[rtanner]

Originally Posted by Schurkey

1. How can adding oil decrease the pressure? What in a combustion chamber leaks MORE when oiled?

2. The FAA does not suggest a "wet" leakdown test where oil is added to the cylinder via the spark plug hole. They do accept an "oiled" re-test that involves running the engine in "CHAPTER 8. ENGINES, FUEL, EXHAUST, AND PROPELLERS; page 8".
http://rgl.faa.gov/Regulatory_and_Gu...apter%2008.pdf


My concern still stands: Does added oil via the spark-plug hole just blow out the ring gaps or other ring leakage points when the cylinder is pressurized? The result would be no difference in "wet" versus "dry" cylinder leakdown testing once the oil has moved down the piston.

Do it however you want then! Thanks for the FAA info come in handy if I ever work on a airplane.

[madokie]

i agree with hurrinhooser62, i don't use engine oil when installing piston w rings in bore, oil is like water is wont compress, i have seen in car mags a pan full of oil and piston dunked in oil and then assembled in bore, not needed !!!!, a light spray lube in bore and on piston is all you need for assembly.