Beginning in mid-to-late 2002, all engines after engine serial #1025386 in '02 (and all '03), Honda changed the design of the banjo bolt that supplies the piston sprayer (oil jet) with engine oil. This change improved flow to the sprayers and aided in preventing cylinder wall scoring, especially when operated at high RPMs on track. This modification is recommended for all affected 2002 and earlier S2000’s if not already done for maximum longevity. It really should be considered a requirement for any track or autocross vehicles.
Installation of these bolts requires dropping the oil pan, which can be done on-vehicle. While not an easy task, this can be completed within a few hours. Installation can be tricky, and proper torque of these is critical to insuring proper operation and to prevent the bolts from loosening under continuous high-speed operation, such as on track.