Camshaft existence may be one of the most meaningful determining factors in ample block Chevy performance, on the other hand it is even matchless one of the indefinite elements of a cam's draw that wish carefulness. Some others are valve lift, lobe separation angle, and intake/exhaust centerlines, among others. A long-duration cam is not necessarily pathetic, on the other hand also much duration can be.
Camshaft Duration
They move the effective power band higher, and produce less lower-speed power.
Tip/Warning
When seeking higher performance levels, many people select camshafts that too aggressive---the engine becomes difficult to operate unless other modifications are incorporated in their upgrade.Manufacturers don't use consistent methods to mirror this period, and so another specification is used---"duration at .050 inch" lift.
Duration at .050-inch Lift
Combined with advertised duration, a measurement at .050 inch of lift gives all camshafts a better baseline for which to symbolize duration. It also can help indicate how aggressively/quickly the lobe is opening a valve. Some cam designers also report lift at .020-, .050- and .200 inch lift.
Short-Duration Cams
These cams are similar to standard performance production engine cams; they have an effective lower RPM power range and aren't designed for maximum higher RPM power. They idle smoothly, are reliable and offer few maintenance issues.
Long-Duration Cams
Cam lobes designed with long durations are oriented for high RPM, high performance applications.The expression "life" is used to denote how many degrees of crankshaft rotation (a margin of period) that a valve is extensive and is the valuable determining cause at what RPM scale the engine produces capability.
Advertised Duration
This quantity, "advertised", is the stop at which the cam lobe begins to unbolted a valve.Also, with too much duration and lift, pistons and valves may contact each other and cause serious internal damage.
