What is Camshaft Lobe Separation?
Definition and Description
The Lobe Separation Angle (LSA) is the distance between the centerlines of the intake and exhaust lobes on the camshaft. It is measured in degrees of camshaft rotation.
How is it measured?
You can calculate the LSA using the centerlines of the intake and exhaust lobes. (This information should be listed on your Cam Card. If not, you can find them using a Dial Indicator and Degree Wheel.)
The formula for LSA is:
For example, if the intake is 107° and the exhaust is 117°:
107° + 117° = 224°
224° ÷ 2 = 112° (LSA)
How does it affect performance?
Combined with Duration, the LSA determines Valve Overlap. This overlap has a significant impact on Engine Vacuum and idle quality.
Camshafts with a "tight" LSA (106°-109°) will usually have more overlap.
Camshafts with a "wide" LSA (110°-118°) will have less overlap.
