Delkron TwinCa High Perfomance Cyli - Manual (Page 2)

Correct top compression ring and secondary compression ring end gap is
equal to .004” per inch of cylinder bore … example: 4.125” x .004” = .0165”
of ring end gap. Rounding this number to the next highest number is
permissible … example: .0165” rounds to .017”
DO OT round to the next lowest number … example: .0165” to .016”. It is
better to be slightly larger with your ring end gap than smaller. Insufficient
clearance on the compression rings can lead to “Ring Abutment” at
operating temperature while under compression causing irreparable engine
damage.
To achieve correct ring end gap when ring end gap is insufficient, too small,
grinding of the ring ends will be necessary. This can be done several
different ways (File / Bench Grinder / Ring Grinder / Etc.), but it is
recommended that a ring grinding tool be
used. After grinding of ring be
sure to deburr the ring ends prior to re-installing them into the cylinder bore.