Customer requested complete tear-down and inspection of Porsche 911 track car engine due to heavy oil leakage after previous rebuild. Vehicle was tested and inspected prior to disassembly, and determined that engine would require disassembly down to short-block only.
Engine was removed and dismantled down to short-block, with all components inspected, measured, and catalogued during the disassembly process. It was determined during the disassembly that the source of the oil leakage was primarily at the crankcase to cylinder-bore sealing surface. During component inspection, the root-cause was determined to be from improper deck height (cylinder and cylinder head stack height) and insufficient piston to cylinder head clearance.
The piston crown of multiple cylinders had impacted the respective cylinder heads enough to stretch the head studs and cause oil leakage, but not enough to result in a catastrophic failure. The brunt of the impact was taken by the piston and piston pin bores which were damaged where the pin circlips had been impacted.
Since this was discovered before a catastrophic failure, the engine was able to be saved and successfully rebuilt with corrected deck height, new Mahle pistons and cylinders, rebuilt original cylinder heads, updated components as requested by the customer.
Vehicle was reassembled and tuned post-rebuild, serviced and released to the customer.