Lobe Separation Angle Calculator

Lobe Separation Angle (LSA)

Lobe Separation Angle (LSA) is the angle, measured in camshaft degrees, between the peak (centerline) of the intake lobe and the peak of the exhaust lobe. This value is ground into the camshaft during manufacturing, which means it directly affects how your engine breathes, idles, and builds power.

The standard formula used by engine builders is:

LSA = (Intake Centerline + Exhaust Centerline) / 2

For example, if your intake centerline is 106° and your exhaust centerline is 118°, the LSA becomes 112°.

LSA defines how much valve overlap the camshaft has, how quickly the engine revs, and what kind of performance curve it produces. That’s why tuners, mechanics, and race engine builders rely on it when configuring engines.

Why LSA Matters in Engine Performance

LSA controls how aggressively your camshaft behaves. Even a small change in LSA can drastically affect engine characteristics.

1. Valve Overlap

LSA strongly influences overlap — the time when both intake and exhaust valves remain open.

• Narrow/Tight LSA (106°–110°): More overlap

• Wide LSA (112°–116°): Less overlap

More overlap boosts high-RPM performance, while less overlap increases idle stability.

2. Idle Quality

• A tight LSA gives the engine a lumpy, aggressive idle (common in race cams).

• A wider LSA smoothens idle and improves low-RPM manners.

3. Powerband & Torque Curve

• Tight LSA → Fast cylinder filling → Strong top-end power

• Wide LSA → Broader torque range → Better drivability

Street engines usually prefer a smooth, wide powerband. Drag engines often want maximum high-RPM power.

4. Engine Vacuum

More overlap (tight LSA) reduces vacuum, affecting:

• Braking assist

• Idle quality

• Air-fuel tuning

Wider LSA gives more stable vacuum for daily driving.

5. Forced Induction Setup

Turbocharged and supercharged engines often perform better with a slightly wider LSA to prevent boost from escaping during overlap.

How to Use This Lobe Separation Angle Calculator

Using the tool is simple – all you need are your camshaft’s centerline values.

Step-by-Step

1. Enter Intake Centerline
   You can find this on your cam card or by degreeing the cam with a degree wheel.

2. Enter Exhaust Centerline
   Provided by manufacturers or determined during camshaft installation.

3. Click “Calculate”
   The tool instantly computes your LSA using the industry-standard formula.

4. Interpret the Result

   • LSA < 110° → Aggressive powerband, rough idle

   • LSA 110°–114° → Balanced street performance

   • LSA > 114° → Smooth idle, better vacuum, wide torque spread

Real-World LSA Examples

Example 1: Daily Street Build

• Intake: 110°

• Exhaust: 114°

• LSA = 112°
  Gives great drivability and smooth idle.

Example 2: Drag Racing Engine

• Intake: 104°

• Exhaust: 108°

• LSA = 106°
  Produces max high-RPM horsepower with a choppy idle.

Example 3: Turbocharged Setup

• Intake: 112°

• Exhaust: 116°

• LSA = 114°
  Keeps overlap low to avoid boost loss and maintain efficient spool.

Important Things to Know About LSA

• You cannot adjust LSA manually – it’s built into the camshaft.

• Duration, lift, and valve timing also affect performance, not just LSA.

• Advancing or retarding a cam does NOT change the LSA, it only shifts the centerlines.

• A cam card sometimes shows “112 + 2”, meaning 2° intake advance is pre-ground.

Why This Calculator Is Useful

• Prevents mistakes in manual calculations

• Helps interpret cam cards faster

• Ideal for comparing different camshaft options

• Saves time for tuners, mechanics, and engine hobbyists

• Provides quick insights into how a cam will behave in your engine