Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE t-shirt and membership sticker when you sign up for a Premium Membership and choose the recurring plan.

What exactly is "externally balanced"?

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by derek2002, Oct 25, 2000.

  1. derek2002

    derek2002 1/2 ton status

    Joined:
    Aug 1, 2000
    Posts:
    247
    Likes Received:
    0
    Location:
    Midland, Michigan USA
    What exactly is \"externally balanced\"?

    I am aware that my bbc 454 has an externally balanced flywheel and the 350's is internally balanced. So, I just figured that all bbc are externally balanced and sbc are internally balanced. However, a kid was telling me today how his 427 bb was internally balanced. So, whats the deal? What is the difference btwn a flywheel that is internally and externally balanced? Thanks for the info.

    Later,

    -Derek
    1977 3/4 Ton & Blazer Project (Body Needed)
    http://www.4chevy.com
     
  2. Jeff427

    Jeff427 1/2 ton status

    Joined:
    May 22, 2000
    Posts:
    1,186
    Likes Received:
    0
    Location:
    Gladwin, MI
    Re: What exactly is \"externally balanced\"?

    Externally balanced flywheels, have weights on them to compensate for the crankshaft being out of balance. 454 BB and 400 SB are externally balanced the rest of the BB and SB Chevrolet motors are internally balanced.

    BTW Derek2002, did you get my email? Haven't heard from you yet, just curious.

    Jeff427
    <font color=red>Mud Dog Off Road Club</font color=red>
    http://muddogoffroad.coloradok5.com
     
  3. rich'90

    rich'90 1/2 ton status

    Joined:
    Feb 27, 2000
    Posts:
    159
    Likes Received:
    0
    Location:
    Savannah, GA
    Re: What exactly is \"externally balanced\"?

    You forgot 383 stroker, since it has a 400 crank.

    Go heavy or Go home[​IMG]
     
  4. derek2002

    derek2002 1/2 ton status

    Joined:
    Aug 1, 2000
    Posts:
    247
    Likes Received:
    0
    Location:
    Midland, Michigan USA
    Re: What exactly is \"externally balanced\"?

    So is there an advantage to a motor being internally/externally balanced compared to the other? Jeff- I sent you a private message.

    Later,

    -Derek
    1977 3/4 Ton & Blazer Project (Body Needed)
    http://www.4chevy.com
     
  5. Jeff427

    Jeff427 1/2 ton status

    Joined:
    May 22, 2000
    Posts:
    1,186
    Likes Received:
    0
    Location:
    Gladwin, MI
    Re: What exactly is \"externally balanced\"?

    Derek2002, there is really no advantage or disadvantage for street (or trail) use. If you were building a top fuel dragster, then I would say that you would want your 454 balanced internally. So as long as you have the right flywheel, and harmonic balancer, you will have nothing to worry about. Most Do*g* and Fo*d motors are externally balanced, not that thats reassuring, but it is fairly common.

    Yes 383s (350 bored 0.30 over with a 400 crank) are externally balanced, because they use a 400 crank, forgot about them because they aren't production motors.

    Jeff427
    <font color=red>Mud Dog Off Road Club</font color=red>
    http://muddogoffroad.coloradok5.com
     

Share This Page