As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) EXHAUST VALVE BROKE AT HEAD. BROKEN PART EJECTED THROUGH EXHAUST PORT. CYLINDER/VALVES/PISTON REPLACED. NEW VALVES ON ORDER FOR REMAINING CYLINDER. ENGINE HAS SPENT MOST OF ITS TOTAL TIME AT HIGH POWER AEROBATIC USE. (NEGLECTABLE WEAR ON PISTON CYLINDER). (TC NR 20070912002)