Does this valvetrain geometry look ok?

Discussion in 'Engine Topic' started by fstarocka, Jan 22, 2021.

  1. fstarocka

    fstarocka Member

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    Hi all - busy finalizing the 383 in the garage -


    Cam is comp XR288, 1.6 roller rockers, ARP screw in studs, +0.100 long valves, procomp alu heads.


    I put the geometry tool on at zero lift and it looked fine..


    Popped in the comp 5/16 pushrod (7.250 length - 5/16) -


    The crane roller tip rocker just looks a little angled - the wear pattern is slightly over the center but not a lot - I put the bare head on as I wanted to check PVC as well, so the 0.014 shim should only slightly raise the head which would probably center the pattern a little more -


    Im probably ok with the pattern but the rocker seems angled - this ok?



    At zero lash:


    [​IMG]



    Wear pattern almost perfectly centered:

    [​IMG]






    Does this angle look ok?


    [​IMG]
     
  2. ChevyReb

    ChevyReb Veteran Member Lifetime Gold Member

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    Is the cam a small base circle? And you have no head gasket on it yet? When I did mine I think I had the heads installed and torqued to spec. I do recall using the low tension spring like you have. I don't think I've seen the blue plastic false rocker.
     
  3. fstarocka

    fstarocka Member

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    not small base and i did not have the shim gasket on - it would only make a tiny difference but i will re check of course- kinda shopping for rockers.. another 200 off the wallet!
     
  4. 1980RS

    1980RS Veteran Member

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    Looks pretty good to me.
     
  5. sandlapper

    sandlapper Veteran Member

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    with different rockers, suggest you repeat your measurements.

    Real valve springs Usually pull valve a little tighter to seat while raising tip a smidge. But it sounds like you're getting very close regardless.
    [​IMG]
     
  6. 1320feet

    1320feet Veteran Member

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    Looks good to me.
     
  7. Rosster

    Rosster Veteran Member Gold Member

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    Any reason why your not looking at alignment at 1/2 of lift? That’s where lifter should be in the exact center on the stem and rocker body parallel with retainer.
     
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  8. fstarocka

    fstarocka Member

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    Im redoing that check - i used the geometry checker tool and mine was perfect, and i roleed it over and the wear pattern looks ok but ill confirm once new rockers arrive.

    Comp pushrod tool arrived so bound (red loctite!) i have to turn it in the bench vice!
     
  9. fstarocka

    fstarocka Member

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    trying to locate guide plates with holes for center bolt valve covers.. ?
     
  10. 1320feet

    1320feet Veteran Member

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    Also check the rockers slot to stud clearance at both ends. Usually one uses longer valves to allow for taller springs. Usually with taller springs one uses larger retainers. That's a small retainer in your photo. If you are using larger retainers, also check clearance between rocker and retainer. If you don't need the longer valves, I wouldn't use them. Your rocker arm is up high on the stud. A shorter valve will place the rocker lower on the stud where it's stiffer.
     

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