Rocker Adjustment Problems

Michael Yount’s valve adjustment procedure

Here's an easy way to determine this. Start with the #1 cylinder. Rotate the engine with a ratchet on the crank bolt clockwise. Watch the #1 pushrods. First the exhaust pushrod will rise and fall signaling what would be the exhaust valve opening and closing if the rocker were on. As it closes the intake pushrod will rise -- keep rotating clockwise until the intake pushrod falls and is level with the exhaust pushrod - both at the same height. Both lifters are now on the base circle of the cam - both valves would be closed if the rockers were on.

Now, install both rockers. Tighten the bolts with one hand while rocking the rocker with the other hand - continue until you reach the point where you can't 'rock' the rocker any more because there's no gap on the valve stem end or the pushrod end. You are at zero lash - i.e. - no gaps. Stop tightening just as you reach this point.

Now, put your torque wrench on the bolt and tighten it to 18-20 ft-lbs while counting the number of turns it takes to reach the torque. You should hit the torque within 1/4 to 1 turn of the bolt. If it takes more than 1 turn, use a shim to raise the rocker -- each .030" shim will reduce the number of turns to torque by about 1/4 turn. If you reach the torque in less than a 1/4 turn, or you have trouble reaching zero lash even at full torque, then you'll either need longer pushrods, or to CAREFULLY remove some material from the bottom of the rocker fulcrum. Using the procedure described above, you will work through the remaining 7 pairs of rockers. If you follow the firing order, it will minimize the manual cranking you have to do to get the lifters on the base circle of the cam prior to installation of the next pair.

When I first went through mine, 13 of them took no shims; 3 of them took 1 .030" shim. Upon cranking it up, one or two of them sounded a bit noisier than I thought was right, so with the engine hot, I pulled the upper off, and the valve covers, and went through the installation procedure again. That time, 11 of them took no shims; 4 of them took one .030", and one of them took one .060" shim. And they were very quiet running.

Good luck with it.
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Michael Yount - K'ville,TN 82 Volvo 242w/5.0L; 2000 Suzuki Bandit 1200

Here's an easy way to try again. Rotate the crank until you see one of the pushrods all the way up. Any cylinder, doesnt matter. Then adjust the other valve for that cylinder (the one with the pushrod down). Point being, when the intake pushrod for a cylinder is all the way up, the exhaust valve for that cylinder is in position to be adjusted, and vice versa. Stick a piece of tape on the ones that are done and continue till they're all done.

Exactly how are you determining zero lash before you crank down the 1/2 turn for lifter preload? That's important too. I rotate the pushrod between fingers while slowly tightening the nut. The moment rotating resistance is felt, thats zero lash. Then crank your 1/2 turn.

Wait wait!!! I described the method for stud mount adjustable rockers. jrichker described the method for pedestal mount rockers.

Which type do your heads have? Stud mount or pedestal mount?

Everything I see on the web about Edelbrock 5.0 heads says they are pedestal mount. Can you post pics of how your particular rocker arm assemblies mount? Show the parts installed and the head with one not installed.

Here's the Edelbrock spec sheet indicating they are pedestal mount.
http://www.edelbrock.com/automotive/misc/tech-center/install/6000/60349.pdf

I found some with studs. Do they look like the one pictured here?
http://www.jegs.com/p/Edelbrock/Ede...320/10002/-1?gclid=CO6hqPbQmNICFVCHswodbw4E4Q

why did you change the pushrod length. did you measure using an adjustable pushrod, checker spring, and solid lifter?

I wouldn't move the lifters. They develop a wear pattern with each cam lobe. It's best to keep lifters where they have always been.