Home > Tech Articles > Engine Specific > 20R/22R, RE, RT-E Top End > Engine – Cylinder Head ID

Engine – Cylinder Head ID


1975 1980 20R Cylinder Head:

  • Round Intake Port / Round Exhaust Port
  • 80 / 81cc Chamber
  • In. Valve Dia. 43mm / Ex. Valve Dia. 35mm


1981 / 84 22R / RE Cylinder Head:

  • Square Intake Port / Round Exhaust Port
  • 82 /83 cc Chamber
  • In. Valve Dia. 44.5mm / Ex. Valve Dia. 36.5mm


1985 / 95 22R / RE Cylinder Head:

  • Square Intake Port / Pear Shaped Exhaust Port
  • 58 cc Chamber or 22RET (Turbo)
  • In. Valve Dia. 44.5mm / Ex Valve Dia. 36.5mm


Cylinder Head Intake Air Flow (Aprox):

  • Stock: 130 CFM
  • Stage 2: 160 CFM
  • Stage 3: 200 CFM
  • Stage 5: 250 CFM