Register now to get rid of these ads!

Black Knight's new motor

Discussion in 'HA/GR' started by blackknight, Jun 21, 2009.

  1. blackknight
    Joined: Jun 22, 2007
    Posts: 45

    blackknight
    Member

    hey all , the link below is a video of the new motor in Black Thunder.
    It's a 286ci flathead cant wait to give it a run down the 1/4 to see what times it dose. we have also upgraded the diff to a ford 9' with 5.0 ratio (we got sick of braking diff's)

    http://www.youtube.com/watch?v=IswFZrlZOEo
     
  2. bobw
    Joined: Mar 24, 2006
    Posts: 2,372

    bobw
    Member

    It sounds great! Too bad you don't have a real long driveway fro Test & Tune. What do you figure for RPM's at the top end with the 5.0 gear?
     
  3. sorry, I don't think that video illustrates how loud and cranky that engine is... I trust you've ordered some more L78's as I think you'll be chewing them up real quick:D 5:1 gears are going to be a handful down low, and a RPM cruncher at the other end... why not a 4.11?, that engine's got enough torque for a quick/fun 3.8 which will still be hard enough for you to stay above the 13.5 line...?

    The chevy sounds sweet, although you're going to have to hope you're wheelstanding the entire track:D

    Cheers,

    Drewfus:)
     
  4. blackknight
    Joined: Jun 22, 2007
    Posts: 45

    blackknight
    Member

    bob w,
    with a lot of testing with the old motor(bout 200 run's) we found that when we had 4.11 gears we did bout 4200 across the line in top gear we then when to 4.8 gears and did bout 4800
    . i was told that u need to be crossing the line in top gear at max rpm at max power . so with that being said max power is bout 4800 for that motor so the 5.0 gears will give me bout 5000 across the line in top gear so achiving max power just before the line .5000rpm is still ok for this motor it go's to 6000 with easier.

    drewfus,
    the 13.5 limit . with the old stock motor we were running it was doing 13.6's i will be running the new motor once(1 run) to see what it can do at a test and tune then we will be putting a throttle stop on it or might put the old motor back in that will do 13.5 with the new diff ratio
     
    Last edited: Jun 22, 2009

  5. not busting ya chops, love it, ya just got to find a car to put that engine in for DOTD-10;):D

    Cheers,

    Drewfus
     
  6. flatty slapper 67
    Joined: Nov 10, 2008
    Posts: 25

    flatty slapper 67
    Member

    [​IMG]What we had in the old diff was -with 4.11 ratio -4200 at the line and then with
    the 4,8- jeff went to 4800 at line and still had about 350 in hand.-13.65
    the new engine runs peak hp at 4800 and has only a minute reduction in hp and
    tqe and runs well at 5600 and on dyno still has some space to go from there.
     
    Last edited: Jun 22, 2009
  7. blackknight
    Joined: Jun 22, 2007
    Posts: 45

    blackknight
    Member

    ya dotd- 10 cant wait.i wish center steer car's where allowed for the quickest flathead .

    where off to gunnadah in a few weeks will post some times from the 1/8 of the new motor
     

Share This Page

Register now to get rid of these ads!

Archive

Copyright © 1995-2021 The Jalopy Journal: Steal our stuff, we'll kick your teeth in. Terms of Service. Privacy Policy.

Atomic Industry
Forum software by XenForo™ ©2010-2014 XenForo Ltd.