Non pi heads on 04 2v??

Discussion in '96-04 - 2V Specific' started by Brandengonzo, May 31, 2020.

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  1. Brandengonzo

    Brandengonzo New Member

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    Don't ask me why because it hurts Everytime I have to think about what I'm doing to this poor guy... But I'm putting 97 gt (Romeo) heads on an 04 gt block. I've got it all assembled and am trying to time it out of the car. I should have, but did not time it when I removed it. Valves are hitting when I try to time the LH cam. First question, this will work right? Putting 97 heads on an 04 block? The combustion chamber on the 97 heads isn't smaller or something causing it to interfere? And second off, do you think I may just be 360 out on one of the cams causing the interference? Thanks a million, and I apologize if this reverse pi swap was covered somewhere but I could not find it lol
     
  2. white95

    white95 Apex Junky Admin

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    You know we’re going to ask... Won’t this lower the compression ratio?

    @96blak54 or @lwarrior1016 could answer this question
     
  3. Brandengonzo

    Brandengonzo New Member

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    Peobably, but is this achieved through a smaller combustion chamber on the head? Or a deeper dish on the piston??
     
  4. Brandengonzo

    Brandengonzo New Member

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    So the 04 pistons use a deeper dish piston, and the 97 heads use a larger cc combustion chamber right? I'm not 100% sure though so please correct me if I'm wrong. But if this is right, this combo should have moved the valves even further from interfering??
     
  5. Silver95bird

    Silver95bird Active Member

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    Check the timing. Something is wrong.

    Sent from my moto z3 using Tapatalk
     
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  6. lwarrior1016

    lwarrior1016 Moderator Staff SN95 Supporter

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    Your timing is definitely off. Start over on the timing, put the crank key at 9 o’clock and get the cams pretty close to where they are supposed to be, then put the crank timing dot at 6 o’clock and start timing.

    Now all that being said, you are going to lose compression. The pi pistons have a bigger dish and the npi heads have a bigger chamber, I don’t remember the numbers off hand but you’re going to lose a point or so. You’ll end up being in the 8ish area.

    The edge of the piston is where the valve is going to hit first. It’s not going to make a difference if it’s pi piston or npi piston.
     
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  7. 96blak54

    96blak54 Legend

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    He will be 2points lower compression....like 7:1.

    Be sure cams are on the correct sides.

    Take out the followers.

    Rotate crank key to 9oclock position

    Stretch the timing chains out. The links on the ends will mate to the timing marks on the sprockets. Take some paint and mark them links
    31932d1501889538-timing-procedure-97-03-two-valve-4-6l-5-4l-modular-engines-7924fg92.gif
    Pic is for a 5.4l. A 4.6l will be like the left side on both ends. Mark the end links.
     
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  8. BigBore96

    BigBore96 Active Member

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    Definitely do as suggested and start over.

    And like suggested do it with the followers out.

    Sent from my SM-N950U using Tapatalk
     
  9. Brandengonzo

    Brandengonzo New Member

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    Thank you guys for the quick response. Is it possible that the cam hear is 360 out? Of course I will visually see which valve is trying to open to determine this, but I'm just trying to get as much info as I can before I got the engine in front of me again. Thanks again everybody
     
  10. 96blak54

    96blak54 Legend

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    Yes its possible the cam is 360 out. Its possible you have 2 of the same cams when it should be a left and a right cam. Its possible cams are swapped. Its possible sprockets on wrong sides, on wrong cams, or 2 of the same sprockets....dang this list can just keep going! Ive never really thought about what could go wrong.
     
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  11. Addicted

    Addicted Active Member

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    Also remember to look at the engine as if you was sitting in the car. Passenger side is "RH" and Driver side is "LH". The crankshaft keyway can also be pointed to the 3'oclock position to get all pistons down in bore. Install all rockers on the base circle lobe of camshaft.
    Hypothetical speaking here, but if
    everything was correctly installed and if this was a PI head with aftermarket cams, I could say the factory gears could be advanced to far, and a great reason why you couldn't rotate the engine over, BUT since it's not and it's the total opposite of what I just said, you're timing is off, and go what was said above post.
     
    Last edited: Jun 1, 2020
  12. BigBore96

    BigBore96 Active Member

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    When it you get the time to dive into correcting this post up the cam part #s and we can make sure you have them installed correctly.

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