Results 1 to 9 of 9

Thread: What is the highest RPM for SBC 400

  1. #1
    Member JUNIOR BUILDER
    Join Date
    Sep 2007
    Location
    Tacoma, WA
    Posts
    79

    What is the highest RPM for SBC 400

    I am trying to decide what gear ratio to go with but i dont want to be at max rpm at half track. What is the max rpm that i should think about going so as not to do any damage to the engine?
    68' Chevy Camaro

  2. #2
    Senior Member DYNO TECH
    Join Date
    Feb 2004
    Location
    Leonard, Texas
    Posts
    414
    Depends on how the engine is built and what components you used. Give some specifics.
    'A government big enough to give you everything you want, is big enough to take away everything you have.'

    Thomas Jefferson


    http://www.adinms.com/sitebuildercon...junkresize.jpg

  3. #3
    Senior Member DYNO OPERATOR
    Join Date
    Mar 2007
    Location
    Texas
    Posts
    525
    How tall a tire do you have on the back. 26" / 28"
    1/8th or 1/4 mile track
    Wesley
    60' 1.30
    5.58 @ 127.89

  4. #4
    Senior Member DYNO TECH
    Join Date
    Feb 2004
    Location
    Leonard, Texas
    Posts
    414
    Have you had it dynoed to see what RPM max HP and torgue ocurr? Otherwise it will just be an educated or maybe an undeucated guess. :lol: :lol: :lol: :wink:
    'A government big enough to give you everything you want, is big enough to take away everything you have.'

    Thomas Jefferson


    http://www.adinms.com/sitebuildercon...junkresize.jpg

  5. #5
    Member JOURNEYMAN
    Join Date
    May 2007
    Location
    San Dog
    Posts
    34
    Like blittle said, depends on how you build it. I had one in high school with stock 2 bolt bottom. Turned it to 6000 all the time with no problems. Now that I'm older and hopefully wiser I would use splayed caps on a 2-bolt block with the lightest rotating assembly I could afford. 400s are somewhat underrated, build it right and it will throw down solid big block numbers.
    "Good people sleep peacefully in their beds at night, only because rough men stand ready to do violence on their behalf."

  6. #6
    Member JUNIOR BUILDER
    Join Date
    Aug 2007
    Location
    Bedford, Ohio
    Posts
    86
    Building 2 400s right now, setting for 8K rpm max. But one of them I'm using a 3.625 stroke so it'll prolly still be pulling hard at 8K. Other than stroke, building them the same. Using 208 int, having ported now with a super victor.

  7. #7
    Senior Member DYNO TECH
    Join Date
    Aug 2007
    Location
    Colebrook Connecticut
    Posts
    425
    the biggest problem with 400s is the weak webbing in the block.
    I had my mains splayed and installed a crank girdle.

  8. #8
    Senior Member DYNO TECH
    Join Date
    Feb 2004
    Location
    Leonard, Texas
    Posts
    414
    Short stock 5.585 rod length is bad if you intend to turn any significant RPM over 6500. Puts to much side load on the cylinder walls. Longer rod is better.
    'A government big enough to give you everything you want, is big enough to take away everything you have.'

    Thomas Jefferson


    http://www.adinms.com/sitebuildercon...junkresize.jpg

  9. #9
    Member JUNIOR BUILDER
    Join Date
    Aug 2007
    Location
    Bedford, Ohio
    Posts
    86
    I'll be running 6"er rods, will help with detonation. Mine are 2 bold main conversions (4 bolt billet splayed caps)


Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Copyright © 2005-2016 RacingJunk.com All Rights Reserved.

Designated trademarks and brands are the property of their respective owners. Use of this Web site constitutes acceptance of the RacingJunk.com
Terms of Use, Classifieds Disclaimer, Privacy Policy, and Cookie Policy