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post #1 of 18 (permalink) Old 02-12-2011, 07:32 PM Thread Starter
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push rods and rocker arms

While rotating the motor trying to find my "click",
I noticed that one of my pushrods has a point in its travel where there is no tension at all. and I am able to lift it up and down between lifter and rocker arm a good 1/16 of an inch or so.
Bad rocker arms?
(I have replaced as new just about everything in this motor)
thanks as always
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post #2 of 18 (permalink) Old 02-12-2011, 07:51 PM
 
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I think you may have adjusted your rockers incorrectly. Who made your cam and lifters?
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post #3 of 18 (permalink) Old 02-12-2011, 08:15 PM Thread Starter
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post #4 of 18 (permalink) Old 02-12-2011, 08:29 PM
 
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I have never used Crower before in a car. Motorcyle yes, but car no. What I think you need to do is read the instructions for adjusting your rockers arms again. Start at the beginning and readjust all of your rockers as per instructions.
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post #5 of 18 (permalink) Old 02-12-2011, 09:02 PM
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Originally Posted by Topkat View Post
While rotating the motor trying to find my "click",
I noticed that one of my pushrods has a point in its travel where there is no tension at all. and I am able to lift it up and down between lifter and rocker arm a good 1/16 of an inch or so.
Bad rocker arms?
(I have replaced as new just about everything in this motor)
thanks as always
Sounds like adjustment to me too, Top. The "best" way to do it is to follow a procedure Mr. P-Body espouses because that will result in a consistent preload across all 16 lifters. If perchance you've already filled/soaked the lifters in oil, then you'll probably want to use the alternate method.
To do it right, you'll want both valve covers off and a way to turn the motor over with a wrench, using the crank bolt. Start with cylinder #1 (front, driver's side) and turn the motor until you see the exhaust valve just beginning to open. Adjust the intake valve for cylinder #1. The "old" way is to tighten the rocker nut just until you've taken all the slack out of the pushrod - i.e. - you can't move it up and down. Then tighten the rocker ball nut an additional 1/4 to 1/2 turn (the specific amount isn't as important as doing 16 exactly the same). Turn then engine over about 90 degrees until you see the exhaust valve for #8 just starting to open --- adjust #8 intake the same way. . The "new" way is to use a dial indicator and tighten the rocker nut to depress the piston inside the lifter a specific amount (I forget the distance, but maybe Mr. P will be along shortly.) Lather, rinse, repeat adjusting all the intake valves in firing-order sequence 1-8-4-3-6-5-7-2. You'r half done at this point. Now turn the motor over until you see #1 intake valve open all the way and just starting to close. Adjust the exhaust valve for that cylinder the same as you did the intake. Work your way ariound again, setting each cylinder's exhaust valve just after you see the intake beginning to close.

There's another sequence that lets you do two valves at once, but it can get you "off" especially if you've got a longer duration cam with a little attitude. Doing all 16, one at a time, through two complete engine revolutions is always better an more consistent.

What you're accomplishing by watching for the exhaust valve beginning to open, is making sure that the intake valve is fully closed and the lifter on the base circle of the cam. Likewise, when the intake is just beginning to close you know the exhaust is fully closed and the lifter on the exhaust lobe base circle.

Bear

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post #6 of 18 (permalink) Old 02-13-2011, 08:31 AM
 
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thanks Bear was just getting ready to post about Mr.P-bodys procedure, will be getting the engine in and fired up in the next few weeks. Are you ready for paint? Man these 66-67 bodies are a chore to get straight, with their 7' long rear quarters. I have sanding blocks from 1-4'. i will be priming w/high build for my final blocking down to 180 and wet sanding as soon as our weather allows me to get the body temp up over 50 degrees. I am hoping to spray color in April, I have found a downdraft spray booth to rent for color/clear.....spring is looking good for a debut....
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post #7 of 18 (permalink) Old 02-13-2011, 02:11 PM Thread Starter
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I removed the drivers side rocker arms. rotated the motor and the pass.side was making a "click" .
removed them all and the noise stopped.
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post #8 of 18 (permalink) Old 02-15-2011, 06:15 AM Thread Starter
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I did indeed pre soak the lifters.
The book says to torque the rocker arm nuts to 20lbs
is that out the door with the procedure you described?
thanks again
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post #9 of 18 (permalink) Old 02-15-2011, 08:53 AM
 
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Quote:
Originally Posted by Topkat View Post
I did indeed pre soak the lifters.
The book says to torque the rocker arm nuts to 20lbs
is that out the door with the procedure you described?
thanks again
it could be this. some aftermarket cams have a low cut heel that makes it impossible to adjust the valves with the stock nuts. if you have tightened the stock bottoming nuts correctly and you have slack in the pushrods you either need to use adjustable nuts or get custom pushrods to achieve the correct valve adjustment.
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post #10 of 18 (permalink) Old 02-15-2011, 09:51 AM
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I did indeed pre soak the lifters.
The book says to torque the rocker arm nuts to 20lbs
is that out the door with the procedure you described?
thanks again
Hey Top,
That "torque to 20" proceedure will work only with all factory parts in 'like new' condition. If anything in the valve train is non-factory, or if the rocker-ball nuts (or studs) are worn a little, it's not reliable. It helps to understand what you're trying to do --- and that is to remove all the "slack" from the lifter to the push rod to the rocker arm to the valve stem when the lifter is on the cam 'base circle' --- at minimum lift in other words, then take out "just a little more" in order to depress the internal spring inside the lifter that supports the pushrod cup "just a little bit". If the lifters haven't been pre-filled, then you can get them all "dead on" using a dial indicator and Mr. P-Body's proceedure. If they have been pre-filled, then you can get them very close using the proceedure I described -- take out all the slack, then tighten the rocker ball nut (or poly-lock, if that's what you have) an additional 1/4 to 1/2 turn (and lock it down, if it's a poly-lock). Very important to make sure each lifter is on the cam base circle when you adjust it. That's why you follow the proceedure I described earlier - doing all the intakes first, in firing order sequence, then the exhausts in firing order sequence. You'll rotate the engine through 4 complete revolutions, 90 degrees at a time --- 2 rev's for the intakes, 2 rev's for the exhausts.

Side note: If you're using the factory rocker ball nuts, and after following the procedure they don't "hold" their adjustment, then either the nuts, the studs, or both are worn and need to be replaced. If that happens, just go to poly-locks and be done with it.

Bear

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