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who's got the highest compression?

Discussion in 'The Distillery' started by IUP99snake, Apr 18, 2011.

  1. rockthemullet

    rockthemullet Member Established Member

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    x2
     
  2. blowngt

    blowngt Active Member Established Member

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    I'm guessing that the reliefs help lower the compression just a bit. My pistons are true flat tops......no reliefs.

    If you're running E85 I wouldn't worry to much about compression. If/when I ever rebuild, I'm going to see about going just a bit higher......like 11.0 or 11.5:1.

    The throttle response and power comparision to the 17cc pistons I had before is just night and day........
     
  3. 01bluesnake

    01bluesnake Authorized Vendor Authorized Vendor Established Member

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    You are making me worry about my comp now lol. I also ordered my pistons through MMR, but they didnt mention any change from the valve notching even though i figure it will have an effect on comp. They are suppose to be a -4cc ".030 piston on a 3.75" stroke, so not sure if they calculate the -4cc after the notching or before, but would assume after. Going to call them tomorrow to double check.
     
  4. 04gtstang

    04gtstang Member Established Member

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    Holy crap! That would be approaching the limit of C16 no doubt...E85 is some amazing fuel! I havnt heard of anyone hitting the point where they get knock...makes me wonder how far it can go.
    Ill be going high compression for sure now when I rebuild the GT engine. Maybe 12-1...20PSI. Good combo.
     
  5. DaveHutch

    DaveHutch Bullets and Cars n stuff Established Member

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    I just bought a teskid, 10.2:1 compression. i am putting a 2.2 kb on it, and running a return style with E85! hoping it will turn out very steady, responsive and have some good numbers on only 19 psi.
     
  6. Hmbre97

    Hmbre97 Eaton powered Established Member

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    Geez, I wimped out when building my motor. Wound up only going 9.3:1 with fears of E85 not being avail someday or my local station shutting down. Didn't want to be forced into running race fuel.

    Now all these posts make me wish I grew a pair and put some flat tops in it. Oh well :/
     
  7. oldmodman

    oldmodman Well-Known Member Established Member

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    I really envy all the lucky people that have E-85 locally available.
    With only 91 octane available here in Los Angeles I will have to build an engine with "maybe 9 to 1" And even then i will be limited to 17psi at low advance or it will detonate to death.

    But just as an example of how much static and boost you can run. I worked on a streamliner at Bonneville that was 14.2 to 1 static and boost that went from 15 psi in first, up to 65 psi in fifth, burning pure methanol. And after a run the outside of the intake had ice on it. We did not need to run an intercooler at all.
    It was a motorcycle streamliner powered by a pair of 998cc Kawasaki 4 cylinder engines. It had over a thousand horsepower while going thought the traps at the five mile. It went 371mph.
     
  8. the anti-rice

    the anti-rice Member Established Member

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    Damn...seems like Ive got the lowest at 8.5:1 Built the motor a year ago and never even thought of E85. Car isnt back together yet but we'll see how it runs.

    B-headed 4V .20 over
    stock cams
    built bottom end
    Precision T76 with a .96 a/r.
     
  9. corysmach1

    corysmach1 Active Member Established Member

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    Im looking into doing a high comp Na nitrous build. 13:5:1 comp on E85 of course.....we will see.
     
  10. Mach1soldier

    Mach1soldier Member Established Member

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    Just curious what your build plan would be and how much you intend to spray? I know you haven't started but you are the first person I have come across to mention anything even similiar to what I am in the middle of.

    Here is my combo that I am piecing parts together for.

    4.6 big bore block
    Custom diamond 10CC dome pistons
    Forged connecting rods (need to get)
    GT crank
    Stock heads or possibly get livernois to port them but thats a longshot.
    PSRI by Todd or NASVT
    Unknown cams... Either cobra intake cams or customs.
    125 shot on NX wet kit, single nozzle.

    Its an auto car so I'm trying to maximize power and torque from 3000-6500. Hopefully shift at 6800 or so. I'm hoping the extra compression (12.9-1) and extra cubes help increase the mid range torque for better 60 foot times.
     
  11. Turbo900rr

    Turbo900rr Member Established Member

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    2012 gt 11 to 1 compression, 12 psi through a d1sc procharger stage 2 intercooler on e85. no dyno numbers yet but hopefully by the end of next week.
     
  12. mustangcobratim

    mustangcobratim wannatry? Established Member

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    now thats bad ass!
     

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