Sea Sled madness. It’s in my brain.

Discussion in 'Fiberglass and Composite Boat Building' started by DogCavalry, Nov 11, 2019.

  1. DogCavalry
    Joined: Sep 2019
    Posts: 3,347
    Likes: 1,687, Points: 113
    Location: Vancouver bc

    DogCavalry Senior Member

    IMG-20230616-WA0000.jpg Come visit, everybody!
     
  2. Geno67
    Joined: May 2023
    Posts: 90
    Likes: 35, Points: 18
    Location: Old Florida

    Geno67 Clueless Member

    I get sore and cold just looking at that. It's gorgeous DC.
     
    DogCavalry likes this.
  3. DogCavalry
    Joined: Sep 2019
    Posts: 3,347
    Likes: 1,687, Points: 113
    Location: Vancouver bc

    DogCavalry Senior Member

    It's a cool grey day today. 21°c, 70°f

    Rained earlier in the day, sun coming out for a beautiful sunset.
     
  4. Geno67
    Joined: May 2023
    Posts: 90
    Likes: 35, Points: 18
    Location: Old Florida

    Geno67 Clueless Member

    Flat as a pancake and cool at 89 here. It's actually quite pretty though. We have live oaks in the front yard and palm trees in the back.
     
    DogCavalry likes this.
  5. fallguy
    Joined: Dec 2016
    Posts: 8,061
    Likes: 1,828, Points: 123, Legacy Rep: 10
    Location: usa

    fallguy Boat Builder

    Get well John.
     
    DogCavalry likes this.
  6. fallguy
    Joined: Dec 2016
    Posts: 8,061
    Likes: 1,828, Points: 123, Legacy Rep: 10
    Location: usa

    fallguy Boat Builder

  7. DogCavalry
    Joined: Sep 2019
    Posts: 3,347
    Likes: 1,687, Points: 113
    Location: Vancouver bc

    DogCavalry Senior Member

    Lots of good engineering there. Two speed transmission in the leg, so the torpedo is small for the power. Contraprop gives about 11% more thrust for the input. Edit: on average. Extensive testing shows between 6-16% improvement. I averaged to 11%.

    Also grotesquely expensive. Certainly be an upgrade though. I'll bet they sell plenty. World is full of folks who want to be a few inches taller by standing in their wallet.
     
    Last edited: Jun 20, 2023
    Darkzillicon likes this.
  8. DogCavalry
    Joined: Sep 2019
    Posts: 3,347
    Likes: 1,687, Points: 113
    Location: Vancouver bc

    DogCavalry Senior Member

    Brake-Specific-Fuel-Consumption-BSFC-with-operating-points.jpg
    And here's why boats should have multispeed transmissions.
     
  9. baeckmo
    Joined: Jun 2009
    Posts: 1,746
    Likes: 757, Points: 113, Legacy Rep: 1165
    Location: Sweden

    baeckmo Hydrodynamics

    Fuel mapping is depending on the specific use and required characteristics of a given engine. You can have different versions of the same engine with different fuel maps, for instance with the bep closer to the mep/rpm parabola in a version for a marine purpose, fixed gear, fixed pitch propeller. Note that the required power for a planing hull is not a "clean" mathematical curve, but has a "hump" corresponding to the resistance increase in the planing hump region. So, it depends......!
     
    DogCavalry, Ad Hoc and Barry like this.
  10. Ad Hoc
    Joined: Oct 2008
    Posts: 7,964
    Likes: 1,831, Points: 113, Legacy Rep: 2488
    Location: Japan

    Ad Hoc Naval Architect

    Indeed!! :D
     
    DogCavalry likes this.
  11. DogCavalry
    Joined: Sep 2019
    Posts: 3,347
    Likes: 1,687, Points: 113
    Location: Vancouver bc

    DogCavalry Senior Member

    Well yes. It's engineering, therefore it's always compromises. But even a second gear, like that new 600hp Verado, let alone 6 gears, like a drag boat, lets the operator spend more time close to the best part of his curve.
     
  12. DogCavalry
    Joined: Sep 2019
    Posts: 3,347
    Likes: 1,687, Points: 113
    Location: Vancouver bc

    DogCavalry Senior Member

    Why the heck does my etec 250ho overheat at 189°?
     
  13. Darkzillicon
    Joined: Jan 2023
    Posts: 165
    Likes: 57, Points: 28
    Location: Palm Beach

    Darkzillicon Senior Member

    Assuming that you checked the basics like impeller. I would see if you can do a flow rate check with bucket of water or something. Like how many gallons per minute of flow you're getting. Its possible that your internal cooling passages could be clogged with bits of old impeller or some sand or mollusks or something. Probably a spec for how much waterflow you SHOULD be getting and compare that to what you're actually getting.
     
  14. DogCavalry
    Joined: Sep 2019
    Posts: 3,347
    Likes: 1,687, Points: 113
    Location: Vancouver bc

    DogCavalry Senior Member

    Gotcha. Perplexing that the engine isn't actually hot though. 189/87° is well within range.
     

  15. Darkzillicon
    Joined: Jan 2023
    Posts: 165
    Likes: 57, Points: 28
    Location: Palm Beach

    Darkzillicon Senior Member

    Do you know if you’re running the latest software on the engine, I know that there were issues with false overheat alarms.

    I would also get a cheap temperature laser gun and shoot the engine and verify it with what the computers reporting is the actual temperature of the motor.

    I think the computer has a starboard and port temperature sensor for coolant.

    also from the service manual:

    “Install correct test propeller and place outboard in a test tank or in the water. Start outboard and run at 3000 RPM in FORWARD gear for at least five minutes. Reduce outboard speed and run engine at IDLE for five minutes. Check IDLE operating temperature. Increase outboard speed to 5000 RPM. At 5000 RPM, operating temperature must not exceed 160°F (71°C). Check temperature on both sides of power head. If engine temperature is not within this range, troubleshoot cooling system. Remember, running out boards at high speeds in test tanks may disrupt water flow to water intakes of the gear case. Make sure the outboard has adequate water flow.”
     
    DogCavalry likes this.
Loading...
Similar Threads
  1. Darkzillicon
    Replies:
    160
    Views:
    20,469
  2. Dillusion
    Replies:
    7
    Views:
    1,773
  3. Tungsten
    Replies:
    26
    Views:
    3,459
  4. valvebounce
    Replies:
    3
    Views:
    2,535
  5. Runhammar
    Replies:
    17
    Views:
    1,977
  6. fallguy
    Replies:
    4
    Views:
    1,453
  7. massandspace
    Replies:
    5
    Views:
    2,456
  8. fredrosse
    Replies:
    5
    Views:
    1,717
  9. Tiger51
    Replies:
    15
    Views:
    3,885
  10. cy fishburn
    Replies:
    5
    Views:
    2,344
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.