Who is building these grenades for you? We saw 68 national races on a GT motor with 14-1 compression 1.6L 9000RPM 192HP and then freshened it because the leakdown was over 10%
Since then it has done 12 nationals and is going fine. An IT motor should last 5 seasons or more including Enduros before it needs attention.They just arent that highly stressed!
Do you dyno these motors and shift at the proper RPM? Something just isnt right.

Dick Shine