Camshafts


#1

Last week when I posted something here, a member got upset (and was offended that it did not challenge their intellectual and mroal superiority). Criticism is fine and constructive criticism is encouraged. Here is a list that floats around the web giving some hints on camshaft basic traits. Consider it a starting point, and if you have something better or can explain things more eloquently, then please do add to the info base.

VARYING LOBE SEPARATION ANGLE
…Tighten ……………………………………. Widen
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

LOBE SEPARATION ANGLE
Above 114 Deg. = Extremely Wide
114-112 Deg. = Wide
112-110 Deg. = Moderately Wide
110-108 Deg. = Moderate
108-106 Deg. = Moderately Tight
106-104 Deg. = Tight
Below 104 Deg. = Extremely Tight

ADVANCING / RETARDING CAM TIMING
…ADVANCING ……………………………… RETARDING
Begins Intake Event Sooner ………………. Delays Intake Event Closes Intake
Open Intake Valve Sooner …………………… Keeps Intake Valve Open Later
Builds More Low-End Torque ………………. Builds More High-End Power
Decrease Piston-Intake Valve Clearance …. Increase Piston-Intake Valve Clearance.
Increase Piston-Exhaust Valve Clearance … Decrease Piston-Exhaust Valve Clearance

Extra info

https://tighecams.com.au/cars.htm

For a camshaft glossary of terms

https://tighecams.com.au/camtypes.htm