Note that there is also oil on the threads of the sparkplugs. The oil on the sparkplugs above the tapered seal may be from the valve cover gasket.
•The oil on the threads of the sparkplugs below the tapered seal is definitely from the combustion chamber.
•The oil in the combustion chamber is due to excess oiling of the valve train overwhelming the valve seals.
•The excess oil to the valve train is being caused by a hydraulic cam core with a full oil groove on the rear journal over supplying oil to a mechanical valve train.
•The excess oil to the valve train starved the rod bearings of oil and that is the primary reason the rod bearings failed.
•Pre ignition-detonation was not the cause of the rod bearing failure. Enough pre ignition-detonation to wipe out the rod bearings would have left marks on the piston tops and ring lands and there is absolutely none.
