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Thread: valvetrain question

  1. #1
    Thank you from BT Master Mechanic
    Join Date
    Feb 2006
    Location
    Twin Falls, ID
    Posts
    332

    valvetrain question

    I had what i thought was excessive lifter tap until i pulled a valve cover and discovered my rockers, pivots, and pushrods were in desperate need of replaceing. Some were extremelly worn, but the worst of them was on the exhaust side of each cylinder. On most of them, the oil grooves on the pivots were completely gone and the pushrods were missing quite a bit of material at the top end. The intake assemblies didnt look near as bad.

    Question is, what caused this? A timing issue where the exhaust valve is trying to open late on the upstroke of the piston...and is therfore under more pressure then normal causeing excessive wear on that particular set of components?

    .....Or is it just normal for the exhaust side to wear more then the intake side (i really dont buy that)

    on the upside, after replaceing the entire set of rockers and pushrods, the engine runs baby-smooth...no more lifter tap.
    401cid, T18a/D300 twinsticked.
    Lifted, locked, and Swampered

    "Its flat here...real flat. And the locals smell like potatoes."

  2. #2
    Thank you from BT Master (OIIIO)
    Join Date
    Oct 2006
    Location
    Virginia
    Posts
    771
    I had a similar situation with a 360 that I got for $150... most if not all of the Exhaust pivots etc were worn... a few intakes... but it had a lot of miles on it.

  3. #3

    Join Date
    Jun 2006
    Location
    '69 AMX 12.60@107 - Ohio, unfortunately (:-P)
    Posts
    942
    Heat causes more excessive wear on exhaust valvetrain than intake ?

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