Propulsion

Discuss marine engines, drives, and propulsion systems.

  1. Props

    Propeller selection, performance comparison, prediction, experience, and modification.
    Discussions:
    543
    Messages:
    6,440
    Latest: The mystery of a proper prop and terrible performance sdowney717, Jul 22, 2025
    RSS

  2. Surface Drives

    Surface Drives. Arneson, BPM, Seafury, PSI, Levi, Etc.
    Discussions:
    186
    Messages:
    2,866
    Latest: 8 ft model boat needing surface drive options portacruise, Dec 3, 2025
    RSS

  3. Jet Drives

    Jet Drives (pumps, impellers, etc.)
    Discussions:
    464
    Messages:
    4,474
    Latest: Affordable Water Jets? RSD, Sep 1, 2025
    RSS

  4. Outboards

    2-stroke and 4-stroke outboard motors.
    Discussions:
    1,050
    Messages:
    10,195
    Latest: What is this heckin part? DogCavalry, Dec 5, 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:
    552
    Messages:
    3,882
    Latest: Mercruiser Alpha 1 gen 2 gonzo, Oct 11, 2025
    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:
    5,027
    Latest: Prop Shaft Systems. brian eiland, Dec 8, 2025
    RSS

  8. Diesel Engines

    Diesel Engines
    Discussions:
    695
    Messages:
    8,701
    Latest: Efficiency vs Effectiveness A L F, Dec 13, 2025 at 3:36 AM
    RSS

  9. Gas Engines

    Gasoline Engines
    Discussions:
    424
    Messages:
    4,654
    Latest: How to Measure the Timing Chain-VOLVO engine 5.7GXI gonzo, Nov 19, 2025
    RSS

  10. Electric Propulsion

    Electric propulsion systems
    Discussions:
    111
    Messages:
    2,190
    Latest: Greenline 33 All electric -Norway Adventure MotorCityBW, Dec 8, 2025
    RSS

  11. Hybrid

    Hybrid propulsion such as diesel electric, hydraulic.
    Discussions:
    212
    Messages:
    5,294
    Latest: Real Hybrid fallguy, Nov 29, 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:
    5,578
    Latest: VW/AUDI 3.0TDI marinising Radu Druncea, Jul 2, 2025
    RSS
Page 3 of 25
Sort By:
Title Start Date
Replies Views
Last Message ↓
  1. captainralph

    DIY Gas Sep Combo

    captainralph, Dec 23, 2018
    Replies:
    2
    Views:
    2,498
    captainralph
    Dec 24, 2018
  2. Brian.Lin

    tug boat engine mounts design (rigid? or flexible?)

    Brian.Lin, Nov 16, 2018
    Replies:
    13
    Views:
    4,241
    Ad Hoc
    Nov 20, 2018
  3. Afilimon

    How to select motors for catamaran?

    Afilimon, Nov 4, 2018 ... 2
    Replies:
    16
    Views:
    5,796
    gonzo
    Nov 8, 2018
  4. DCockey

    Raw seawater as only fuel claim

    DCockey, Sep 28, 2018
    Replies:
    8
    Views:
    3,319
    Blueknarr
    Sep 29, 2018
  5. Archangl7

    electric golf cart inboard design, need help!

    Archangl7, Sep 4, 2018
    Replies:
    7
    Views:
    5,012
    Archangl7
    Sep 13, 2018
  6. ocean dreamer

    Yachting propulsion systems

    ocean dreamer, Sep 2, 2018
    Replies:
    4
    Views:
    2,751
    JamesG123
    Sep 2, 2018
  7. crwsound

    Velvet Drive: How to Separate Reduction Housing from Gearbox?

    crwsound, Aug 5, 2018
    Replies:
    9
    Views:
    7,447
    MikeJohns
    Aug 7, 2018
  8. James007

    convert inboard to outboard

    James007, Nov 20, 2008
    Replies:
    6
    Views:
    10,419
    Butch
    Jul 11, 2018
  9. sdowney717

    Jabsco 4528 impeller pin, does it push or thread in

    sdowney717, Jul 3, 2018
    Replies:
    2
    Views:
    2,247
    sdowney717
    Jul 7, 2018
  10. 5teve

    Muffler Drains

    5teve, Mar 7, 2018
    Replies:
    9
    Views:
    3,804
    5teve
    Jun 25, 2018
  11. Israel

    Bayliner 2.3 turbo

    Israel, May 26, 2018
    Replies:
    10
    Views:
    3,858
    Israel
    May 30, 2018
  12. DSTONE

    OMC-Ford 2.3 trouble

    DSTONE, Aug 9, 2005
    Replies:
    4
    Views:
    14,335
    Israel
    May 26, 2018
  13. Tlray

    Water in the cylinders 4.3

    Tlray, May 19, 2018 ... 2
    Replies:
    15
    Views:
    14,029
    PAR
    May 22, 2018
  14. Upston

    Transmission ratios

    Upston, May 16, 2018
    Replies:
    2
    Views:
    2,550
    Upston
    May 21, 2018
  15. franklou

    motor and waterjet model

    franklou, Apr 17, 2018
    Replies:
    7
    Views:
    3,899
    franklou
    Apr 18, 2018
  16. PickleRick

    A little boat and a simple diesel project

    PickleRick, Dec 4, 2017
    Replies:
    5
    Views:
    3,470
    gonzo
    Mar 12, 2018
  17. xellz

    Saildrive or shaft with electric motor

    xellz, Feb 10, 2018
    Replies:
    2
    Views:
    5,156
    xellz
    Feb 11, 2018
  18. Singleinboard

    1973 Silverton Replace V Drive

    Singleinboard, Jan 8, 2018
    Replies:
    3
    Views:
    4,849
    PAR
    Jan 9, 2018
  19. 91SARATH

    Propeller design

    91SARATH, Dec 14, 2017 ... 2
    Replies:
    27
    Views:
    9,818
    gonzo
    Dec 19, 2017
  20. Archangl7

    electric motor outboard conversion

    Archangl7, Aug 5, 2017 ... 2
    Replies:
    16
    Views:
    12,937
    HMLee
    Dec 1, 2017
  21. xellz

    Advice on shaft, seal, bearings for wooden kayak

    xellz, Nov 26, 2017
    Replies:
    8
    Views:
    4,506
    xellz
    Nov 29, 2017
  22. Carter Beall

    electric hydrofoil

    Carter Beall, Jun 27, 2016
    Replies:
    10
    Views:
    7,994
    Ian Brown
    Aug 21, 2017
  23. kschung

    propulsion of kort nozzle

    kschung, Aug 10, 2004
    Replies:
    11
    Views:
    13,255
    Barry
    Aug 13, 2017
  24. Leveboat

    reverberation on pontoon?

    Leveboat, Apr 23, 2017 ... 2
    Replies:
    16
    Views:
    4,870
    ondarvr
    Apr 25, 2017
  25. ATMHC

    "Duo-Prop" Inboard Transmission ????

    ATMHC, Jun 26, 2007
    Replies:
    8
    Views:
    7,061
    brian eiland
    Apr 23, 2017
  26. Angle X

    GM 3.6 motor in boat?

    Angle X, Apr 23, 2017
    Replies:
    0
    Views:
    3,743
    Angle X
    Apr 23, 2017
  27. valvebounce

    jack plates and steering connection.

    valvebounce, Apr 17, 2017
    Replies:
    2
    Views:
    3,072
    valvebounce
    Apr 18, 2017
  28. Squidly-Diddly

    homebrew and bottling of hydrogen gas with scuba compressor?

    Squidly-Diddly, Apr 9, 2017
    Replies:
    7
    Views:
    3,718
    Stumble
    Apr 10, 2017
  29. mitchellleary

    Advice on the correct power rating for my Autonomous boat

    mitchellleary, Mar 30, 2017 ... 2
    Replies:
    20
    Views:
    6,021
    daiquiri
    Apr 7, 2017
  30. Liopleurodon

    Jet drive, tunnel, or tunnel outboard for low HP low draft

    Liopleurodon, Mar 16, 2017
    Replies:
    7
    Views:
    6,774
    Liopleurodon
    Mar 23, 2017
  31. DCockey

    Short Shaft / Surface Drive / Mud Motors

    DCockey, Mar 20, 2017
    Replies:
    1
    Views:
    5,947
    tom kane
    Mar 20, 2017
  32. 1J1

    Magnus effect for ship propulsion

    1J1, Mar 6, 2017 ... 2 3
    Replies:
    36
    Views:
    14,884
    Ilan Voyager
    Mar 14, 2017
  33. Random_user

    Used hydra-drive

    Random_user, Mar 6, 2017
    Replies:
    2
    Views:
    3,360
    Random_user
    Mar 6, 2017
  34. brian eiland

    U-joint, CV-joint, Thompson coupling

    brian eiland, Mar 16, 2007 ... 2 3
    Replies:
    37
    Views:
    28,608
    Angle X
    Mar 4, 2017
  35. bcobbett

    1995 Seadoo HX - Stalls at high speed

    bcobbett, Dec 10, 2016
    Replies:
    3
    Views:
    3,201
    Random_user
    Mar 3, 2017
  36. Timetogo

    Putting this out there for discussion (livaboard river boat propulsion)

    Timetogo, Feb 27, 2017
    Replies:
    2
    Views:
    4,002
    sailhand
    Feb 28, 2017
  37. dwicejama

    voith scheider construction

    dwicejama, Feb 22, 2017
    Replies:
    0
    Views:
    3,163
    dwicejama
    Feb 22, 2017
  38. bluedolfin

    Repower 34' yacht with diesel AC gen-set & VFD

    bluedolfin, Feb 15, 2017
    Replies:
    9
    Views:
    4,771
    Stumble
    Feb 16, 2017
  39. JasonCatt

    Interesting digital magazines on all things electric....

    JasonCatt, Feb 4, 2017
    Replies:
    1
    Views:
    2,726
    Ike
    Feb 5, 2017
  40. Angle X

    Rim drive propeller? Shaft driven rim drive?

    Angle X, Dec 31, 2016
    Replies:
    0
    Views:
    3,879
    Angle X
    Dec 31, 2016
Showing threads 81 to 120 of 993

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