What is a good camshaft duration?

Measuring duration at 0.050-inch tappet lift has become standard with most high-performance cams. Most engine builders feel that 0.050 duration is closely related to the rpm range where the engine makes its best power.

What is intake duration?

Intake Duration at . 050 inch Lift – The number of degrees the crankshaft moves while the intake valve is open. Cam manufacturers agreed to measure and give camshaft duration based on the lifter moving . 050 inches. This made duration numbers easier to compare between different cam manufacturers.

What is cam lift and duration?

Lift and duration are the primary factors that determine a cam’s profile. Lift is the amount a cam lobe actually moves a valve off its seat and is measured in fractions of an inch. Duration is the amount of time a cam keeps a valve off of its seat, measured in degrees of crank rotation.

What gives a cam a lopey idle?

For the low-buck street guy to get a lopey idle and see an increase in power without a drastic decrease in driveability, he needs a cam with a lobe-separation angle of 110 degreesthe same lobe lift as recommended earlierand duration numbers of about 218 degrees at .

What is cam duration mean?

DURATION: Duration is how long the cam holds the valves open. It’s expressed in degrees of crankshaft rotation (remember, the cam rotates at half the speed of the crank). A 280-degree-duration cam holds the valves open longer than a 260-degree-duration cam.

What makes a camshaft choppy?

Registered. LSA (lobe separation angle) determines the choppiness, it has to do with the overlap of when both valves are open, as in when the exhaust valve is closing and the intake valve is opening to pull fresh fuel in on the intake stroke after pushing out the burnt fuel. Most GM cams come on a 112, 114 or 116 LSA.

What gives a cam a choppy idle?