How to Read CP Wrist Pin Part Numbers & Horsepower Rating

Identifying a CP Piston Wrist Pin is easy thanks to their part numbering method:

Example: 866-2250-20CP3C

• First Three Digits Show Wrist pin diameter
• Second Four Digits Show Wrist Pin Length
• Third Two Digits = Wall thickness
• Fourth Two Digits = Brand
  • CP = CP-Carrillo
• Fifth Single Digit = Material
  • 1 = 5100 Chromoly
  • 3 = 9310 Steel
  • M = 300M
• Last Digit = Type
  • C = Chamfered
  • S = Non-Chamfered

More on CP Pin Materials & Horsepower Rating:

5100 Chromoly – Part # ending in CP1_

• 16CP1C = 100HP per cylinder
• 18CP1C = 135HP per cylinder
• 20CP1C = 175HP per cylinder

9310 Steel – Part # ending in CP3_

• 18CP3C = 9310 Steel = 175HP per cylinder
• 20CP3C = 9310 Steel = 225HP per cylinder
• 25CP3C = 9310 Steel = 300HP per cylinder
• 26CP3C = 9310 Steel = 300HP per cylinder

300M Material – Part # ending in CPM_

• 25CPMC = 300M material = 325HP per cylinder

Calculating Total Engine Horsepower Rating:

• 225 per cylinder x 4 cylinder engine = 900 HP 
• 225 per cylinder x 6 cylinder engine = 1350HP