What I Learned Today With Jeff Smith — Rocker Bolt Torque Sequence

With stock LS engines using stock or near-stock spring loads, the following technique is not really necessary. But for high-RPM LS engines with heavier spring loads — especially those using dual valve springs — you need to be aware of the load applied to each rocker bolt. This technique simplifies rocker arm installation, eliminating both the need for tracking individual cam lobe positions as well as the need to rotate the engine several times per cylinder with the EOIC method we talked about in a previous article that can be read here.

The first step of this technique is to install all the rockers and all the rocker bolts merely finger-tight. There will generally be at least three or four rockers on each head where lift is currently being applied by its respective cam lobe. You can easily tell which rockers are not under load by spinning or wiggling the pushrod by hand.  Torque all the rockers where there is no cam lift to the requisite 22 lb-ft, and then turn the crankshaft over 180 degrees.

The “Exhaust Open, Intake Closed” method of setting valve lash can also be used to accomplish the goal of tightening the rocker bolt with the least amount of pressure on the rocker arm, but this method is much simpler.

Since the cam spins at half speed, that will only rotate the cam 90 degrees, which should put additional cylinders on the base circle of their respective cam lobes. You can then identify the loose rockers and can then torque these rocker bolts in place. Repeat twice more, and then give all of the bolts a torque check, and you’re all set.

This technique reduces the load on the top portion of the aluminum threads while fastening the bolts into the head, while eliminating the need to remember any firing order, and reducing the number of times you need to rotate the engine. With these smaller metric fasteners used on the LS, this might just save you from pulling the threads out while installing rocker the rocker arms.

About the author

Jeff Smith

Jeff Smith, a 35-year veteran of automotive journalism, comes to Power Automedia after serving as the senior technical editor at Car Craft magazine. An Iowa native, Smith served a variety of roles at Car Craft before moving to the senior editor role at Hot Rod and Chevy High Performance, and ultimately returning to Car Craft. An accomplished engine builder and technical expert, he will focus on the tech-heavy content that is the foundation of EngineLabs.
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