How to Adjust the Valve Lash on a Small Block Chevy
- 1). Start the engine and run it until it reaches operating temperature on the temperature gauge. As the engine heats up, the parts in the valve train expand slightly. It is important to make valve lash adjustments with the engine warm to prevent unwanted binding when the engine is hot.
- 2). Turn the engine off. Remove the valve cover bolts using a 3/8-inch socket and ratchet on edge mount valve covers or a 10 mm socket and ratchet on center bolt valve covers. Lift the valve covers off the cylinder heads and lay them aside.
- 3). Start the engine. Slip a 5/8-inch socket and ratchet onto the lock nut in the center of the rocker arm of the first valve on the cylinder head. Loosen the nut, by turning it counterclockwise with the socket and ratchet, until it clicks noticeably. Tighten the nut slowly, by turning it clockwise, until the clicking noise goes away. Turn the nut 1/2-turn further.
- 4). Allow the engine speed to stabilize. As the valve lash is tightened, the engine speed will drop noticeably. Work slowly and allow the speed to stabilize to prevent stalling of the engine. Repeat the procedure for the remaining 15 valves in the engine.
- 5). Remove the old gaskets from the valve covers using a scraper to remove stubborn parts of the gasket. Reinstall the valve covers using new gaskets. Tighten the valve cover bolts snugly.
