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.

SBC Head ?s

Discussion in 'The Garage' started by cwn anwyn, Mar 21, 2005.

  1. cwn anwyn

    cwn anwyn 1/2 ton status Premium Member

    Joined:
    Oct 30, 2002
    Posts:
    1,268
    Likes Received:
    6
    Location:
    Falcon CO
    I replaced a blown head gasket(or cracked head) with one I got from a guy on colorado4x4. I would have put both of his on but one of the valves is messed up. I had good compression on the other side. So I slapped the one head on. The only difference in the casting numbers is the new one is an X. +10cc on the intake. Will running one X head and one normal head affect anything. Its only temporary till I can get both heads redone. Any info would be great. Thanks

    Z:grin:
     
  2. 1979jimmy350

    1979jimmy350 1/2 ton status

    Joined:
    Mar 24, 2004
    Posts:
    3,069
    Likes Received:
    0
    Location:
    Ann Arbor Mi
    not having the same compression ratio will cause your engine to be more unbalanced and make uneven power. you would have to run the numbers to get the comprssion ratios and what the difference is. A small amount of difference should not be to bad.
     
  3. cwn anwyn

    cwn anwyn 1/2 ton status Premium Member

    Joined:
    Oct 30, 2002
    Posts:
    1,268
    Likes Received:
    6
    Location:
    Falcon CO
    Hey thanks for the input. I dont think it will be a big difference if any on the compression ratio's.

    According to this table, http://www.thedirtforum.com/castings.htm
    397348768-791.94/1.50
    & 2.02/1.6
    165-33076 CC Chambers
    X casting has 10 more intake
    cc volume.


    the only difference in the heads that I have is the x. 10 more intake cc's. Both have 76 cc chambers(75 cc on mortec). Will this matter for a couple of weeks running. Thanks
     
  4. TorkDSR

    TorkDSR 1/2 ton status

    Joined:
    Sep 1, 2001
    Posts:
    1,258
    Likes Received:
    0
    Location:
    bucks co pa
    the size of the valve wont affect the combustion chamber...

    but if the combustion chamber is a different size that would get weird
     
  5. R72K5

    R72K5 Banned

    Joined:
    Mar 5, 2001
    Posts:
    8,905
    Likes Received:
    0
    Location:
    central IL
    better get matching heads on that engine...

    make sure ones not been milled more than other too...

    larger valve head can affect volume displacement, so can seat and valve head margin wear- or lack thereof, IE distance valve head is protruding into chamber.. or not., it is measured in cc's
    a cc is not very much..

    common sbc head combustion chamber volumes are 58, 64, 72, theres some others too, oddball ones,



    good luck..,
     
    Last edited: Mar 22, 2005

Share This Page