5.7 flywheel questioin

Discussion in 'Gas Engines' started by jake100, Dec 23, 2013.

  1. jake100
    Joined: Dec 2013
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    jake100 New Member

    I recently got this boat with 5.7 chev engine I pulled the eng and found that it has a auto type flexplate for flywheel is this correct?????:confused:

  2. gonzo
    Joined: Aug 2002
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    gonzo Senior Member

    No. It should be a thick flywheel. Some couplers do have a flex plate with springs though. Can you post a photo?
  3. PAR
    Joined: Nov 2003
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    PAR Yacht Designer/Builder

    Yeah, it depends on the setup. What drive are you running?
  4. Barry
    Joined: Mar 2002
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    Barry Senior Member

    A flywheel is not required on an engine that does not have a manual transmission that would require another surface for the clutch plate to mate to.

    Many, if not all, 350 engines are internally balanced engines, either by drilling the counterweights on the crankshaft or installing a weight in the dampener at the front of the engine.

    The purpose of the flex plate in a marine application is to provide the gears for the starter motor to engage

    All the motors that we used when installing jet pumps only used a flex plate

    The flex plate might also have a weight attached near the gear teeth for balancing as well

  5. PAR
    Joined: Nov 2003
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    PAR Yacht Designer/Builder

    All the first gen 350's where internally balanced. In the late 80's (1987 I think) the first gen received an series of upgrades and became externally balanced. This ran until the Vortex castings appeared in '96.

    This said you can have it both ways (internal or external) in terms of balance. The flex plate is one of two ways to provide a starter gear ring as Barry mentioned. The simple answer is if the engine has centerline valve cover bolts, it's externally balanced. If it has perimeter valve cover bolts, it's internal. There are lots of other clues, such as the flex plate it's self which will have a weighted boss at it's center on an external balance engine. Other stuff like no mechanical fuel pump boss and certain casting marks, will clue you in on which she is.
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