which was the last one built.
    I would cruise @22 knots loaded and @ 23.5
    Coming home from canyon trip.

    Never hit more than 26 knots wot.
    I had 4 bladed props and boat ran smooth.

    Great boat, had salon of a 53 ft boat.

    Check the fuel tanks for corrosion!!!