On a JMS 624 engine with approximately 16k operating hours with "H" series cylinder heads that had approximately 6k hours on the head, we discovered that the pre-chamber seating surface in the head was eroded or corroded such that we were barely able to seal the new pre-chambers. This was pretty typical across all 24 heads. These were the original pre-chambers installed with these new "H" series heads and it appears that the crush rings were installed "dry" which was the procedure at the time. Jenbacher has since changed ST-237, instructing technicians to apply Perfect Seal #4 or equivalent. This applies to both "F" and "H" cylinder heads.
Has any other users experienced erosion/corrosion in the pre-chamber seating surface of the cylinder heads and if so what was the feedback or direction from Jenbacher or your distributor?