While you’re fine tuning the details a Small Block Chevy engine build, you’ve got to do a little work up top to get the engine running correctly. Properly adjusting each pushrod guideplate is vital for ensuring valvetrain stability. August Cederstrand from Edelbrock is your guy for getting this simple, yet important, part of any build right.
The guideplates in your valvetrain have the simple job of keeping your engine’s pushrods aligned in order to actuate the rocker arm, and keep the rocker arm stable while it follows its arc. Guideplates are needed to in most high-lift, high-pressure uses, especially if the geometry of the valvetrain has been changed in any way after you modify your cylinder heads. It’s this geometry that’s key in ensuring a long life of your engine, so taking this little step to protect and correct it is worth the time. Another thing to note is that guideplates are made from hardened steel for durability, and in order to keep the guideplate from eating through the pushrods, you need to use hardened pushrods.
Adjusting the guideplates is an easy chore. Once your cylinder heads are installed on the block, you need to set your engine to top dead center on the compression stroke for the cylinder you are adjusting. You then loosen the rocker arm studs, just slightly, so the guideplate can be moved, but isn’t so loose that it’s completely out of position around the stud. From here, you’re going to slide the rocker arms onto to the studs, and then tap the guideplate into position.
As August shares, there needs to be at least .005” of clearance between the pushrod and wall of the hole in the cylinder head. Once the clearance is where it needs to be, remove the rocker arm from the stud, and tighten the stud down with a torque wrench to spec. Then install the rocker arms onto the studs, making sure the tips of rocker arms are centered above the valve stems. Check the alignment of the guideplate, and move on to the next.
Shawn Henry is a Texas native who has spent the majority of his career building and selling F-Bodies and Corvettes. Now studying journalism, he is taking a new direction with his love of performance vehicles.
