Neat write up on PI vs NPI vs SVO

Discussion in '96-04 - 2V Specific' started by caseypayne69, Sep 11, 2006.

  1. caseypayne69

    caseypayne69 Active Member

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  2. Lightning Struck

    Lightning Struck Legend

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    good info in there
     
  3. 97vertstang

    97vertstang Well-Known Member

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    nPI Heads:



    Combustion chamber volume: 51cc *

    Intake port volume: 146cc

    Intake valve diameter: 44.5mm

    Exhaust valve diameter: 34mm

    Intake flow @ .500 lift: 156cfm

    Exhaust flow @ .500 lift: 116cfm

    nPI Cams: .480 lift (duration at .500 = 204 intake, 208 exhaust)

    * Initial 4.6L engines utilized flat top pistons.



    PI Heads:



    Combustion chamber volume: 42cc **

    Intake port volume: 159cc

    Intake valve diameter: 44.5mm

    Exhaust valve diameter: 36mm

    Intake flow @ .500 lift: 156cfm

    Exhaust flow @ .500 lift: 133cfm

    PI Cams: .535 intake, .505 exhaust (duration: 192 intake, 184 exhaust)

    ** PI equipped engines utilized dish pistons to keep the compression ratio at 9.7-1.




    in there it says that npi cams have more duration and less lift. the pi cams have more lift but less duration. so modular engines like more lift than duration :dunno: or is that a typo??? i would think duration would give more power than lift??? at least on most other engines thats the way it works.
     
  4. blstang

    blstang New Member

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    that is some handy info thanx :thumb: