BBC to berkely jet pump water hose plumbing configurations

Discussion in 'Jet Drives' started by racetucker1, Jun 6, 2011.

  1. racetucker1
    Joined: Jun 2011
    Posts: 1
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: portland,oregon

    racetucker1 New Member

    I have a 454 BBC using a 1981 Berkeley jet pump drive.
    I have had 5 boats and this is my first jet boat.
    I have rebuilt this and would like to know the correct water hose plumbing configuration.
    Is the water fed from the jet pump.. to each exhaust at 1 of the 2 front water ports?
    Then from the other front water port to where a engine water pump would be?
    Then out the thermostat housing back to the rear water port on the exhaust manifolds?
    Does anyone have a diagram or can you explain it to me?
    I am
    Thank you for this forum.
  2. jim lee
    Joined: Feb 2007
    Posts: 368
    Likes: 20, Points: 18, Legacy Rep: 247
    Location: Anacortes, WA

    jim lee Senior Member

    You have it pretty much correct. Water goes from pump, through a valve, into the exhaust "logs" to preheat, from there into front of engine, out thermostat port through the "snails" on the end of the exhaust "logs".

    Now, do NOT put in a thermostat. Not even one of them fancy jet boat bypass ones. The normal automotive ones will blow the cooling water through all your gaskets, the jet boat ones can eventually lead to cracked heads.

    How to adjust jet boat cooling: Remember the valve, gate or ball, between the pump and the logs? This is your adjustment. Open it up and idle your motor in the lake. Set it at idle as hot as you are comfortable with. Once you are happy with you idle temp, you are done. When you mash the gas, the engine will get a lot cooler, don't worry, this is normal and won't hurt it.


    -jim lee
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.