Flat top pistons suck.

Discussion in 'SN95 4.6 Talk' started by SonicStangGT, Aug 30, 2008.

  1. SonicStangGT New Member

    Member Since:
    Mar 18, 2008
    Message Count:
    122
    Likes Received:
    0
    Trophy Points:
    0
    Well about two weeks ago I was driving my car and every since I put the motor back in something had not been right with the tranny. Well missed fourth gear some how and bent a valve on the driver side. Did a compression check and on that cylinder I have 25 psi and I think its supposed to be 185-195. There was little to no PTV clearence with the stock cobra pistons. I dont see how anybody has made those pistons work in a 2 valve. I got stock cams, and had the pistons flycut for the intake valves. Also to much compression, if I dont put any 110 in with the 93 it sparknocks alot. I going to have to take to motor out and replace the pistons and I guess do some other things. This motor build went so wrong that I dont want to start another, but I have got alot my info for the build. Looking at stage 2 cams with either forged pistons and rods or just rebuild with stock stuff. What ever the budget allows. It sucks because I just had the motor out for about 4 months and just put 1100 miles on the fresh motor, know its coming back out. Like my DAD says, IF YOU PLAY, YOU PAY.
  2. 98COBRA281 Active Member

    Member Since:
    Nov 25, 2007
    Message Count:
    1,367
    Likes Received:
    8
    Trophy Points:
    38
    i hope you dont mean mark 8 pistons:(
  3. SonicStangGT New Member

    Member Since:
    Mar 18, 2008
    Message Count:
    122
    Likes Received:
    0
    Trophy Points:
    0
    They were out of a 96 cobra.
  4. CobraRed_96_GT Active Member

    Member Since:
    May 20, 2006
    Message Count:
    1,642
    Likes Received:
    0
    Trophy Points:
    36
    There's new a pair of VT stage II cams on Corral.net that it looks like the guy will let got for $375+ shipping. And i believe another new pair for $400. That's crazy good.
  5. darkside03gt Member

    Member Since:
    Feb 20, 2007
    Message Count:
    865
    Likes Received:
    3
    Trophy Points:
    18
    if your gona pull it again just get forged pistons and rods. you can get both for around $700. lower the compression into the mid 9s or lower and get some boost. your stock cast iron crank will take you to around 6-700 hp depending on who you talk too. to hell with n/a. BOOST.
  6. SonicStangGT New Member

    Member Since:
    Mar 18, 2008
    Message Count:
    122
    Likes Received:
    0
    Trophy Points:
    0
    Thanks for the info.
  7. SonicStangGT New Member

    Member Since:
    Mar 18, 2008
    Message Count:
    122
    Likes Received:
    0
    Trophy Points:
    0
    YEAH I WISH, cant afford boost yet. But am going with a mid 9 or upper 8 for the comprssion so later I can add boost.
  8. 04YELLOWGT New Member

    Member Since:
    Jun 30, 2005
    Message Count:
    1,197
    Likes Received:
    0
    Trophy Points:
    0
    Isn't that all they cost if when you bought them from VT? I only paid 375-400 when I bought mine from VT.
  9. CobraRed_96_GT Active Member

    Member Since:
    May 20, 2006
    Message Count:
    1,642
    Likes Received:
    0
    Trophy Points:
    36
    around $530-545 from CMS, at VT it was around the same before they went under
  10. 04YELLOWGT New Member

    Member Since:
    Jun 30, 2005
    Message Count:
    1,197
    Likes Received:
    0
    Trophy Points:
    0
    Yikes wonder why/how I got mine so cheap from VT.
  11. BurningRubber Active Member

    Member Since:
    Dec 6, 2004
    Message Count:
    2,691
    Likes Received:
    4
    Trophy Points:
    48
    Damn man, that is horrible!!!

    I hope everything goes right this go around.



    Did you make it down to Mustang Week this year?
  12. SonicStangGT New Member

    Member Since:
    Mar 18, 2008
    Message Count:
    122
    Likes Received:
    0
    Trophy Points:
    0
    Man I made it about 5 mins away and my car started to act up, so I had to turn around. My whole beach trip was a disaster. But hopefully like you said, maybe this time will be better. I just want a set of cams and my spray back so I can hit the track again. Looking for that low to mid 7's in the 1/8.
  13. BurningRubber Active Member

    Member Since:
    Dec 6, 2004
    Message Count:
    2,691
    Likes Received:
    4
    Trophy Points:
    48
    That sucks man, sorry to hear.

    Good luck with it, don't give up... lol.

Share This Page