What is cam duration and lift?
Duration is how long the valve is off its seat. It is listed in degrees of crankshaft rotation. When someone refers to a “big cam,” they mean it has longer duration, not higher Lift. Advertised Duration is the degrees of crankshaft rotation that the lifter is raised more than a predetermined amount.
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.
Does camming a car make it faster?
Method 2 of 2: Maxing Engine Performance. Consider installing a performance camshaft. Performance cams increase the duration and timing of the valve openings during the engine stroke, increasing horsepower and making your car accelerate more quickly.
Why does the duration of a camshaft increase?
Increasing duration allows more air in & out, and so does increasing your maximum lift (the former increases the size of the valve opening while the latter simply increases the amount of time that opening is open). A lot more goes into determining a cam’s maximum lift (or rate of valve opening) than does its lobe timing, though.
What’s the difference between cam lift and duration?
The final cam spec to understand is lift. While duration refers to how long the valve is opened, cam lift is used to determine how wide the valve is opened. If the valves are not opened wide enough, they will cause a restriction for the air trying to enter or exit the cylinder.
What does the duration of a big cam mean?
Duration is how long the valve is off its seat. It is listed in degrees of crankshaft rotation. When someone refers to a “big cam,” they mean it has longer duration, not higher Lift. Manufacturers often list 2 different duration values:
What do you need to know about cam specs?
When it comes to performance parts, understanding cam specs and their affects will help you select the best cam for your specific engine. The four important camshaft specs to understand are duration, centerline, separation and lift. DURATION Duration refers to how long a valve is opened in relation to crankshaft rotation.
Why are cam lift duration and cam lift important?
Where cam lift and duration describe the effect of each lobe on a valve. Cam Lobe Separation is an important performance characteristic because it times the intake and exhaust valves. If the Lobe Separation angle was 0 degrees, both intake and exhaust valves would be opened and closed at the same time.
How is intake duration determined in a camshaft?
The first two events determine the intake duration (closing minus opening), which is built into the camshaft. The exhaust opening and closing are the next most important parameters. The exhaust lobe is fixed relative to the intake lobe by the lobe separation angle.
Duration is how long the valve is off its seat. It is listed in degrees of crankshaft rotation. When someone refers to a “big cam,” they mean it has longer duration, not higher Lift. Manufacturers often list 2 different duration values:
When does the intake valve reach its maximum lift?
The intake valve reaches its maximum lift at some defined point (usually about 106 degrees) after top dead center. This is called the intake centerline, which refers to where the cam has been installed in the engine in relation to the crankshaft. This is commonly called “degreeing”. We will talk about this later also.