Engine Mounts

Discussion in 'Inboards' started by Norvin, Jun 20, 2021.

  1. Norvin
    Joined: Jun 2021
    Posts: 1
    Likes: 0, Points: 1
    Location: Cardif

    Norvin New Member

    Hi all, I was looking at a steel Colvic Watson and found the Diesel Perkins engine was bolted direct to the hull no rubber mounts.
    My question was is that normal as one would have thought a little flexibility would be needed, it seems odd to have a solid mounting.
    Any thoughts would be appreciated.
  2. kapnD
    Joined: Jan 2003
    Posts: 1,139
    Likes: 295, Points: 83, Legacy Rep: 40
    Location: hawaii, usa

    kapnD Senior Member

    If it’s a 6 cylinder motor, vibration should be minimal except possibly at low idle.
    A 4 cylinder model will most likely shake your bones at anything below top speed!
    Heavy built boats absorb vibrations better than light ones, I’m not familiar with the build of a Colvin.
    The advantage of hard mounting is that the engine to shaft alignment can be reduced to darn near zero, and will stay that way regardless of torque loading.
  3. Barry
    Joined: Mar 2002
    Posts: 1,753
    Likes: 437, Points: 83, Legacy Rep: 158

    Barry Senior Member

    How is the prop shaft stabilized. Ie one cutlass and a flexible shaft log. Or?
    And what is the coupling style rigid or flexible?

  4. bajansailor
    Joined: Oct 2007
    Posts: 3,278
    Likes: 1,311, Points: 113, Legacy Rep: 37
    Location: Barbados

    bajansailor Marine Surveyor

    Welcome to the Forum Norvin.
    There are no steel 'Colvic Watsons' as such - they are all fibreglass.
    Can you post a photo (or 2) of your boat please?
    Do you know who designed her?
    I have seen a few straight 6 diesel engines in fibreglass fishing boats here that are bolted directly to the beds, with no mounts as such.
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.