Setting cold valve lash on a solid cam

Discussion in 'Engine Topic' started by Joe Prather, Nov 30, 2009.

  1. Joe Prather

    Joe Prather Veteran Member

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    Jan 21, 2002
    Cynthiana, Kentucky
    Hi everyone, I just installed my new solid flat tappet Elgin cam today and now I'm ready to set the lash. The problem is, the only info I can find about the lash is to set the valves at .026 hot. I can't find anything for the cold setting. Should I set them at .026 anyway?
    I made all of the precautions that are neccesary for a good break in. I just wanted to make sure I have my lash in the ballpark when I start it for the first time.

    Thanks for your time,

    Joe
     
  2. High Country Z

    High Country Z Veteran Member

    Someone else asked this same question last week, when setting lash cold the GM service manual recommended an extra .002 lash. After reaching operating temp. recheck and set at recommended hot settings.
     
  3. Damon

    Damon Veteran Member

    12,808
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    Nov 16, 2000
    Philly area
    I always set it tighter on a cold engine. .002" tighter than spec with cast iron heads, .004" tighter than spec with aluminum heads.
     
  4. scrapmetal

    scrapmetal Veteran Member Lifetime Gold Member

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    Jul 5, 2007
    Cleburne,Texas
    I agree with Damon.After it gets warmed up check it to be sho!
     
  5. Rick WI

    Rick WI Veteran Member

    10,408
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    Jul 9, 2001
    Madison, WI
    You set lash TIGHTER on cold lash.....end of story that is how it's done. Reduction in lash on cold adjustment is dependent on cylinder head and block material, all steel, less compensation, all aluminum more compensation...to the tight side.

    Set at .022 - .024.
     
  6. Joe Prather

    Joe Prather Veteran Member

    670
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    Jan 21, 2002
    Cynthiana, Kentucky
    Thanks for the replies everyone. I'm going to set them at .024 later today.

    Thanks again!

    Joe
     
  7. "When installing a new cam, the engine will be cold but the lash specifications are for a hot engine. What are you to do? There is a correction factor that can be used to get close. We mentioned that the alloy of the engine parts can be affected by thermal expansion in different ways, therefore the amount of correction factor to the lash setting depends on whether the cylinder heads and block are made out of cast iron or aluminum.

    You can take the "hot" setting given to you in the catalog or cam specification card and alter it by the following amount to get a "cold" lash setting.

    With iron block and iron heads, add .002"
    With iron block and aluminum heads, subtract .006".
    With both aluminum block and heads, subtract .012".
    Remember this correction adjustment is approximate and is only meant to get you close for the initial start up of the engine. After the engine is warmed up to its proper operating temperature range, you must go back and reset all the valves to the proper "hot" valve lash settings."

    This is from Crane Cams Website, so it all depends on if your heads are iron or aluminum? Enjoy :bowtie:
     
  8. Battmann

    Battmann Veteran Member

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    Sep 12, 2007
    North Chili, NY
    link to above reference website (i use it all the time):
    http://cranecams.com/?show=techarticle&id=2
     
  9. Joe Prather

    Joe Prather Veteran Member

    670
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    Jan 21, 2002
    Cynthiana, Kentucky
    Thanks REARSPROCKET and Battmann, after reading the link it appears I should set my lash ay .028. My hot lash is .026, so I need to add .002 to that.

    Thanks for the help guys!

    Joe
     
  10. GetMore

    GetMore Veteran Member Lifetime Gold Member

    2,863
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    Nov 8, 2004
    Patterson, NY
    Do us a favor and once you've got the engine up and running check the lash and tell us how it compares when hot. It would be interesting to see if the info Crane gives (posted above) matches what happens on your engine.
     

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