Camshaft lobe lift is the amount (measured in inches or millimeters) that the camshaft is capable of moving the valve train components in order to open the valves. The lobe lift is a measure of how much taller the "egg shaped'' portion of the camshaft lobe is above the base or circular portion of the shaft lobe. Lift is directly proportional to how far the valves can open. A worn camshaft (with poor lobe lift) cannot fully open the valves. The lobe lift therefore can be directly responsible for proper or poor engine performance.
Lobe lift can be measured in 2 ways, depending on what tools are available and whether or not the camshaft has been removed from the engine. A dial gauge can be used to measure the lift with the camshaft installed, while a micrometer is normally only used once the shaft has been removed from the engine.
