Timing – Info

Effect Of Changes In Cam Timing
Advancing	Retarding
Begins Intake Event Sooner	Delays Intake Closing Event
Open Intake Valve Sooner	Keeps Intake Valve Open Later
Builds More Low-End Torque	Builds More High-RPM Power
Decrease Piston-Intake Valve Clearance	Increase Piston-Intake Valve Clearance
Increase Piston-Exhaust Valve Clearance	Decrease Piston-Exhaust Valve Clearance
Effect Of Changes In Lobe Separation Angle (LSA)
Smaller LSA number/ degrees	Larger LSA number/ degrees
Moves Torque to Lower RPM	Raise Torque to Higher RPM
Increases Maximum Torque	Reduces Maximum Torque
Narrow Power band	Broadens Power Band
Builds Higher Cylinder Pressure	Reduce Maximum Cylinder Pressure
Increase Chance of Engine Knock	Decrease Chance of Engine Knock
Increase Cranking Compression	Decrease Cranking Compression
Increase Effective Compression	Decrease Effective Compression
Idle Vacuum is Reduced	Idle Vacuum is Increased
Idle Quality Suffers	Idle Quality Improves
Open Valve-Overlap Increases	Open Valve-Overlap Decreases
Closed Valve-Overlap Increases	Closed Valve-Overlap Decreases
Natural EGR Effect Increases	Natural EGR Effect is Reduced
Decreases Piston-to-Valve Clearance	Increases Piston-to-Valve Clearance
CAMSHAFT GEOGRAPHY AND LOBE FUNCTION
1) Max Lift or Nose
2) Flank
3) Opening Clearance Ramp
4) Closing Clearance Ramp
5) Base Circle
6) Exhaust Opening Timing Figure
7) Exhaust Closing Timing Figure
8) Intake Opening Timing Figure
9) Intake Closing Timing Figure
10) Intake to Exhaust Lobe Separation