Results 1 to 13 of 13
Like Tree1Likes
  • 1 Post By crew chief

Thread: compression ratio on 2002 ls1

  1. #1
    Ride
    vy v6

    Join Date
    May 2010
    Posts
    50

    Default compression ratio on 2002 ls1

    just want to no what the sandard compression ratio on my vu ss is standard heads and gaskets.
    The recomended ratio for the cam i want is 9.5-1. whats the best way to change the compression ratio. shave heads or new head gaskets

  2. #2
    Ride
    2009 VE SS and 2010 CX captiva

    Join Date
    Jan 2008
    Location
    mount gambier SA
    Posts
    43

  3. #3
    Ride
    vy v6

    Join Date
    May 2010
    Posts
    50

  4. #4
    Munz's Avatar
    Munz is offline Right Foot Action
    Ride
    VZ Calais LS1 / VL RB30e daily

    Join Date
    Jan 2011
    Location
    Brisbane NTH
    Posts
    947

  5. #5
    Ride
    vy v6

    Join Date
    May 2010
    Posts
    50

    Default cam

    HYDRAULIC ROLLER: Street/strip, needs 9.5:1 CR , 2800+ stall, intake, gears, & headers, very rough idle.
    COMP CAM
    BIG MUTHA THUMPR THUMPER
    IN 235
    EX 249
    IN .573
    EX .558
    109°

  6. #6
    Ride
    vy ss commodore 5.7ltr

    Join Date
    Jul 2006
    Posts
    1,038

    Default

    vu should be the ls1 10.1:1 comp, i think the only way you could do it is to put dished pistons in, as shaving the heads will increase your compression ratio as your making the combustion chamber smaller in the way of the chamber/bowl on the heads becomes smaller increasing the comp.

    could put in a thicker head gasket, i know not ideal but would need to go to a .060-0.065" thick head gasket with standard head chambers, could still how ever do bigger valves and increased port flow without shaving the heads. could increase the bowl chamber size as well i think by machining/increasing the bowl diameter on the heads, which would help drop the compression a little, maybe enough with a thicker headgasket(don't quote me on that i could be wrong on that part).

  7. #7
    Ride
    A slow1

    Join Date
    Nov 2005
    Posts
    32

    Default

    who the fark told u to lower your compression? my ls1 has 9.5c/r and gets 15 pounds of boost shoved down its throat...

    up the compression if anything, lowering with make less power

  8. #8
    Ride
    vy ss commodore 5.7ltr

    Join Date
    Jul 2006
    Posts
    1,038

    Default

    iv seen the comp cam specs for this cam and it says exactly what phat vy posted, requires 9.5:1 comp, the book iv got says 10.1:1 comp as well for the ls1.

  9. #9
    Ride
    vy v6

    Join Date
    May 2010
    Posts
    50

    Default hmmm

    year i was going to shave my heads to raise the compression. i dont want to drop CR but that's what is recommended. I don't see what you gain by droping the CR, the smaller version of this cam said the recommended CR is 9-1.
    can anyone tell me what i would gain by lowering my CR.

  10. #10
    Ride
    WK Stato

    Join Date
    Oct 2008
    Posts
    99

    Default

    Mate I think you will find that the manufacturers specs of 9.5cr is the minimum comp you would need to run this cam not what you have to have....the more comp the better, stick some e85 down its throat and go nuts on the comp ...do it

  11. #11
    Ride
    A slow1

    Join Date
    Nov 2005
    Posts
    32

  12. #12
    Ride
    vy ss commodore 5.7ltr

    Join Date
    Jul 2006
    Posts
    1,038

    Default

    this should open up to it: 54-602-11 - Thumpr
    seen some good results from higher comp and E85 if you can find it, went in a cam and head package ls1 with higher comp and E85, absolute weapon, made an x amount extra rwkw, its won some dyno comps for n/a ls1, made 300+rwkw cam and head package on E85 and daily driven.

  13. #13
    Ride
    vy v6

    Join Date
    May 2010
    Posts
    50

    Default Mad

    Quote Originally Posted by crew chief View Post
    Mate I think you will find that the manufacturers specs of 9.5cr is the minimum comp you would need to run this cam not what you have to have....the more comp the better, stick some e85 down its throat and go nuts on the comp ...do it
    year thats what i like to here migh give my tuner a call and see what he thinks.
    Has anyone used this cam, does anyone have some time or dyno results cheers

Similar Threads

  1. Compression Ratio
    By GunnaBeSumthingVP in forum VR - VS Holden Commodore (1993 - 1997)
    Replies: 6
    Last Post: 14-01-2011, 05:02 PM
  2. Compression ratio
    By maldotcom2 in forum VR - VS Holden Commodore (1993 - 1997)
    Replies: 12
    Last Post: 12-09-2009, 09:30 PM
  3. Compression Ratio?
    By shanna72au in forum VR - VS Holden Commodore (1993 - 1997)
    Replies: 3
    Last Post: 25-06-2009, 09:06 PM
  4. Compression ratio
    By geardys in forum V8 Development and Modification
    Replies: 16
    Last Post: 04-11-2007, 07:11 PM
  5. compression ratio
    By vkhawkey in forum VB - VK Holden Commodore (1978 - 1985)
    Replies: 3
    Last Post: 20-04-2007, 11:10 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71