What is a good lobe separation angle?
Some engine specialists refer to it as that 106 sound—the NASCAR and short track oval sound where preferred lobe separation is usually specified between 104 and 106 degrees. The primary function of narrow lobe separation is to impel urgent acceleration off the turns when the throttle is opened.
How does lobe separation affect performance?
“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.
Does Valve Lift affect idle?
LSA and Lift affect the “sound” and idle quality. Generally, smaller lobe separation angles cause an engine to produce more mid-range torque and high RPM power, and be more responsive, while larger lobe separation angles result in broader torque, improved idle characteristics, and more peak horsepower.
How do you calculate lobe separation angle?
To check your LSA you calculate it by adding the intake and exhaust Lobe Centerline figures together and dividing their sum by two (Ex: 112 intake Centerline + 116 exhaust Centerline = 228 / 2 = 114-degree LOBE SEPARATION ANGLE).
What does lobe separation mean on a cam?
Definition & Description The Lobe Separation Angle (LSA) is the distance between the centerlines of the intake and exhaust lobes on the camshaft. It is measured in degrees of camshaft rotation.
What does changing the cam do?
Adjusting the camshafts so the cams are slightly ahead or behind will alter the engine’s performance. Advancing the timing will cause the fuel intakes to open and close earlier, which improves low-end torque. Conversely, retarding the cam will improve high-end horsepower at the expense of low-end torque.
What does LSA do to a cam?
Airflow and LSA A wider LSA moves intake- and exhaust-valve events farther apart and creates less overlap, which hurts intake-wave tuning. “When you’ve properly tuned a performance motor, you create high- and low-pressure waves in the intake and exhaust that help cylinder filling,” said Comp Cams’ Billy Godbold.
What is lobe centerline angle?
First let us define the lobe centerline angle. In simplest terms it is the angle between the intake and exhaust lobe peaks. The LCA dictates two important valve timing attributes: valve overlap around TDC, and how much intake or exhaust valve closure delay there is past the end of the relevant stroke.
How is the lobe separation angle of a camshaft chosen?
Selecting a camshaft for a given engine’s purpose usually involves a compromise between low- or high-end power options, and the lobe separation angle (LSA) is one of those factors where engine builders have to make a choice between those priorities.
Which is better wide or narrow lobe separation?
Typically, narrower lobe separation develops peak torque at lower rpm and widening the separation tends to build peak torque higher in the rpm range. Nitrous engines, which make plenty of power and torque, often run wide lobe separation angles to moderate cylinder pressures and temperatures. Engine builders Chuck Lawrence, left, and Doug Patton.
How does the LSA affect the torque band?
So the wider LSA introduces a broader and therefore longer torque band.” “Changing the lobe separation angle changes the amount of overlap that exists during the time the intake and exhaust valves are both open,” echoes Doug Patton of Pro Line Race Engines.
Why do nitrous engines have wide lobe separation angles?
Nitrous engines, which make plenty of power and torque, often run wide lobe separation angles to moderate cylinder pressures and temperatures. Engine builders Chuck Lawrence, left, and Doug Patton. “Lobe separation angles,” he continues, “are influenced by the camshaft grind.