Results 1 to 10 of 10

Thread: PISTONS ??

  1. #1
    Certified Gearhead
    Join Date
    Dec 2003
    Posts
    463
    Rep Power
    22

    Default PISTONS ??

    How can i find out the compression of my pistons that I am going to install in my car???? I was told they were high compression but is there anyway to tell exactly????? Thanks Ricky

  2. #2
    Afghan Goober! TheChosenOne's Avatar
    Join Date
    Sep 2006
    Location
    my momma's house
    Age
    37
    Posts
    2,206
    Rep Power
    23

    Default

    First, the compression of a piston is not necessarily the the pistons actual compression, but rather the compression ratio that will be yeilded by the cylinder itself when the piston is in your motor. The same piston will yeild different compression ratios depending on the head/block combo.
    First, you need to figure out what kind of piston you have: PR3, PR4, P72...ect. As far as oem pistons go, Ls yeild the lowest compression ratio, followed by GSR pistons, then ITR pistons, then b16 pistons, and the higest are ctr pistons.

    Here is a rough estimate of the compression ratios that your specific setup will yeild with the different oem pistons.

    (information from b20vtec.com)

    B16A block, B16 head and:
    GS-R pistons 8.7
    USDM ITR pistons 9.5
    92-93 GS-R pistons 9.56
    JDM ITR pistons 9.9
    B16A pistons 10.2
    CTR pistons 10.8

    B16A block, GS-R head and:
    GS-R pistons 9.0
    USDM ITR pistons 9.9
    92-93 GS-R pistons 9.94
    JDM ITR pistons 10.3
    B16A pistons 10.6
    CTR pistons 11.3

    B18C block, B16/ITR head and:
    GS-R pistons 9.65
    USDM ITR pistons 10.6
    92-93 GS-R pistons 10.64
    JDM ITR pistons 11.0
    B16A pistons 11.36
    CTR pistons 12.0

    B18C block, GS-R head and:
    GS-R pistons 10.0
    USDM ITR pistons 11.0
    92-93 GS-R pistons 11.1
    JDM ITR pistons 11.5
    B16A pistons 11.9
    CTR pistons 12.6

    B18B (LS) block, B16/ITR head and:
    GS-R pistons 9.8
    USDM ITR pistons 10.8
    92-93 GS-R pistons 10.84
    JDM ITR pistons 11.2
    B16A pistons 11.6
    CTR pistons 12.3

    B18B (LS) block, GS-R head and:
    GS-R pistons 10.2
    USDM ITR pistons 11.2
    92-93 GS-R pistons 11.3
    JDM ITR pistons 11.7
    B16A pistons 12.1
    CTR pistons 12.85
    Trend settin'

  3. #3
    Afghan Goober! TheChosenOne's Avatar
    Join Date
    Sep 2006
    Location
    my momma's house
    Age
    37
    Posts
    2,206
    Rep Power
    23

    Default

    P.S.

    Keep in mind that the common misconception that the higher the compression, the more the horsepower. While this might be true, 93 octane pump gas has a threshold at about 12.5:1. And really, any motor in the 12's has some serious tuning done to it.
    As far as street applications go, keep it between 9:1 and 11.5:1. Anywhere above that will cause your engine to detonate and/or lean out which will be bye-bye to your setup.

    ...................rep's please
    Trend settin'

  4. #4
    Certified Gearhead
    Join Date
    Dec 2003
    Posts
    463
    Rep Power
    22

    Default

    I guess i should have said what i had to make it a little easier. SORRY. I have a d16z6 block with JE SRP cutom made pistons(as i was told). The only thing the pistons have on them is SRP and the number 10. I am buying a ZC head that has been built with cam valve etc and port and polish plus he has the ecu chromed for a high comp motor. I wanna make sure i do this right though.

  5. #5
    Afghan Goober! TheChosenOne's Avatar
    Join Date
    Sep 2006
    Location
    my momma's house
    Age
    37
    Posts
    2,206
    Rep Power
    23

    Default

    Damn you just knocked my black ass back down to earth. This is what I get for getting cocky. Lol.

    Na, but foreal. Either contact the dude who you got the pistons from, or call the company. Are you going boost, spray, or N/A?
    Trend settin'

  6. #6
    Certified Gearhead
    Join Date
    Dec 2003
    Posts
    463
    Rep Power
    22

    Default

    Goin NA. Tryed callin JE(THEY SUCK) The guy said whats the part number and without that he couldnt help. The guy I got the pistons block and rods from said his head was shaved and he was running 13;1 which mine is not shaved. The one im gettin the head from hadthe ecu programed for 12;1. By the way I really appreciate the advice.

  7. #7
    Afghan Goober! TheChosenOne's Avatar
    Join Date
    Sep 2006
    Location
    my momma's house
    Age
    37
    Posts
    2,206
    Rep Power
    23

    Default

    Quote Originally Posted by rickylsi
    Goin NA. Tryed callin JE(THEY SUCK) The guy said whats the part number and without that he couldnt help. The guy I got the pistons block and rods from said his head was shaved and he was running 13;1 which mine is not shaved. The one im gettin the head from hadthe ecu programed for 12;1. By the way I really appreciate the advice.
    No problem man. I know, when your building a motor, you always want to try and do everything perfect to limit the number of things that could go wrong. Well, with the little information the guy gave you, your probably going to be in the high 12's. Did he have the d16 block with the zc head, too? Honestly, the safest, and only way your gunna be able to tell is to find out the exact number of cc's in yor combustion chamber and work the math yourself. There is a web site that has the equation, but honestly... its tough shit.
    Trend settin'

  8. #8
    Certified Gearhead
    Join Date
    Dec 2003
    Posts
    463
    Rep Power
    22

    Default

    Cool thanks again.

  9. #9
    BOOB koukis14's Avatar
    Join Date
    Aug 2006
    Location
    Pennsyltucky
    Age
    42
    Posts
    4,255
    Rep Power
    25

    Default

    Quote Originally Posted by TheChosenOne
    P.S.

    Keep in mind that the common misconception that the higher the compression, the more the horsepower. While this might be true, 93 octane pump gas has a threshold at about 12.5:1. And really, any motor in the 12's has some serious tuning done to it.
    As far as street applications go, keep it between 9:1 and 11.5:1. Anywhere above that will cause your engine to detonate and/or lean out which will be bye-bye to your setup.

    ...................rep's please
    isn't the compression ratio in an S2000 12.5:1?

  10. #10
    Afghan Goober! TheChosenOne's Avatar
    Join Date
    Sep 2006
    Location
    my momma's house
    Age
    37
    Posts
    2,206
    Rep Power
    23

    Default

    Quote Originally Posted by koukis14
    isn't the compression ratio in an S2000 12.5:1?
    hahaha... honestly, I couldn't tell you. But consider this........If it does come off the assembly line at 12.5, then I assure you that HONDA tuned the SHIT out of that motor. But I would like to see somemore info on this racing spec S2000 you speak of.
    Trend settin'

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
About us
ImportAtlanta is a community of gearheads and car enthusiasts. It does not matter what kind of car or bike you drive, IA is an open community for any gearhead. Whether you're looking for advice on a performance build or posting your wheels for sale, you're welcome here!
Announcement
Welcome back to ImportAtlanta. We are currently undergoing many changes, so please report any issues you encounter with the site using the 'Contact Us' button below. Thank you!