A "Trick" Question..whaddya'll think? | FerrariChat
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A "Trick" Question..whaddya'll think?

Discussion in 'Technical Q&A' started by 335s, Mar 20, 2014.

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  1. 335s

    335s Formula Junior

    Jan 17, 2007
    870
    SF Bay Area
    Full Name:
    T. Monma
    #1 335s, Mar 20, 2014
    I was recently stunned when I observed an engine's head's being assembled by a "professional" engine builder(a "performance" oriented establishment as well), and observed somthing which prompted me asking why he was NOT doing a procedeure-call it x, y and z for arguements sake-in what I considered a time honored fashion...he stated that I was crazy, that it maked no difference, and that force was force and not directional, that spring co-efficients are NOT a factor-as these arn't "behives" of progressive wound springs...

    The question I'fd like a polled response from readers: Is there a "proper" way to install your valve springs? In other words: is there a top and a bottom to your valve springs-both inner and outer-how do you identify it, what is it, and how do you install the springs-"rightside up"-IF SUCH AN ORIENTATION EXISTS?{this IS a trick question-anmd I DO know the answer, being a racing car engine machinist and builder}
    And, WHY is it important?
     
  2. James_Woods

    James_Woods F1 World Champ

    May 17, 2006
    12,755
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    James K. Woods
    #2 James_Woods, Mar 20, 2014
    What exactly was the point of this thread, except to proclaim from the hills how much you seem to think you know about Valve Springs?
     
  3. JCR

    JCR F1 World Champ
    Silver Subscribed

    Mar 14, 2005
    10,898
    H-Town, Tejas
    #3 JCR, Mar 20, 2014
    Last edited by a moderator: Sep 7, 2017
    Where the coils are closer, this side should face the cylinder head (stationary side). Not important at low RPM but helps combat valve float and spring surge at high RPM. You want less mass on the moving side (top) where the retainer is located.

    https://www.youtube.com/watch?v=yfmb-tCo2yA
    Image Unavailable, Please Login
     
  4. smg2

    smg2 F1 World Champ
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    Apr 1, 2004
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    SMG
    #4 smg2, Mar 20, 2014
    I agree, strange to ask a question you already know the answer to.

    However the answer is not a cut and dry thing. Not all springs are the same, some of the Ferrari valve springs have the same pitch on both ends. Other mfgs have a 'progressive' pitch where the coil pitch is closer on the bottom. So if for example the heads were to a 308, then it indeed would not matter which end was up.

    This all due to the camshaft lobe ramp rate and jerk, shank and nose over force etc..
     
  5. James_Woods

    James_Woods F1 World Champ

    May 17, 2006
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    James K. Woods
    #5 James_Woods, Mar 21, 2014
    Camshaft jerk.

    This is the answer.
     

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