Interesting that I interpreted the original report of "Not to mention while not part of the CR fuel system every cylinder on both engines had cracked land rings" as being the Entablature Lands that the liner sits on, Merlyn interprets that as "We also had several engines with piston damage present which gives me food for thought over your remark concerning " lands " by which I take it you mean the piston lands, i.e. The areas each side of the ring contact with the piston." Just shows that every reader will produce a slightly different interpretations of the written word.
I agree with D. Winsor that it could be a water problem, in which case keep the settling and service Tanks hotter for longer, drain them regularly and also any other drains in the system. ( in the past I have found water to accumulate in the bottom of filters and replaced the drain plugs with a drain cock which can remove a surprising amount of water.) and make sure the purifier is set up right, if you have 2 purifiers run them both, either in series or in parallel but always at the slowest flow rate that will keep the service tank full.
A problem I had on one ship was that the HFO booster pumps were continually getting trashed, I found that someone had been putting fine filters on the suction side of the pumps, but because the ship had been changed to a heavier grade of F.O., they dropped the suction pressure at the pump inlet causing the fuel to boil and cause cavitation damage.Water accumulating in the bottom of the filter housing aggravated the problem.
The original design had called for course filters at the suction of the booster pump to protect them from damage and fine filters afterwards to protect the fuel injection equipment. A previous Chief Engineer and Super had decided that rather than ordering 2 different Micron filters, they would order all the same Micron rating, the average of the 2 original filters. As a result the booster pumps were trashed by cavitation and the Injection pumps by the large particles going through the filters.
It is always better to ask a stupid question than to do a stupid thing.