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Cylinder head/lifter question

Discussion in 'Gen 3 Prius Technical Discussion' started by donzoh1, Jan 28, 2019.

  1. donzoh1

    donzoh1 Active Member

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    When the cylinder head was off and camshafts were removed, two lifters fell out. I think they're back where they belong but not sure. At least I have a 50/50 shot at being right. I've measured some of these and there are several thousandths between them in length. Is there a way to tell whether they're right? I've heard there is zero clearance in the valves because these lifters are hydraulic.
     
    #1 donzoh1, Jan 28, 2019
  2. ChapmanF

    ChapmanF Senior Member

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    They are hydraulic. I think they're all the same part number (have you checked?). Could the difference in length you are measuring just be because some of them are squished more than others? They should all adjust right out to zero clearance once the engine oil pressure reaches them.

    There's a procedure in the repair manual for confirming they work right—requires a thin little tool to poke the check ball while trying to squish them in some oil.
     
    #2 ChapmanF, Jan 28, 2019
  3. cnc97

    cnc97 Senior Member

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    The lifters are the same. Any difference in the length is due to the oil inside. It’s preferred to put them back where they came out of, but it’s not a requirement.

    When I swapped the lifters from my Gen 4 head to the Gen 3, I had one of the heads facing opposite to the other one. The motor is closing in on 7k miles since and doesn’t care.
     
    #3 cnc97, Jan 28, 2019
  4. donzoh1

    donzoh1 Active Member

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    Thanks for the replies. I talked with the Felpro guy and he thought it was a potential big problem but my guess is it's not, due to the oil pressure inside. I have all the rockers and little buttons from the valve stems sorted into the correct sequence. I'm guessing it doesn't make any sense to try to use a feeler guage to measure camshaft/valve clearances. Is it a good idea to install camshafts before putting the head back on just to make sure the valves all seal when the camshaft rotates? I'm guessing this would be a waste of time, assuming the machine shop got the valves to seal. I kept the camshafts at home so they have not been put back in.
     
    #4 donzoh1, Jan 29, 2019
  5. cnc97

    cnc97 Senior Member

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    You must install the head first, before you can install the cams. It’s not possible to torque the head with the cams and cam bridge installed.
     
    #5 cnc97, Jan 29, 2019
  6. Dxta

    Dxta Senior Member

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    Head installed first.
    If you aren't comfortable with engine repairs/installation, please pau someone to do it.
     
    #6 Dxta, May 27, 2019
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