I’ve noticed this type of wear on a few CS engines that, as far as I know, have only been run on diesel. My conclusion on the cause has been faulty, broken or worn compression ring or lack of upper cylinder lubrication due to a blocked oil control ring and/or faulty engine breather. I believe the breather is designed to create a vacuum on the cylinder’s upward stroke and therefore draw oil into the void that is created?
If this wear is accelerated by the use of wmo then here are some possibilities I’ve thought of:
As far as I’m aware, wmo does burn hotter than standard diesel. In wmo burners, the flame length is increased and will therefore eventually burn the back out of chambers that are not long enough to accommodate the burner. This could account for the lack of lubrication on the exhaust side of the bore (lubricating oil vaporising on contact)
It’s my belief that the white ash created from burning wmo comes from the non-oil content. Again, with wmo burners, the finer I filter the oil, the less ash I get.
I’ve found that the greatest percentage of non-oil is below 1 micron so, if the ash is causing the problem in engines, filtering to ½ micron should improve the situation. It would certainly reduce the build up on injector tips.
It is worth noting that filter efficiency varies considerably so any reasonable test should be done with a known type. Sock type filters have the lowest efficiency. Cartridge filters normally have a percentage rating, some are as low as 60%.
So a 1 micron filter that is rated at 60% is probably no better than a 90% 5 micron.
‘Absolute’ filters will give the best results but are obviously more costly.
Many filters manufactured in China seem to have ratings above their actual efficiency.
Anyway, Happy, whatever it is you celebrate in your household, to you all.