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Thread: Performance Heads

  1. #1
    Join Date
    Apr 2007
    Location
    New Orleans, LA
    Posts
    1,967

    Performance Heads

    here are pics of the heads off my 91 titanium auto supercoupe

    the engine was overheated big time, all 3 cylinders were blown on the driver side and cylinders 2 & 3 were blown on the driver side, so effectively it was a 1 cylinder lol but it was so warped that I had to shave 15 thousandths off just to get her flat again

    anyway, i pulled the heads with the intentions of just resurfacing them and slapping on mls gaskets....

    well after i was done sand blasting them and cleaning them up good, i pressure checked the valves and all 12 were leaking BADLY.

    So i started disassembling them, when i pulled the first valve i checked the guide and it was so loose that I had about 20 thousandths worth of play Needless to say all of the guides were worn extensively.

    so since it needed to be sleeved i figured i might as well go with larger valves. Well it didn't stop there, once the valves were done it just didn't make sense not to port the heads

    so heres the final outcome. They haven't been flowed yet but i know it flows alot better than before, hoping to use a friends flow bench to find out the truth.





















    anyway my main point was that if this combo does prove to give some substantial gains there just may be a few more sets done

    but first i want to see what kind of power these things make, i may throw them on my bone stock 94 5spd and throw it on the dyno, its completely unmolested so it would be a great test specimen. However unfortunately I do not have any prior dyno pulls from the car so it wouldn't be quite exact but enough to get an idea.

    if anyones interested shoot me a PM

  2. #2
    Join Date
    Oct 2008
    Location
    St Charles(near St Louis)
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    431
    Pm sent......

  3. #3
    Join Date
    Nov 2005
    Location
    Oregon 97220
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    1,018

    Thumbs up

    Those exhaust ports look fantastic! (all parts of those heads do)
    That's what I shot for with my porting. I see the bump and a slight radius like in my own.
    Nice.

  4. #4
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    Apr 2007
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    what you see there is whats known as a 5 angle valve job

  5. #5
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    Jan 2009
    Location
    south florida
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    399
    price please

  6. #6
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    Apr 2007
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    no idea as of yet since these heads still haven't been flowed, we've been slammed at the machine shop so as the saying goes... work before play

  7. #7
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    Apr 2007
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    New Orleans, LA
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    dropped the heads off to get flowed... awaiting the results, I'll post back with the numbers

  8. #8
    Join Date
    Jan 2009
    Location
    south florida
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    If you decide to do more heads and keep the price competative I'll take a set. how large are the valves you plan to put in those heads?

  9. #9
    Join Date
    Apr 2002
    Location
    Clear Lake, Houston
    Posts
    1,198
    Awaiting the flow numbers.

  10. #10
    Join Date
    Apr 2002
    Location
    St. Charles, MO
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    21,099
    What size valves are you using ?

    David
    1991 SC AOD 4.2..2.3 Whipple..........10.910 @ 125.61
    2016 SRT Challenger Hellcat.............10.597 @ 135.78

    My Garage

  11. #11
    Join Date
    Nov 2005
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    Oregon 97220
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    1,018
    Quote Originally Posted by decipha View Post
    what you see there is whats known as a 5 angle valve job
    5 angle is overkill IMO...

  12. #12
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    Jun 2009
    Location
    Rochester NY
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    31
    any idea of a price yet, flow numbers and what valve sizes are

  13. #13
    Join Date
    Apr 2007
    Location
    New Orleans, LA
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    these are the gm valves which are recommended around here to be the ideal large valve replacement

    the heads have been flowed and showed nice improvements at .1-.4 lift but maxed out at .5 and didn't flow any more at .6

    this is on par because the intake side was barely kissed, we wanted to flow it first to have something to compare to, the exhaust side was cleaned up so we expect the exhaust to show big improvements, won't know until the exhaust is flowed, hoping to have those results within the next week.


    im currently talking with dave dalke to get his insight. I'll post back with my findings.

    overall i'm very excited with the results, im hoping we can get some more done to it and send them off to dave dalke for his approval.

    shall see soon but i want everyone to remember, this is all being done after hours when we get free time. Once there done and the gains are known these will become the template and we'll be doing many sets of them.

    stay tuned

  14. #14
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    Jan 2009
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    south florida
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    hells yeah.

  15. #15
    Join Date
    Apr 2007
    Location
    New Orleans, LA
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    gm 305 intake valve
    intake - 1.84
    exhaust 1.56

    actual flow numbers from bench non ported just big valves
    .100 - 69.3 +26%
    .200 - 122 +24%
    .300 - 161 +23%
    .400 - 182 +13%
    .500 - 189 +9%
    .600 - 189 +4%

    stock
    .100 - 55
    .200 - 98
    .300 - 130
    .400 - 160
    .500 - 172
    .600 - 181

    typical big valve
    .100 - 58
    .200 - 108
    .300 - 156
    .400 - 192
    .500 - 208
    .600 - 204

    ported big valve
    .100 - 68
    .200 - 130
    .300 - 177
    .400 - 208
    .500 - 211
    .600 - 215

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