Regrind Camshaft: A Comprehensive Guide to Optimizing Engine Performance

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A regrind camshaft is a process where a camshaft is modified to alter its specifications, such as lift, duration, and lobe separation angle (LSA), to optimize engine performance. This process involves removing material from the camshaft lobes and reshaping them to the desired specifications, allowing for precise tuning of the engine’s power delivery and responsiveness.

Measurable and Quantifiable Data Points

  1. Lift: Camshaft lift is the maximum distance the valve is lifted from its seat during the camshaft lobe’s duration. It is typically measured in thousandths of an inch (thou) or millimeters (mm). For example, a high-performance camshaft may have a lift of 0.550″ (13.97mm) on the intake and 0.570″ (14.48mm) on the exhaust.

  2. Duration: Camshaft duration is the amount of time, measured in degrees of crankshaft rotation, that the valve is off its seat during the camshaft lobe’s duration. It is typically measured at 0.050″ (1.27mm) lift. For example, a high-performance camshaft may have an intake duration of 280 degrees and an exhaust duration of 290 degrees.

  3. Lobe Separation Angle (LSA): LSA is the angle between the intake and exhaust lobes on the camshaft, measured in degrees. It affects the overlap between the intake and exhaust valves and can significantly impact engine performance. For example, a high-performance camshaft may have an LSA of 112 degrees.

  4. Base Circle: The base circle is the smallest diameter of the camshaft lobe and is the point of reference for measuring lift. It is typically measured in inches or millimeters. For example, a high-performance camshaft may have a base circle diameter of 2.100″ (53.34mm).

  5. Ramp Acceleration: Ramp acceleration is the rate at which the valve accelerates as it moves off its seat. It is typically measured in degrees per thousandths of an inch (deg/thou) or degrees per millimeter (deg/mm). For example, a high-performance camshaft may have a ramp acceleration of 180 deg/thou (7.09 deg/mm) on the intake and 190 deg/thou (7.48 deg/mm) on the exhaust.

  6. Valve Spring Pressure: Valve spring pressure is the force required to keep the valve closed against the pressure of the intake or exhaust gases. It is typically measured in pounds per square inch (psi) or kilopascals (kPa). For example, a high-performance valve spring may have a pressure of 150 psi (1034 kPa).

Regrind Camshaft Technical Specifications

regrind camshaft

  1. Material: Camshafts are typically made from high-strength steel, such as 8620 or 9310, to withstand the forces and stresses of high-performance engines. These materials offer superior hardness, tensile strength, and fatigue resistance.

  2. Lobe Design: The lobe design of a regrind camshaft is crucial for optimizing engine performance. Aggressive lobe profiles with increased lift and duration are common in high-performance applications, as they can improve volumetric efficiency and power output.

  3. Lobe Finish: The lobe finish of a regrind camshaft is critical for its performance and durability. A smooth, polished finish with a surface roughness (Ra) of less than 0.2 microns can reduce friction and wear, while a rougher finish (Ra of 0.4-0.6 microns) can improve oil retention and lubrication.

  4. Lobe Hardness: The lobe hardness of a regrind camshaft is typically in the range of 58-62 HRC (Rockwell C scale) to withstand the forces and stresses of high-performance engines. Harder lobe materials can better resist wear and maintain their intended specifications over the engine’s lifespan.

  5. Lobe Profile: The lobe profile of a regrind camshaft can be symmetrical or asymmetrical, depending on the engine’s specific performance requirements. Symmetrical profiles are common in high-performance applications, while asymmetrical profiles can optimize engine performance in specific rpm ranges.

Regrind Camshaft DIY

Regrinding a camshaft is a complex and specialized process that requires specialized equipment and expertise. It is not recommended for the average DIY enthusiast. However, here are the general steps involved in the regrind camshaft process:

  1. Disassemble the Engine: The first step is to disassemble the engine and remove the camshaft.
  2. Measure the Camshaft: Accurately measure the camshaft to determine the desired specifications for the regrind.
  3. Design the New Lobe Profile: The new lobe profile must be designed to meet the desired performance characteristics of the engine.
  4. Mount the Camshaft: Securely mount the camshaft in a specialized camshaft grinding machine.
  5. Grind the Lobes: Use a precision grinding wheel to grind the lobes to the desired profile.
  6. Inspect the Camshaft: Thoroughly inspect the camshaft to ensure it meets the desired specifications.
  7. Reassemble the Engine: Install the regrind camshaft in the engine and reassemble the engine.

References

  1. Regrind Stock Cam? | Page 2 | Ford Mustang Forums – Corral.net
    https://www.corral.net/threads/regrind-stock-cam.1667513/page-2
  2. Custom cam regrind specs? – Mazda MX-6 Forum
    https://www.mx6.com/threads/custom-cam-regrind-specs.272193/
  3. Camshaft Regrind Thread | High-Performance Modifications
    https://www.500eboard.co/forums/threads/camshaft-regrind-thread.7513/