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Adjusting the valves on my '81 Chevy 305

Discussion in 'Chevy Trucks' started by Wally3128, May 21, 2002.

  1. Wally3128

    Wally3128 Junior Member
    Messages: 28

    Looking for help on adjusting the valves on my '81 Chevy 305.
    The harmonic balencer is pulled around to 0' and the rotor is ALWAYS pointing at the #8 plug wire. I had the cam replaced at 75k now 140k. Little buba was riding around and hit a pole! The valves have been raddling ever since. We stoped running it and I am atempting to get the raddle out of it. #4 exhaust rocker seems to be dry on top. I have NEVER done this before but have read the article on this web site. But... I can't get this thing to TDC on #1! Help Please!!
    Thank you:confused:
     
  2. Power mad

    Power mad Member
    from Oregon
    Messages: 75

    Hm I'll try to make this easy to understand, it is easier for me to show but here goes.
    There are prolly 2 dozen ways to adjust valves everyone has their own way of doing it.
    The way I adjust valves on a fresh cam is to do it with out the engine running.
    I use the exhaust opening intake closing method.
    That is on a cylinder bank I adjust the intake when the exhaust is starting to open and vice versa.
    I tighten the nut until there is 0 lash and then I go a 1/4 turn more, some go a 1/2 turn.
    On an engine that has already gotten a broken in cam and a valve or 2 needs adjusted I warm the engine up to operating temp and pull a valve cover off and clip on my splash sheilds.
    then I start the engine and starting from front to back I loosen the rocker nut slowly until it starts to clack and then tighten it until it just goes away, then I give it a slow 1/4 turn more.
    All of the rockers should have oil coming from them.
    If not then there is something wrong and further work will be required,
    Start with removing the push rod to see if is plugged up.
    If not then there is proly something wrong with the lifter.
    As far as the rotor pointing at #8 at TDC that is about right.
    If you check the timing with a light and record where it is at which is prolly around 6 deg BTDC.
    Then when ya roll the engine to 6 deg BTDC for #1, the rotor will be at # 1 on the distrubutor.
    The engine fires at 6 deg BTDC (if that is what the timing is set to)
    Then continues on, when the timing mark hits TDC the rotor has already fired the #1 cylinder and is moving on to the next one which is #8.
    I hope that clears it up some for ya.
    :)
     
  3. TurfPlus

    TurfPlus Senior Member
    Messages: 179

    I'd also check #4 push rod to make sure its not clogged and the rocker arm and ball is not worn from running dry. If so replace them.