[Question] New to Jet boats. can you use a std flex plate? bbc
+ Reply to Thread
Results 1 to 12 of 12

Thread:
New to Jet boats. can you use a std flex plate? bbc

  1. #1
    Member lethal injection's Avatar
    Join Date
    Jul 2012
    Location
    Jerseyville Il
    Posts
    76

    Default New to Jet boats. can you use a std flex plate? bbc

    do you have to use a flywheel or can you use the std flex plate that came with my rotating assembly? is it too flimsy?

  2. Remove Advertisements
    PerformanceBoats.com
    Advertisements
     

  3. #2
    Member
    Join Date
    Jan 2012
    Location
    Independence KS
    Posts
    95

    Default

    I think it depends on the rear mount your running? I am using a flexplate with a glencoe style rear mount.

  4. #3
    Member
    Join Date
    Jan 2012
    Location
    Independence KS
    Posts
    95

    Default

    Glennwood or niscon my bad

  5. Remove Advertisements
    PerformanceBoats.com
    Advertisements
     

  6. #4
    Member lethal injection's Avatar
    Join Date
    Jul 2012
    Location
    Jerseyville Il
    Posts
    76

    Default

    Quote Originally Posted by KansasJet View Post
    Glennwood or niscon my bad
    Will be using a 3 point system ..top mount starter Thanks.!

  7. #5
    Member
    Join Date
    Jan 2012
    Location
    Independence KS
    Posts
    95

    Default

    If you have a new roto assembly you will want to run what came with it. Im in process of putting in an Eagle full roto in my BBC and its exteranly balanced. If your in the same boat ( pun intended) youll want to run the flex plate. Mine is rated up to 700 hp, so its strong enough. Not sure what you have but....? A flex plate will fit a bellhousing mount with ease.

  8. #6
    Senior Member wpmxwb's Avatar
    Join Date
    Jan 2011
    Location
    Long Beach, California, United States
    Posts
    157

    Default

    It kinda depends on what the boat had in it before. If it had a flywheel in it u will need a spacer to take up the length difference so the pto reaches the pump

  9. #7
    Senior Member lilrick's Avatar
    Join Date
    Dec 2007
    Location
    Lakewood
    Posts
    1,450

    Default

    It really depends on RPM. Most jet boats live their lives under 5500 rpm and can get away with a std flexplate. More RPM, such as in a flatty would require a thicker flexplate Like CSR sells or a flywheel. I had an alum flywheel on my K boat, CSR thick flexplate on my pro stock boat, and a std flexplate on every suck boat I've had.
    And don't forget that your 454 Is probably externally balanced and will require the appropriate counterweighted flexplate.
    Last edited by lilrick; 07-12-2012 at 06:38 PM.

  10. #8
    Member lethal injection's Avatar
    Join Date
    Jul 2012
    Location
    Jerseyville Il
    Posts
    76

    Default

    Quote Originally Posted by wpmxwb View Post
    It kinda depends on what the boat had in it before. If it had a flywheel in it u will need a spacer to take up the length difference so the pto reaches the pump

    The engine is a 468 BBC with Brodix heads 10.5:1 Comp Roller Marine cam Eagle Rotating assembly yes the flywheel is rated same as yours, just didnt know about the flex factor at the starter without a converter bolted to it or anything. Thanks for all the help! i was hoping i could run it this way!!! LESS WEIGHT! YEAH!!

  11. #9
    Senior Member
    Join Date
    Dec 2007
    Location
    Newbury Park, Ca/Mohave Valley, Az
    Posts
    8,169

    Default HP rating...

    Quote Originally Posted by KansasJet View Post
    If you have a new roto assembly you will want to run what came with it. Im in process of putting in an Eagle full roto in my BBC and its exteranly balanced. If your in the same boat ( pun intended) youll want to run the flex plate. Mine is rated up to 700 hp, so its strong enough. Not sure what you have but....? A flex plate will fit a bellhousing mount with ease.
    HP ratings mean nothing in a jetboat. The drive line attaches directly to the crankshaft. The only reason you even need a flywheel/flexplate is for the starter.... Most recreational jets will never get anywhere close to "red lining" the RPMs..... I've seen 2 flywheels spit the ring gear off in a flatbottom that revved like flipping a light switch, but never hurt a flexplate in a jet....
    Ray
    LOUD BOATS SAVE LIVES

  12. #10
    Living in a cage of fear thatguy's Avatar
    Join Date
    May 2008
    Location
    Redding, CA
    Posts
    16,461

    Default

    Quote Originally Posted by lethal injection View Post
    The engine is a 468 BBC with Brodix heads 10.5:1 Comp Roller Marine cam Eagle Rotating assembly yes the flywheel is rated same as yours, just didnt know about the flex factor at the starter without a converter bolted to it or anything. Thanks for all the help! i was hoping i could run it this way!!! LESS WEIGHT! YEAH!!
    Sounds like you stole the motor from our Miller!

    I run a flexplate just fine.
    Tommy
    Quote Originally Posted by Rexone View Post
    Tommy please remove all Jimsplace quotes from your sig and don't put more back. He doesn't like it and it is against the rules. Thank you.
    "So as through a glass, and darkly
    The age long strife I see
    Where I fought in many guises,
    Many names, but always me."

    Gen. George S Patton

  13. #11
    Member lethal injection's Avatar
    Join Date
    Jul 2012
    Location
    Jerseyville Il
    Posts
    76

    Default

    Quote Originally Posted by thatguy View Post
    Sounds like you stole the motor from our Miller!

    I run a flexplate just fine.
    Thanks for all the help! last boat i built was the same hull but a stern drive new to the whole jet thing. if i can get it to 65mph id be happy!

  14. #12
    Senior Member applekrate's Avatar
    Join Date
    May 2008
    Location
    Maricopa & St Johns, Arizona
    Posts
    228

    Default

    Quote Originally Posted by lilrick View Post
    It really depends on RPM. Most jet boats live their lives under 5500 rpm and can get away with a std flexplate. More RPM, such as in a flatty would require a thicker flexplate Like CSR sells or a flywheel. I had an alum flywheel on my K boat, CSR thick flexplate on my pro stock boat, and a std flexplate on every suck boat I've had.
    And don't forget that your 454 Is probably externally balanced and will require the appropriate counterweighted flexplate.

    I'll agree on the 5,500 rpm UNDER LOAD but, they tend to buzz pretty high when they come out of the water! I know mine does anyway.
    www.pontiacheaven.org
    '72 Hondo Flat
    '74 Rogers jet
    Phil 2:11

+ Reply to Thread

Quick Reply Quick Reply

Register Now

Please enter the name by which you would like to log-in and be known on this site.

Please enter a password for your user account. Note that passwords are case-sensitive.

Please enter a valid email address for yourself.

Please select your insurance company (Optional)

Log-in


Tags for this Thread

Digg This Thread

Posting Permissions

  • You may post new threads
  • You may post replies
  • You may not post attachments
  • You may not edit your posts
  •  
 

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95