Valve Adjustments

Valves:
The first thing to do is clean the entire top of the engine off with compressed air to make sure nothing can get in the engine. Get all the tools needed for the job and assemble them on the car. Use quality feeler gauges. To help accidentally using the wrong size gauges, bend the one or two on a 45-degree angle. Take the plugs out and lay them in order so they can be return to the same cylinders when the operation is complete. Next, take off the valve covers. Put all the nuts and bolts far enough from the motor so you don't have to worry about them falling into the engine. Take a flashlight and look over the springs and any other mechanical parts very closely for any cracked or missing parts. Take the time and check everything thoroughly! After looking over the heads, bump the engine over and look at all the belts. (Make sure the car is out of gear before you do this, and fingers are clear of the belts). Look very closely for any tears or holes from rocks. It is also a good time to check if the belt is running in the middle of the pulley. Intake and exhaust valve lash settings should be written in a book, as well as on the intake. These are the cold settings. Along with the lash settings, also have spark plug gap and timing settings written on the intake. This is all good information to have nearby when things get hectic at the track.

The valve lash is always measured between the tip of the valve stem and the bottom surface of the rocker that pushes the valve. Start at the number one cylinder, which is the left side (driver's side) front of a GM engine. (On Fords number one is the front cylinder on the passenger side.) Adjust the exhaust first. Don't try to get the intake and exhaust at the top together, but rather do them one at a time. Bump the engine over until the exhaust valve (the header pipe is below this valve unless its a SB2.2) is at the top of its stroke. At the same time the intake valve should be down and just starting to come up. You will be able to wiggle the exhaust rocker, unless the setting is way too tight. You might have to turn the engine over several times until you hit it just right. Place the correct thickness feeler gauge between the rocker and tip of the valve. The feeler gauge should go in with a little bit of pressure applied. Not to easy and not too hard! The shaft mounted rockers have the adjustment screw on the push rod end. Stud mounted rockers are adjusted at the stud in the middle of the rocker. After adjusting each rocker, tighten the lock nut and check it again. If the adjustment still feels right with the adjuster locked down, you can move on to the intake valve. To get the intake valve in the right position bump the engine until the exhaust valve just begins. With many cams, the setting for the intake and exhaust valves are different so be sure you use the right feeler gauge! Continue through all the valves using the same procedures. You can also make it practice to check the valve spring pressure with a valve spring gauge. This is a good way to see if your springs are getting soft, or if you have a broken or cracked spring. When you have completed setting all the valves, check all the adjusters one more time. Now is a good time to check the header bolts since they are often more accessible with the valve covers off and spark plug wires out of the way. Next, reinstall the spark plugs. If you have aluminum heads put a small amount of never-seize on the threads to make them easier to remove next time. Attach the plug wires making sure they are on the right plugs (a very common mistake, especially when in a hurry) and hear them snap. Then check the top of the heads once more for anything that is not supposed to be in there. Put the valve covers on. If you do not already know the correct torque settings for everything, including header bolts, rocker studs etc., get a list from your engine builder.