NPI shortblock PI head 4.6l re-build

Discussion in '96-04 - 2V Specific' started by 96blak54, Jan 11, 2018.

  1. 96blak54

    96blak54 Well-Known Member

    Messages:
    6,079
    Likes Received:
    6
    Joined:
    Feb 21, 2011
    Location:
    Ky
    Though id share this rebuild im currently on.

    Story goes, Buddy has a '99 GT that spit a spartplug out, destroying the head and piston. Did a stock new rebuild with a reman head and he got 500miles till the fuel pressure sensor crapped out. Replaced sensor, drove another 100miles and it crapped out again only this time it allowed fuel through. Ultimately into the intake manifold filling up the cylinders all the way into the oil pan. Wouldnt have been the case if we had discovered it sooner, but all the ignition on/offs was priming the engine full of fuel.

    Engine bearings DO NOT like gas! Tried fresh oil but no luck. Rod bearing spun!

    Here i am slappin parts together for a temporary engine so that we can build the one coming out and do it right.
     
  2. 96blak54

    96blak54 Well-Known Member

    Messages:
    6,079
    Likes Received:
    6
    Joined:
    Feb 21, 2011
    Location:
    Ky
    Pic shows .070" deep valve reliefs. Probably not needed, but hey...never know. Dang pesky pi heads and no ptv clearance. He has mentioned aftermarket cams, getting s tune, so its a "just in case" solution.

    How i did the valve reliefs?
    I took a junk head, clearanced out around all the intake valve seats and made a long stemmed valve looking tool that has a bigger diameter than a valve. Tool has a flat face surface with sticky velcro. I then take velcro backed sand paper, cut it same diameter, stuck it to tool face. Placed tool into head. Mounted head on block. Raised piston into place and used a hand power drill to rotate tool. Doesnt take long at all to achieve a .070" deep relief. Sand paper does 4 cylinders well. Unpeel paper and replace with new. Relief the other side. This keeps my cost low and provides a great relief. I wanted a tool that could make the cuts with out having a sharp tool radius. Possibility of starting a crack.[​IMG]
     
  3. 96blak54

    96blak54 Well-Known Member

    Messages:
    6,079
    Likes Received:
    6
    Joined:
    Feb 21, 2011
    Location:
    Ky
    After cleaning debri from reliefing pistons, it was time to clean the deck surface.

    I use rasor blades and scotch brite. First took a sharp blade over the surface scraping gasket material, rust, sludge...whatever. Next the scotch brite made good work cleaning the surface with a little bit more detail. 3rd i take another rasorblade and scratch the deck surface up real good. The scratches are microscopic and add a surface roughness more fitting for the headgaskets to be used. If stock gaskets were used, i would seek machining the proper surface roughness.[​IMG]
     
  4. lwarrior1016

    lwarrior1016 Well-Known Member SN95 Supporter

    Messages:
    4,951
    Likes Received:
    10
    Joined:
    Sep 22, 2014
    Location:
    South Mississippi
    Looking good, brother! Im excited to see what this combo ends up doing. I hope he gets a dyno tune for this thing.
     
  5. Silver95bird

    Silver95bird Well-Known Member

    Messages:
    158
    Likes Received:
    0
    Joined:
    Sep 5, 2016
    I'd love to see that tool setup! Looks good. If I were doing a pi build I'd consider reliefs a must. Keep us all updated, I'd love to see the Dyno!
     
  6. OLD H2S

    OLD H2S Well-Known Member SN95 Supporter

    Messages:
    727
    Likes Received:
    4
    Joined:
    Jul 4, 2015
    Location:
    Silver Spring Maryland
    I am not going to say a thing. I am George Castanza and you all should do the opposite of any thing I do.
     
  7. NEURON

    NEURON Well-Known Member

    Messages:
    86
    Likes Received:
    0
    Joined:
    Nov 10, 2016
    Location:
    SOCAL
    Any idea why two FPR's went out so quickly, especially the second one(new ?).
     
  8. 96blak54

    96blak54 Well-Known Member

    Messages:
    6,079
    Likes Received:
    6
    Joined:
    Feb 21, 2011
    Location:
    Ky
    The 1st one was a factory Ford unit, notorious for failure. The 2nd one was from O'Reillys and apparently the diaphragm popped allowing fuel to flow through the vacuum line, straight into the intake. No way of visually knowing!
     
  9. PinkieT

    PinkieT Well-Known Member

    Messages:
    912
    Likes Received:
    4
    Joined:
    Jun 22, 2015
    Location:
    Cleveland
    I love low buck shade tree mechanic solutions!