vdrive d4-300 installation help

Discussion in 'Powerboats' started by bigbear69, Jan 24, 2019.

  1. bigbear69
    Joined: Aug 2008
    Posts: 32
    Likes: 0, Points: 6, Legacy Rep: 10
    Location: New Zealand

    bigbear69 Junior Member

    Hi all, Am thinking of replacing the 2 mercruiser 5.7L v8 alpha 1 legs in a bayliner 2955 with a diesel.
    Have found a volvo d4 300 and vdrive for a reasonable price and was wondering if anyone can help with the design of the install. ie shaft size/angle, prop size etc and any advice with the setup?
    Boat is around 5 tonne. not worried about top speed looking for economy and being able to cruise at 18 - 20 knots.
    my other options are single diesel with stern leg or twin diesels with stern legs.
    v drive install would be a lot more work etc but less maintenance issues as boat will be permanently in salt water.
    Any help/ advice much appreciated
  2. Barry
    Joined: Mar 2002
    Posts: 1,812
    Likes: 465, Points: 83, Legacy Rep: 158

    Barry Senior Member

    Email the actual Volvo Penta sales representative for your area. they can supply the website link to the installation.
    I had downloaded the D6 several years ago. It also included a wealth of information on ventilation requirements, fuel tank requirements, cut out sizes, mounting etc

    It was probably about 40 pages
  3. missinginaction
    Joined: Aug 2007
    Posts: 1,103
    Likes: 254, Points: 83, Legacy Rep: 512
    Location: New York

    missinginaction Senior Member

    Whoa.......If you replace a sterndrive with a v-drive how are you going to deal with those big holes you'll have in the transom? New engine mounts will be necessary Mounts for a Chevy aren't going to hold a diesel. You'll need to install a shaft log in the aft section of the boat to accept the driveshaft. That Bayliner isn't likely designed for a shaftlog as it was built to be a sterndrive. You'll need a shaft seal or stuffing box. Shaft seals are much better. You'll need a strut. Inboard Prop. How will you steer? Without the sterndrive you'll need new steering gear, a rudder, a rudder port, tiller arm.....Of course everything you do needs to be precisely aligned so that it all works. Your new drive system will require new and different wiring, plumbing, fuel lines. What about mufflers? How will you handle the exhaust? I wouldn't think of doing anything like this. I DO understand the salt water issue. I also own a v-drive boat and I'm very happy with it. My advice is to sell the Bayliner and find yourself a good v-drive or inboard boat. If you want a diesel, that's all well and good. Find a diesel boat that was designed as a diesel from the factory, as an inboard or a v-drive. Have a survey done and know what you are getting into. I'm not throwing cold water on you, I'm just trying to save you some wasted time and energy, and frustration.
    Last edited: Jan 26, 2019
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