Pushrod engines; hydraulic lifters and valve lash settings

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Getting ready to adjust valves on the old hot rod truck, I've been hearing a tapping noise from passenger side valve train area. Pretty sure I had a lock nut come loose on the roller rocker...

I've always done a half turn after achieving zero lash using the old "spin the pushrod" technique. Ford, chevy, whatever it is, always done a half turn.

Some guys say quarter turn, full turn, I've heard "1/8th turn for racing," etc.

I'm not asking for advice here, just wondering what others do, and why this seems to be a never ending debate among hot rodders. If you ask 10 people you will get 10 answers
 
On my small block Chevy, I spin the pushrod while tightening down the rocker arm nut until I can't spin it anymore (that's assumed to be zero lash), then go an extra 1/2-turn. The Chevy Power manual describes a method where the engine is run with all the valves adjusted using the basic method, and back off each nut until you hear the lifter tick, then tighten down the nut until the lifter stops ticking. This is called "zero lashing". Other engines may use different methods because they are constructed differently.
 
I've always set them at .030 and use a dial indicator at the lifter plunger. Also, when using a rocker nut with a setscrew, I finish the adjustment while turning both at the same time so they won't come loose.
 
On the 351 Cleveland, I torque the rocker arm bolts to the torque spec. Ford had a better idea.
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On my Holden 6s (that used the chev arrangement), I did the running adjustment once, and once only.

After that used the finger twist and 1/8 turn...I used to rev those REALLY hard, and didn't want "pump up".
 
We used to do them running - oil everywhere. Back off until they clack, then down 1/2 or 3/4 turn...there was usually a spec.
 
Originally Posted By: Merkava_4
On the 351 Cleveland, I torque the rocker arm bolts to the torque spec. Ford had a better idea.
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My 66 389 is the same but too many variables make it not very accurate, i.e. deck mill, head gasket thickness, valve stem height and rocker ratio. Much easier to make them adjustable.
 
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