Results 1 to 9 of 9

Thread: valve lash setting

  1. #1
    Junior Member JOURNEYMAN
    Join Date
    Nov 2006
    Location
    san antonio,texas
    Posts
    28

    valve lash setting

    I just bought a new set of AFR heads, and as i was reading there directions, It said to run the valve lash .006 tighter than normal. I am running aluminum heads on a iron block.
    i have never heard of this, is this true??????

  2. #2
    Senior Member DYNO OPERATOR
    Join Date
    Apr 2008
    Posts
    504
    Cold valve lash with aluminum heads will measure about .006 greater when they heat up so when the engine is fresh you set the lash at .006 tighter cold to get started. Always lash the engine hot for an accurate final setting. The head will expand at different rates along the head due to thermal mass and unequal heating which is the condition that the engine runs in. Always do the lash and check it at the same temp every time. The hotter temp that you set them at the tighter they will be when cold.
    Bruce

  3. #3
    Senior Member RACING JUNKIE
    Join Date
    Jun 2003
    Location
    Hobbs, NM
    Posts
    842
    Quote Originally Posted by TopspeedLowet
    Cold valve lash with aluminum heads will measure about .006 greater when they heat up so when the engine is fresh you set the lash at .006 tighter cold to get started. Always lash the engine hot for an accurate final setting. The head will expand at different rates along the head due to thermal mass and unequal heating which is the condition that the engine runs in. Always do the lash and check it at the same temp every time. The hotter temp that you set them at the tighter they will be when cold.
    Bruce
    X2, thats also why you need to let your engine heat up before you start ripping the throttle....

  4. #4
    Senior Member RACING JUNKIE
    Join Date
    Sep 2007
    Posts
    4,143
    Just set them cold.Once it warms up check them and see how much they changed and then do the math....I set mine at .016 cold and when it warms up they are .022-.023 . Iron block aluminum heads.

  5. #5
    Senior Member RACING JUNKIE
    Join Date
    Jul 2007
    Location
    Independence, Missouri
    Posts
    1,188
    Quote Originally Posted by Tod74
    Just set them cold.Once it warms up check them and see how much they changed and then do the math....I set mine at .016 cold and when it warms up they are .022-.023 . Iron block aluminum heads.
    X2
    No matter where you go, there you are.
    **IN GOD WE TRUST**

  6. #6
    Senior Member RACING JUNKIE
    Join Date
    May 2006
    Posts
    2,044
    X3
    ***IN GOD WE TRUST***

  7. #7
    Senior Member SENIOR BUILDER
    Join Date
    Nov 2007
    Location
    indiana
    Posts
    123
    ok then my cam said to adjust mine at .025 in and ex is that way to much if it expands that much?????????solid roller steel on steel
    if something goes wrong there is always the cooler!!!

  8. #8
    Junior Member JOURNEYMAN
    Join Date
    Nov 2006
    Location
    san antonio,texas
    Posts
    28
    i always have just brought it to temperture and set the valves,never had any problems. i did not no about the .006 tighter for alum heads.
    30 years of doing this and still learning. no wonder i am still slow !!!!
    Thanks for the imfo-----

  9. #9
    Senior Member RACING JUNKIE
    Join Date
    Jun 2003
    Location
    Hobbs, NM
    Posts
    842
    Quote Originally Posted by nova77
    i always have just brought it to temperture and set the valves,never had any problems. i did not no about the .006 tighter for alum heads.
    30 years of doing this and still learning. no wonder i am still slow !!!!
    Thanks for the imfo-----
    Your instructions were for setting them cold. Aluminum heads grow more than steel heads. They're just giving you a round about figure to set your valves cold. Like it was said earlier set your lash at .024 to .026 hot or whatever your cam recommends. Then check after your engine has cooled off, that will we your variance, and it will probably be close to .006.


Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Email us - Support@RacingJunk.com
Call us - 866.326.9227
Copyright © 2005-2016 RacingJunk.com All Rights Reserved.

Designated trademarks and brands are the property of their respective owners. Use of this Web site constitutes acceptance of the RacingJunk.com
Terms of Use, Classifieds Disclaimer, Privacy Policy, and Cookie Policy