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Just adjusted the valves on my 350. Started at cylinder #1 at TDC on the compression side. Adjusted that cylinder then moved crank 90 degrees then adjusted cylinder #8 then moved crank 90 degrees then next cylinder in firing order did this until all valves where adjusted. My question is when setting the lifter preload some of the rocker arm nuts
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would only tighten 1/2 a turn all the way and some would go 3/4 of a turn. Will this be an issue later on. Some guys on another site say 1/2 turn is ok. Also with type of rocker nuts I have they say have to adjust the sets screws. What should I do ? Picture us of one of the rocker arms and nuts.
 

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Are you saying that your nuts were bottomed out on the studs so that there was no way to tighten them further? If so, something is wrong. You should have lots of adjustment room there. From that camera angle those LOOK to be the type that uses a center set screw.
 

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Deputy Director, Region 3 PA (west)
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I know the service manual says 1 turn after the rocker arm contacts the pushrod, but it's been common for years to set 'em about 1/2 turn to extend the rpm range a bit. I've done the 1/2 turn on many SBC's for many years without any issues. I've never seen or used that type of nut, but I've done the same specs on various billet and roller rockers, again without issues.

Bill
 

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Just adjusted the valves on my 350. Started at cylinder #1 at TDC on the compression side. Adjusted that cylinder then moved crank 90 degrees then adjusted cylinder #8 then moved crank 90 degrees then next cylinder in firing order did this until all valves where adjusted. My question is when setting the lifter preload some of the rocker arm nuts View attachment 139417 would only tighten 1/2 a turn all the way and some would go 3/4 of a turn. Will this be an issue later on. Some guys on another site say 1/2 turn is ok. Also with type of rocker nuts I have they say have to adjust the sets screws. What should I do ? Picture us of one of the rocker arms and nuts.
"would only tighten 1/2 a turn all the way and some would go 3/4 of a turn."
That makes no sense. Are you loosening the lock nut inside the adjusting nut and backing off the adjusting nut until you can spin the pushrod before you try to set the lash at 1/2 turn? There's nothing wrong with 1/2 turn but if you can only turn the adjusting nut 1/2 turn you are doing something wrong or you have some collapsed lifters.
 

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Loosen nut, back out center lock 1 turn, then tighten nut while spinning push rod with your fingers, when you feel resistance then go 1/2 to 3/4 turn from that point, tighten center lock. I use a clear distributor cap so I can do the valves in the firing order when both valves for each cylinder are closed. Hard to make a mistake with this method.
 

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1986 Elcamino 305 4bbl
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as a check ; All nuts should end up at the same height, put a straight edge across the tops and look for any gap. Every cylinder should be the same, whether its piston weight, valve seat width, plug gap or rocker arm stud.
More than .020" - i would check the stud height without nuts on & same method. if a stud is pulled it'll show up this way.
When finding zero lash wiggle push rod sideways instead of up & down, just get close, you can feel it n the rocker. i've had alot of mechanics goto far and bottom the lifters out.
Add 1/2 turn. its done. i run the high volume oil pump, so for my engines i go with 1/4 turn, and thats still way more oil pumping thru pushrods than needed.
From GM service Manual;
#1 at TDC you can adjust exhaust 1,3,4,8 & intake 1,2,5,7

rotate 360 degrees #6 at TDC adjust exhaust 2,5,6,7 & intake 3,4,6,8

This applies to any chevy engine with standard firing order 18436572 , small or big block!
 
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