# SDR 98ZZZX3443

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: September 4, 1998
- Submitted: March 26, 2000
- Operation: General aviation
- Aircraft: [N678DB](https://openairdocs.org/aircraft/N678DB), registered now
- Make and model: Cessna 421B
- Registry model: [Cessna 421B](https://openairdocs.org/model/cessna-421b) (OpenAirDocs)
- Aircraft serial: 4210876
- Engine: Cont GTSIO520H
- System (JASC): [8530 · Reciprocating Engine Cylinder Section](https://openairdocs.org/jasc/8530)
- Part: Valve
- Part number: TCM539988
- Condition: Mismanufactured
- Location: Rt Eng Intake
- Part time: 359 hours
- Stage of operation: IN
- Nature of condition: W
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/98ZZZX3443

## Discrepancy

DURING A PHASE INSPECTION, FOUND RIGHT ENGINE NR 5 CYLINDER LOW COMPRESSION 20/80, LEAKING BY INTAKE VALVE.  REMOVED CYLINDER AND FOUND INTAKE VALVE HAD APPROXIMATELY .005 INCH RIDGE COMPLETELY AROUND VALVE ABOVE SEAT.  SUSPECT VALVE WAS NOT PROPERLY HARDENED DURING MANUFACTURING PROCESS.

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