1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

compression ratio

Discussion in 'Engine Building' started by xaero, Jul 3, 2004.

  1. xaero

    xaero Member

    Messages:
    33
    Likes Received:
    0
    Joined:
    May 18, 2004
    What’s the highest compression ratio piston I can use with 93 octane gas, I am planing on building a lsvtec with a b18a1 block, with b16 head
     
  2. swanny

    swanny Senior Member

    Messages:
    3,779
    Likes Received:
    1
    Joined:
    Jul 13, 2003
    Location:
    buck teeth and government checks, PA
    An ls-vtec will be fine on 93, If you have proper tuning and fuel management you could run ~11.5:1 on 93
     
  3. JDMilan

    JDMilan Senior Member

    Messages:
    6,730
    Likes Received:
    0
    Joined:
    May 11, 2003
    Location:
    Boca Raton, FL
    depends on tuning, for pump 93 - me personally 12.0:1 would be my limit, but Calesta has run higher CR.

    Lots of variables affect it,
     
  4. phunky.buddha

    phunky.buddha Admin with a big stick Admin VIP

    Messages:
    28,465
    Likes Received:
    228
    Joined:
    Sep 30, 2002
    Location:
    Dallas / Fort Worth, TX
    Damn, post in the right forums people.

    :moved:

    Yes, I've run higher compressions on 93 octane, and there are people who run even higher than me. It's all in the tuning. I've run 12.6, 12.4 and currently 12.8:1 compression on pump gas, all on separate engine builds.
     
  5. B16

    B16 Super Moderator VIP

    Messages:
    11,539
    Likes Received:
    534
    Joined:
    Sep 30, 2002
    Location:
    yay area, CA
    yup, running 12.3:1 on cali 91 pump crap right now, runs great :)
     
  6. shaneb

    shaneb Member

    Messages:
    69
    Likes Received:
    0
    Joined:
    Jun 11, 2003

    Same here ....my cr is about 12.3.1 too. and i run 91 cali shit gas all day long...and have bin for about 6 mounths now




    MY setup:


    A b16 head w/portflow valve train,valve job,
    CnC drag ported
    head milled 20 under
    1 layer head gasket
    skunk2 stage 2 cams
    L Natural cam gears,
    stock gsr header
    Ls bottem end w/p30 pistons,
    Itr manifold,
    In a 91 Hatch dx w/azens tires 15' in
    2 1\2 strait piping all the way back w/ez muffler
    b16 s1 tranny
    vafc controller
     
  7. JDMilan

    JDMilan Senior Member

    Messages:
    6,730
    Likes Received:
    0
    Joined:
    May 11, 2003
    Location:
    Boca Raton, FL
    well....there you have it........and good luck
     
  8. StyleTEG

    StyleTEG Senior Member

    Messages:
    217
    Likes Received:
    0
    Joined:
    Oct 22, 2003
    Its all in the cams.

    More aggressive cams with longer duration are going to bleed off more compression due to the intake valve being open ABDC. You could run 12:1 CR, but if the cam is aggressive enough the dynamic compression could be in the 10:1 area.
     
  9. B16

    B16 Super Moderator VIP

    Messages:
    11,539
    Likes Received:
    534
    Joined:
    Sep 30, 2002
    Location:
    yay area, CA
    using just ctr cams :D
     
  10. phunky.buddha

    phunky.buddha Admin with a big stick Admin VIP

    Messages:
    28,465
    Likes Received:
    228
    Joined:
    Sep 30, 2002
    Location:
    Dallas / Fort Worth, TX

    :werd:

    That definitely makes a difference. Decreasing overlap with my stock B16 cams made me detonate- there was no way to run well on pump gas with 2 degrees less overlap.
     
  11. shaneb

    shaneb Member

    Messages:
    69
    Likes Received:
    0
    Joined:
    Jun 11, 2003
    And this is why they made Adjustable cam gears :D
     
  12. phunky.buddha

    phunky.buddha Admin with a big stick Admin VIP

    Messages:
    28,465
    Likes Received:
    228
    Joined:
    Sep 30, 2002
    Location:
    Dallas / Fort Worth, TX
    Yes exactly- so I could set my cams back to zero and not detonate. :p
     
Verification:
Draft saved Draft deleted

Share This Page