Timing Components: Fundamentals and Basics

OBSERVING PISTON TO VALVE RELATIONSHIP




Remove Valve Cover
This will allow your to observe the position of the valves. Each valve is opened as the lobe on the camshaft rotates around and contacts the rocker and pushes the the valve downward against the spring pressure.

Remove Spark Plugs and Observe Pistons
On a V-6 engine positioning the crankshaft at 45 degrees before #1 Top Dead Center should place all pistons at a safe distance from the valves. View all pistons through the spark plug holes and verify that no piston is at or near top dead center.

WARNING: Never rotate the crankshaft so that a piston reaches top dead center while its associated valves are at or near their fully open position. Carefully observe valve and piston positions and if necessary alternately rotate the camshaft and crankshaft.