Propulsion

Discuss marine engines, drives, and propulsion systems.

  1. Props

    Propeller selection, performance comparison, prediction, experience, and modification.
    Discussions:
    543
    Messages:
    6,436
    Latest: Seeking Input for DIY Propeller Cleaning Tool – Master's Thesis Research Survey gonzo, Apr 29, 2025
    RSS

  2. Surface Drives

    Surface Drives. Arneson, BPM, Seafury, PSI, Levi, Etc.
    Discussions:
    186
    Messages:
    2,864
    Latest: Is Levi Drives still in business? BlueBell, May 30, 2025
    RSS

  3. Jet Drives

    Jet Drives (pumps, impellers, etc.)
    Discussions:
    463
    Messages:
    4,452
    Latest: drive for landing craft used on both ocean and rivers DogCavalry, Feb 10, 2025
    RSS

  4. Outboards

    2-stroke and 4-stroke outboard motors.
    Discussions:
    1,044
    Messages:
    10,061
    Latest: OXE Diesel Outboard Experiences? comfisherman, Jun 2, 2025
    RSS

  5. Sterndrives

    Stern drive lower and upper units, transom and gimbal assemblies, steering, and trim pumps. Mercruiser (Alpha One, Alpha One Generation II, Alpha SS, Bravo One, Bravo Two, Bravo Three, Bravo XR Sportmaster, TRS, Speed Master), IMCO, ILMOR, Konrad, OMC, Volvo Penta
    Discussions:
    549
    Messages:
    3,839
    Latest: Stern Powr Parts Laurence Bellamy, Aug 3, 2024
    RSS

  6. Pod Drives

    Volvo IPS, ZF, CMD Zeus, and other pod-drive systems
    Discussions:
    29
    Messages:
    299
    Latest: 50-200 hp electric pod with nozzle and motor on hub? ram68ocean, Jul 5, 2021
    RSS

  7. Inboards

    Inboard and Vee-drive hardware: struts, stuffing boxes, transmissions, coolers
    Discussions:
    540
    Messages:
    5,009
    Latest: Velvet Drive CR2 drop center gear. Carteret, Jun 21, 2025
    RSS

  8. Diesel Engines

    Diesel Engines
    Discussions:
    691
    Messages:
    8,624
    Latest: 38' 1984 posillipo technema with Fiat Iveco diesel engines question comfisherman, Jun 6, 2025
    RSS

  9. Gas Engines

    Gasoline Engines
    Discussions:
    423
    Messages:
    4,652
    Latest: Anyone need a torque monster 383 SBC? gonzo, Sep 24, 2024
    RSS

  10. Electric Propulsion

    Electric propulsion systems
    Discussions:
    106
    Messages:
    2,119
    Latest: Sizing a propeller to match an electric motor gonzo, Jun 10, 2025
    RSS

  11. Hybrid

    Hybrid propulsion such as diesel electric, hydraulic.
    Discussions:
    211
    Messages:
    5,275
    Latest: Hydraulic Drive for max efficiency Rumars, May 6, 2025
    RSS

  12. DIY Marinizing

    A forum to discuss "do it yourself" marinizing of engines / conversion of automotive engines to marine use.
    Discussions:
    276
    Messages:
    5,577
    Latest: VW/AUDI 3.0TDI marinising Skravo, Aug 18, 2024
    RSS
Page 1 of 25
Sort By:
Title Start Date
Replies Views ↓
Last Message
  1. friedlbug

    To those who want to convert a weed eater...

    friedlbug, Jun 30, 2004 ... 2 3
    Replies:
    35
    Views:
    204,123
    thudpucker
    May 14, 2012
  2. Guillermo

    New propulsion sytems for ships

    Guillermo, Dec 2, 2005 ... 37 38 39
    Replies:
    579
    Views:
    195,818
    fredrosse
    Oct 8, 2023
  3. Guest625101138

    DDWFTTW - Directly Downwind Faster Than The Wind

    Guest625101138, Jan 4, 2009 ... 38 39 40
    Replies:
    588
    Views:
    145,903
    gonzo
    Oct 4, 2021
  4. brian eiland

    Exciting New EPS Thruster (& Propulsion)

    brian eiland, Nov 16, 2005 ... 4 5 6
    Replies:
    86
    Views:
    108,527
    johnnydfred
    Jan 9, 2025
  5. kenstl17

    jet drive for small river fishing

    kenstl17, Dec 21, 2004 ... 2
    Replies:
    20
    Views:
    97,982
    homebuilt
    Jan 19, 2009
  6. MrLknowles2

    Homemade Outboard (Electric) - Help!

    MrLknowles2, Jul 26, 2012
    Replies:
    14
    Views:
    97,499
    boatindad
    Apr 25, 2014
  7. glines

    Electric Jet Ski Conversion

    glines, Apr 26, 2005 ... 2 3
    Replies:
    44
    Views:
    85,619
    sparky_wap
    Jul 17, 2010
  8. tom kane

    Define what a Surface-Piercing propeller is

    tom kane, Jul 12, 2009 ... 13 14 15
    Replies:
    212
    Views:
    84,413
    tom kane
    Feb 18, 2021
  9. brian eiland

    Gas from Water, (WaterFuel), HHO technology

    brian eiland, May 15, 2006 ... 17 18 19
    Replies:
    278
    Views:
    80,972
    masrapido
    Apr 2, 2014
  10. EvilMoose

    Engine swap: what is possible?

    EvilMoose, Feb 24, 2004
    Replies:
    12
    Views:
    78,165
    gonzo
    Jun 9, 2008
  11. Mat-C

    Convert kN to required kW

    Mat-C, Mar 1, 2012 ... 2
    Replies:
    15
    Views:
    67,168
    powerabout
    Mar 21, 2012
  12. Guest

    Diesel outboards and jetboat engines coming

    Guest, Oct 9, 2002 ... 2 3
    Replies:
    39
    Views:
    62,938
    foilcats
    Apr 1, 2007
  13. brian eiland

    in-line 6 Cylinder Engines, 'straight-six'

    brian eiland, Jun 26, 2012 ... 6 7 8
    Replies:
    111
    Views:
    62,480
    Frosty
    Oct 11, 2012
  14. sigurd

    Boiler design and Green Steam Engine

    sigurd, Mar 5, 2009 ... 2 3
    Replies:
    36
    Views:
    61,969
    Questor
    Sep 16, 2010
  15. srimes

    tiny trolling motor for kayak/canoe fishing

    srimes, Oct 1, 2008
    Replies:
    13
    Views:
    61,771
    sparky_wap
    Jan 2, 2009
  16. SudorracMechEng

    wiggle drive propulsion application

    SudorracMechEng, May 7, 2012 ... 19 20 21
    Replies:
    304
    Views:
    57,921
    swashdrive
    Aug 17, 2012
  17. ChillrMn1

    Quadrajet Adjustment

    ChillrMn1, Dec 8, 2004 ... 2 3 4
    Replies:
    53
    Views:
    52,828
    maresca
    Jun 25, 2006
  18. ldrumond

    Use pressurized water as manuevering thruster?

    ldrumond, Jun 18, 2006 ... 6 7 8
    Replies:
    109
    Views:
    46,167
    SeaJay
    Aug 8, 2009
  19. justinDesign

    Do they exist? articulating paddle wheel

    justinDesign, Sep 24, 2007 ... 2
    Replies:
    27
    Views:
    43,249
    Jimbo1490
    Feb 1, 2009
  20. yipster

    dual prop shaft ?

    yipster, Oct 30, 2002 ... 2 3
    Replies:
    34
    Views:
    42,842
    Christian Lucas
    May 17, 2021
  21. Kalagan

    (Newbie) why don't Boats use Multi-Gear Transmissions?

    Kalagan, May 8, 2009 ... 2
    Replies:
    22
    Views:
    41,376
    powerabout
    Dec 2, 2009
  22. CatBuilder

    Ganging Outboards - Does it work?

    CatBuilder, Jan 14, 2012 ... 11 12 13
    Replies:
    183
    Views:
    41,203
    DCockey
    Jul 19, 2013
  23. brian eiland

    FLYWHEEL Energy Storage Systems

    brian eiland, Apr 21, 2010 ... 3 4 5
    Replies:
    69
    Views:
    40,617
    brian eiland
    Nov 16, 2020
  24. Fanie

    Continuously Variable Transmissions

    Fanie, Jul 30, 2009 ... 10 11 12
    Replies:
    166
    Views:
    39,882
    BATAAN
    Jan 12, 2012
  25. DennisRB

    Diesel VS 4 stroke outboard fuel consumption

    DennisRB, Jul 20, 2010 ... 5 6 7
    Replies:
    100
    Views:
    39,881
    FAST FRED
    Sep 24, 2010
  26. roatan diver

    Do you really need a short shaft on an inflatable?

    roatan diver, Sep 24, 2010
    Replies:
    10
    Views:
    37,783
    Easy Rider
    Oct 5, 2010
  27. Fanie

    Water Pump as a Jet Drive

    Fanie, Dec 8, 2010 ... 2
    Replies:
    18
    Views:
    36,800
    anthony goodson
    Jan 20, 2011
  28. Willallison

    Trolling valves

    Willallison, Feb 13, 2003 ... 2
    Replies:
    17
    Views:
    35,906
    Willallison
    Feb 27, 2003
  29. CatBuilder

    How Much Does it Cost to Marinize a Kubota?

    CatBuilder, Feb 3, 2012 ... 2 3 4
    Replies:
    57
    Views:
    35,657
    FAST FRED
    Feb 29, 2012
  30. fredrosse

    Steam Paddlewheel Boat

    fredrosse, Jan 25, 2005 ... 2
    Replies:
    24
    Views:
    34,621
    phrogjlf@yahoo
    Dec 17, 2014
  31. Kalagan

    best propolution method, normal Prop, Jet style or paddle wheel?

    Kalagan, Nov 5, 2009 ... 2
    Replies:
    20
    Views:
    34,435
    Boston
    Mar 14, 2010
  32. kalel76

    Why is my gas gauge stuck on E? (pics)

    kalel76, May 2, 2007
    Replies:
    4
    Views:
    34,090
    Frosty
    May 4, 2007
  33. jxing62

    airboat propulsion and drive

    jxing62, May 24, 2007 ... 2 3
    Replies:
    40
    Views:
    33,875
    COLD-EH'
    May 31, 2007
  34. Boston

    these turbine alternaters are easy to make

    Boston, Apr 1, 2009 ... 8 9 10
    Replies:
    143
    Views:
    32,999
    Boston
    Nov 16, 2010
  35. YK GEO

    Shallow Water Tunnel Design

    YK GEO, Oct 5, 2009 ... 2
    Replies:
    22
    Views:
    32,871
    FAST FRED
    Nov 11, 2009
  36. Boston

    the steamless steam engine

    Boston, Apr 30, 2009 ... 3 4 5
    Replies:
    73
    Views:
    32,569
    cthippo
    Feb 8, 2011
  37. JaredT

    most efficient propulsion?

    JaredT, Aug 2, 2008 ... 2 3
    Replies:
    34
    Views:
    32,481
    Guest625101138
    Apr 17, 2009
  38. dockdave

    Marine propane gas conversion

    dockdave, Jan 11, 2009 ... 2
    Replies:
    18
    Views:
    32,127
    CDK
    Jan 14, 2009
  39. yipster

    HP to WATT to THRUST

    yipster, Feb 17, 2005 ... 2
    Replies:
    21
    Views:
    29,705
    yipster
    Jun 6, 2005
  40. CatBuilder
    Locked

    Brainstorming Retractable Drives

    CatBuilder, Sep 29, 2011 ... 3 4 5
    Replies:
    64
    Views:
    29,546
    brian eiland
    Jul 29, 2012
Showing threads 1 to 40 of 985

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