Diyvehiclerepair
- What is a good camshaft duration?
- What is camshaft operating range?
- What is camshaft duration and lift?
- What's more important lift or duration?
- How is total cam lift calculated?
- How does cam duration affect torque?
- How do you check the timing on a camshaft?
- How do you check camshaft timing?
- What is lobe lift?
- How does cam lobe separation work?
- How does the shape of the camshaft lobes affect valve timing lift and duration?
What is a good camshaft duration?
A 280-degree-duration cam holds the valves open longer than a 260-degree-duration cam. Holding the valves open longer allows more air and fuel into the engine and also allows more to get out through the exhaust. Longer duration (higher number) improves top-end power but almost always sacrifices low-end torque.
What is camshaft operating range?
Definition & Description. The basic operating rpm range for a camshaft is its "sweet spot." This range is where the engine will produce the most Torque and Horsepower.
What is camshaft duration and lift?
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's more important lift or duration?
Designing a cam profile with more lift results in increased duration in the high-lift regions where cylinder heads flow the most air. Short duration cams with relatively high valve lift can provide excellent responsiveness, great torque, and good power. But high lift cams are less dependable.
How is total cam lift calculated?
Simply measuring the diameter of the base circle, and subtracting that from the largest diameter of the cam, the lobe lift, will calculate the lift of the cam.
How does cam duration affect torque?
Duration has a marked affect on the cams power band and drivability. Higher durations increase the top-end at the expense of the low end. As a general rule, cams with 220-235 degrees of duration tend to produce good low end torque.
How do you check the timing on a camshaft?
To find exact TDC, first set the dial indicator to zero at the point of highest piston travel. Next, turn the crankshaft counterclockwise about 90 degrees. Then, slowly rotate the crankshaft clockwise (the normal direction of engine rotation) until the indicator is . 030" below the TDC (zero) setting.
How do you check camshaft timing?
To confirm accuracy, you need a dial indicator with a measuring range of at least 1 inch on each lifter. With both valves closed, set the dial indicator at zero. Begin with the intake valve; slowly turn the crank clockwise until the lifter rises 0.050 inch. Stop turning the crank and read the degree wheel.
What is lobe lift?
Lobe Lift is the amount (usually in inches) that the cam lobe increases in radius above the cam base circle. Tip: To quickly find maximum lobe lift, measure the base circle of the cam and subtract it from the thickness across the cam lobe's highest point (see the diagram below).
How does cam lobe separation work?
“On a naturally aspirated engine, the lobe separation angle has an effect on whether the engine reaches peak torque a little earlier or later in the rpm range. Typically, narrower lobe separation develops peak torque at lower rpm and widening the separation tends to build peak torque higher in the rpm range.
How does the shape of the camshaft lobes affect valve timing lift and duration?
The key parts of any camshaft are the lobes. As the camshaft spins, the lobes open and close the intake and exhaust valves in time with the motion of the piston. It turns out that there is a direct relationship between the shape of the cam lobes and the way the engine performs in different speed ranges.
