Crankshaft Standard (STD). Porsche 911 2.0ltr / 2.2ltr / 914-6

Standard Size Crankshaft (STD)
The standard size (STD) engine crankshaft is an essential rotating component for the early air-cooled Porsche models.

Fits:

• Porsche 911 1965-1968 2.0L / 912 SWB (F)
• Porsche 911 1968-1973 2.2L / 2.4L / 2.7L RS LWB (F)
• Porsche 914-6 2.0L (1970-1976)

These first-generation air-cooled flat-six engines rely heavily on the strength, balance and accuracy of the crankshaft to deliver the smooth, free-revving performance that made the classic 911 legendary.

Whether performing a true-to-original restoration or a full bottom-end rebuild, this crankshaft ensures proper bearing clearances, smooth rotation and the reliability required to support both naturally aspirated and early turbocharged Porsche engines.

What the Crankshaft Does

This crankshaft plays a central role in engine operation by:

• Transforming piston movement into rotational torque to drive the transmission
  
• Maintaining exact journal sizing for correct oil film and bearing support
  
• Ensuring balanced rotation across the entire RPM range
  
• Supporting reliable lubrication through precision oil galleries
  
• Handling high load and thermal stress typical of air-cooled performance engines
  
• Providing dependable bottom-end stability for both normally aspirated and turbocharged setups

Without a properly sized and balanced crankshaft, the engine cannot run smoothly or reliably.

Why Crankshafts Can Fail

Although Porsche’s air-cooled crankshafts are renowned for durability, age, performance use and lubrication issues can lead to failure. Common causes include:

• Oil starvation causing bearing damage and journal scoring
  
• Contamination in the oil system leading to abrasive wear
  
• High-mileage fatigue resulting in stress cracks or journal out-of-round conditions
  
• Overheating reducing metallurgical strength
  
• Incorrect machining or imbalance from past rebuilds
  
• Detonation or pre-ignition placing excessive load on journals
  
• Corrosion from long storage or moisture intrusion

Symptoms can include low oil pressure, vibration, bearing noise, metal debris in the oil, or excessive crankshaft end-float.

Why You Should Replace a Worn or Damaged Crankshaft

Installing a new or precision-engineered standard size crankshaft—matched to original Porsche tolerances—provides the foundation for a reliable, long-lasting engine rebuild.

Benefits include:

• Restored bearing clearance and proper lubrication
• Smooth rotational balance and reduced engine vibration
• Improved reliability for both standard and turbocharged engines
• Protection against catastrophic bottom-end failures
• Extended lifespan for connecting rods, bearings and pistons
• Consistent performance in high-heat air-cooled environments

For early air-cooled Porsche models, the crankshaft is one of the most critical components that determines the success and durability of any engine rebuild.