Not
exactly related, but with respect to the effects on the engine and lubricant of high cylinder temperatures, this is the summary of one of this month's AAIB investigation reports:
Two aircraft with Jabiru 2200 engines fitted suffered similar engine failures. Both engines had achieved less than 50 hours of usage since they were manufactured. The failures were caused by high temperatures generated within the cylinders causing softening of the piston material which lead to the piston rings becoming trapped in their grooves. This allowed engine lubricating oil and/or oil vapour to enter the combustion chamber which allowed pre-ignition to occur, leading to burn-through of the piston crown. Once the burn-through was severe enough, combustion gasses entered the engine crankcase which pressurised it forcing the engine lubricating oil to be expelled overboard via the engine exhaust and crankcase breather tube. Both engines had been modified at manufacture to comply with Jabiru Service Letter JSL 002-1 titled ‘Jabiru Engine Economy Tuning’ which introduced lean burn jets into the carburettor.